Merge remote-tracking branch 'origin/main' into PR-1548-fix-group-page-lists

config/config.example.yml

@@ -258,3 +258,10 @@ mediaViewer:
 info:
   enableEndUserAgreement: true
   enablePrivacyStatement: true
+# Home Page
+homePage:
+  recentSubmissions:
+	# The number of item showing in recent submission components
+      pageSize: 5
+	# Sort record of recent submission
+      sortField: 'dc.date.accessioned'

cypress/.gitignore

@@ -1,2 +1,3 @@
 screenshots/
 videos/
+downloads/

scripts/test-rest.ts

@@ -22,7 +22,13 @@ console.log(`...Testing connection to REST API at ${restUrl}...\n`);
 if (appConfig.rest.ssl) {
     const req = https.request(restUrl, (res) => {
         console.log(`RESPONSE: ${res.statusCode} ${res.statusMessage} \n`);
-        res.on('data', (data) => {
+        // We will keep reading data until the 'end' event fires.
+        // This ensures we don't just read the first chunk.
+        let data = '';
+        res.on('data', (chunk) => {
+            data += chunk;
+        });
+        res.on('end', () => {
             checkJSONResponse(data);
         });
     });
@@ -35,7 +41,13 @@ if (appConfig.rest.ssl) {
 } else {
     const req = http.request(restUrl, (res) => {
         console.log(`RESPONSE: ${res.statusCode} ${res.statusMessage} \n`);
-        res.on('data', (data) => {
+        // We will keep reading data until the 'end' event fires.
+        // This ensures we don't just read the first chunk.
+        let data = '';
+        res.on('data', (chunk) => {
+            data += chunk;
+        });
+        res.on('end', () => {
             checkJSONResponse(data);
         });
     });

src/app/access-control/epeople-registry/eperson-form/eperson-form.component.spec.ts

@@ -177,7 +177,7 @@ describe('EPersonFormComponent', () => {
 
     });
     groupsDataService = jasmine.createSpyObj('groupsDataService', {
-      findAllByHref: createSuccessfulRemoteDataObject$(createPaginatedList([])),
+      findListByHref: createSuccessfulRemoteDataObject$(createPaginatedList([])),
       getGroupRegistryRouterLink: ''
     });
 

src/app/access-control/epeople-registry/eperson-form/eperson-form.component.ts

@@ -265,7 +265,7 @@ export class EPersonFormComponent implements OnInit, OnDestroy {
       this.formGroup = this.formBuilderService.createFormGroup(this.formModel);
       this.subs.push(this.epersonService.getActiveEPerson().subscribe((eperson: EPerson) => {
         if (eperson != null) {
-          this.groups = this.groupsDataService.findAllByHref(eperson._links.groups.href, {
+          this.groups = this.groupsDataService.findListByHref(eperson._links.groups.href, {
             currentPage: 1,
             elementsPerPage: this.config.pageSize
           });
@@ -297,7 +297,7 @@ export class EPersonFormComponent implements OnInit, OnDestroy {
         }),
         switchMap(([eperson, findListOptions]) => {
           if (eperson != null) {
-            return this.groupsDataService.findAllByHref(eperson._links.groups.href, findListOptions, true, true, followLink('object'));
+            return this.groupsDataService.findListByHref(eperson._links.groups.href, findListOptions, true, true, followLink('object'));
           }
           return observableOf(undefined);
         })
@@ -554,7 +554,7 @@ export class EPersonFormComponent implements OnInit, OnDestroy {
    */
   private updateGroups(options) {
     this.subs.push(this.epersonService.getActiveEPerson().subscribe((eperson: EPerson) => {
-      this.groups = this.groupsDataService.findAllByHref(eperson._links.groups.href, options);
+      this.groups = this.groupsDataService.findListByHref(eperson._links.groups.href, options);
     }));
   }
 }

src/app/access-control/group-registry/group-form/members-list/members-list.component.spec.ts

@@ -53,7 +53,7 @@ describe('MembersListComponent', () => {
       activeGroup: activeGroup,
       epersonMembers: epersonMembers,
       subgroupMembers: subgroupMembers,
-      findAllByHref(href: string): Observable<RemoteData<PaginatedList<EPerson>>> {
+      findListByHref(href: string): Observable<RemoteData<PaginatedList<EPerson>>> {
         return createSuccessfulRemoteDataObject$(buildPaginatedList<EPerson>(new PageInfo(), groupsDataServiceStub.getEPersonMembers()));
       },
       searchByScope(scope: string, query: string): Observable<RemoteData<PaginatedList<EPerson>>> {

src/app/access-control/group-registry/group-form/members-list/members-list.component.ts

@@ -130,7 +130,7 @@ export class MembersListComponent implements OnInit, OnDestroy {
     this.subs.set(SubKey.MembersDTO,
       this.paginationService.getCurrentPagination(this.config.id, this.config).pipe(
         switchMap((currentPagination) => {
-          return this.ePersonDataService.findAllByHref(this.groupBeingEdited._links.epersons.href, {
+          return this.ePersonDataService.findListByHref(this.groupBeingEdited._links.epersons.href, {
               currentPage: currentPagination.currentPage,
               elementsPerPage: currentPagination.pageSize
             }
@@ -172,7 +172,7 @@ export class MembersListComponent implements OnInit, OnDestroy {
     return this.groupDataService.getActiveGroup().pipe(take(1),
       mergeMap((group: Group) => {
         if (group != null) {
-          return this.ePersonDataService.findAllByHref(group._links.epersons.href, {
+          return this.ePersonDataService.findListByHref(group._links.epersons.href, {
             currentPage: 1,
             elementsPerPage: 9999
           })

src/app/access-control/group-registry/group-form/subgroup-list/subgroups-list.component.spec.ts

@@ -65,7 +65,7 @@ describe('SubgroupsListComponent', () => {
       getSubgroups(): Group {
         return this.activeGroup;
       },
-      findAllByHref(href: string): Observable<RemoteData<PaginatedList<Group>>> {
+      findListByHref(href: string): Observable<RemoteData<PaginatedList<Group>>> {
         return this.subgroups$.pipe(
           map((currentGroups: Group[]) => {
             return createSuccessfulRemoteDataObject(buildPaginatedList<Group>(new PageInfo(), currentGroups));

src/app/access-control/group-registry/group-form/subgroup-list/subgroups-list.component.ts

@@ -115,7 +115,7 @@ export class SubgroupsListComponent implements OnInit, OnDestroy {
     this.subs.set(
       SubKey.Members,
       this.paginationService.getCurrentPagination(this.config.id, this.config).pipe(
-        switchMap((config) => this.groupDataService.findAllByHref(this.groupBeingEdited._links.subgroups.href, {
+        switchMap((config) => this.groupDataService.findListByHref(this.groupBeingEdited._links.subgroups.href, {
             currentPage: config.currentPage,
             elementsPerPage: config.pageSize
           },
@@ -139,7 +139,7 @@ export class SubgroupsListComponent implements OnInit, OnDestroy {
           if (activeGroup.uuid === possibleSubgroup.uuid) {
             return observableOf(false);
           } else {
-            return this.groupDataService.findAllByHref(activeGroup._links.subgroups.href, {
+            return this.groupDataService.findListByHref(activeGroup._links.subgroups.href, {
               currentPage: 1,
               elementsPerPage: 9999
             })

src/app/access-control/group-registry/groups-registry.component.spec.ts

@@ -69,7 +69,7 @@ describe('GroupRegistryComponent', () => {
     mockGroups = [GroupMock, GroupMock2];
     mockEPeople = [EPersonMock, EPersonMock2];
     ePersonDataServiceStub = {
-      findAllByHref(href: string): Observable<RemoteData<PaginatedList<EPerson>>> {
+      findListByHref(href: string): Observable<RemoteData<PaginatedList<EPerson>>> {
         switch (href) {
           case 'https://dspace.4science.it/dspace-spring-rest/api/eperson/groups/testgroupid2/epersons':
             return createSuccessfulRemoteDataObject$(buildPaginatedList(new PageInfo({
@@ -97,7 +97,7 @@ describe('GroupRegistryComponent', () => {
     };
     groupsDataServiceStub = {
       allGroups: mockGroups,
-      findAllByHref(href: string): Observable<RemoteData<PaginatedList<Group>>> {
+      findListByHref(href: string): Observable<RemoteData<PaginatedList<Group>>> {
         switch (href) {
           case 'https://dspace.4science.it/dspace-spring-rest/api/eperson/groups/testgroupid2/groups':
             return createSuccessfulRemoteDataObject$(buildPaginatedList(new PageInfo({

src/app/access-control/group-registry/groups-registry.component.ts

@@ -213,7 +213,7 @@ export class GroupsRegistryComponent implements OnInit, OnDestroy {
    * @param group
    */
   getMembers(group: Group): Observable<RemoteData<PaginatedList<EPerson>>> {
-    return this.ePersonDataService.findAllByHref(group._links.epersons.href).pipe(getFirstSucceededRemoteData());
+    return this.ePersonDataService.findListByHref(group._links.epersons.href).pipe(getFirstSucceededRemoteData());
   }
 
   /**
@@ -221,7 +221,7 @@ export class GroupsRegistryComponent implements OnInit, OnDestroy {
    * @param group
    */
   getSubgroups(group: Group): Observable<RemoteData<PaginatedList<Group>>> {
-    return this.groupService.findAllByHref(group._links.subgroups.href).pipe(getFirstSucceededRemoteData());
+    return this.groupService.findListByHref(group._links.subgroups.href).pipe(getFirstSucceededRemoteData());
   }
 
   /**

src/app/collection-page/collection-form/collection-form.component.ts

@@ -16,7 +16,7 @@ import { CommunityDataService } from '../../core/data/community-data.service';
 import { AuthService } from '../../core/auth/auth.service';
 import { RequestService } from '../../core/data/request.service';
 import { ObjectCacheService } from '../../core/cache/object-cache.service';
-import { EntityTypeService } from '../../core/data/entity-type.service';
+import { EntityTypeDataService } from '../../core/data/entity-type-data.service';
 import { ItemType } from '../../core/shared/item-relationships/item-type.model';
 import { MetadataValue } from '../../core/shared/metadata.models';
 import { getFirstSucceededRemoteListPayload } from '../../core/shared/operators';
@@ -61,7 +61,7 @@ export class CollectionFormComponent extends ComColFormComponent<Collection> imp
                      protected dsoService: CommunityDataService,
                      protected requestService: RequestService,
                      protected objectCache: ObjectCacheService,
-                     protected entityTypeService: EntityTypeService) {
+                     protected entityTypeService: EntityTypeDataService) {
     super(formService, translate, notificationsService, authService, requestService, objectCache);
   }
 

src/app/collection-page/collection-item-mapper/collection-item-mapper.component.spec.ts

@@ -94,7 +94,7 @@ describe('CollectionItemMapperComponent', () => {
   const emptyList = createSuccessfulRemoteDataObject(createPaginatedList([]));
   const itemDataServiceStub = {
     mapToCollection: () => createSuccessfulRemoteDataObject$({}),
-    findAllByHref: () => observableOf(emptyList)
+    findListByHref: () => observableOf(emptyList),
   };
   const activatedRouteStub = {
     parent: {
@@ -152,7 +152,7 @@ describe('CollectionItemMapperComponent', () => {
   });
 
   const groupDataService = jasmine.createSpyObj('groupsDataService', {
-    findAllByHref: createSuccessfulRemoteDataObject$(createPaginatedList([])),
+    findListByHref: createSuccessfulRemoteDataObject$(createPaginatedList([])),
     getGroupRegistryRouterLink: '',
     getUUIDFromString: '',
   });

src/app/collection-page/collection-item-mapper/collection-item-mapper.component.ts

@@ -143,7 +143,7 @@ export class CollectionItemMapperComponent implements OnInit {
         if (shouldUpdate === true) {
           this.shouldUpdate$.next(false);
         }
-        return this.itemDataService.findAllByHref(collectionRD.payload._links.mappedItems.href, Object.assign(options, {
+        return this.itemDataService.findListByHref(collectionRD.payload._links.mappedItems.href, Object.assign(options, {
           sort: this.defaultSortOptions
         }),!shouldUpdate, false, followLink('owningCollection')).pipe(
           getAllSucceededRemoteData()

src/app/collection-page/edit-collection-page/collection-metadata/collection-metadata.component.spec.ts

@@ -13,7 +13,7 @@ import { Item } from '../../../core/shared/item.model';
 import { ItemTemplateDataService } from '../../../core/data/item-template-data.service';
 import { Collection } from '../../../core/shared/collection.model';
 import { RequestService } from '../../../core/data/request.service';
-import { createSuccessfulRemoteDataObject, createSuccessfulRemoteDataObject$ } from '../../../shared/remote-data.utils';
+import { createFailedRemoteDataObject$, createSuccessfulRemoteDataObject, createSuccessfulRemoteDataObject$ } from '../../../shared/remote-data.utils';
 import { getCollectionItemTemplateRoute } from '../../collection-page-routing-paths';
 
 describe('CollectionMetadataComponent', () => {
@@ -39,8 +39,8 @@ describe('CollectionMetadataComponent', () => {
 
   const itemTemplateServiceStub = jasmine.createSpyObj('itemTemplateService', {
     findByCollectionID: createSuccessfulRemoteDataObject$(template),
-    create: createSuccessfulRemoteDataObject$(template),
+    createByCollectionID: createSuccessfulRemoteDataObject$(template),
-    deleteByCollectionID: observableOf(true),
+    delete: observableOf(true),
     getCollectionEndpoint: observableOf(collectionTemplateHref),
   });
 
@@ -91,12 +91,12 @@ describe('CollectionMetadataComponent', () => {
 
   describe('deleteItemTemplate', () => {
     beforeEach(() => {
-      (itemTemplateService.deleteByCollectionID as jasmine.Spy).and.returnValue(observableOf(true));
+      (itemTemplateService.delete as jasmine.Spy).and.returnValue(createSuccessfulRemoteDataObject$({}));
       comp.deleteItemTemplate();
     });
 
-    it('should call ItemTemplateService.deleteByCollectionID', () => {
+    it('should call ItemTemplateService.delete', () => {
-      expect(itemTemplateService.deleteByCollectionID).toHaveBeenCalledWith(template, 'collection-id');
+      expect(itemTemplateService.delete).toHaveBeenCalledWith(template.uuid);
     });
 
     describe('when delete returns a success', () => {
@@ -107,7 +107,7 @@ describe('CollectionMetadataComponent', () => {
 
     describe('when delete returns a failure', () => {
       beforeEach(() => {
-        (itemTemplateService.deleteByCollectionID as jasmine.Spy).and.returnValue(observableOf(false));
+        (itemTemplateService.delete as jasmine.Spy).and.returnValue(createFailedRemoteDataObject$());
         comp.deleteItemTemplate();
       });
 

src/app/collection-page/edit-collection-page/collection-metadata/collection-metadata.component.ts

@@ -7,12 +7,14 @@ import { ItemTemplateDataService } from '../../../core/data/item-template-data.s
 import { combineLatest as combineLatestObservable, Observable } from 'rxjs';
 import { RemoteData } from '../../../core/data/remote-data';
 import { Item } from '../../../core/shared/item.model';
-import { getFirstSucceededRemoteDataPayload } from '../../../core/shared/operators';
+import { getFirstCompletedRemoteData, getFirstSucceededRemoteDataPayload } from '../../../core/shared/operators';
-import { switchMap } from 'rxjs/operators';
+import { map, switchMap } from 'rxjs/operators';
 import { NotificationsService } from '../../../shared/notifications/notifications.service';
 import { TranslateService } from '@ngx-translate/core';
 import { RequestService } from '../../../core/data/request.service';
 import { getCollectionItemTemplateRoute } from '../../collection-page-routing-paths';
+import { NoContent } from '../../../core/shared/NoContent.model';
+import { hasValue } from '../../../shared/empty.util';
 
 /**
  * Component for editing a collection's metadata
@@ -65,7 +67,7 @@ export class CollectionMetadataComponent extends ComcolMetadataComponent<Collect
       getFirstSucceededRemoteDataPayload(),
     );
     const template$ = collection$.pipe(
-      switchMap((collection: Collection) => this.itemTemplateService.create(new Item(), collection.uuid).pipe(
+      switchMap((collection: Collection) => this.itemTemplateService.createByCollectionID(new Item(), collection.uuid).pipe(
         getFirstSucceededRemoteDataPayload(),
       )),
     );
@@ -83,18 +85,15 @@ export class CollectionMetadataComponent extends ComcolMetadataComponent<Collect
    * Delete the item template from the collection
    */
   deleteItemTemplate() {
-    const collection$ = this.dsoRD$.pipe(
+    this.dsoRD$.pipe(
       getFirstSucceededRemoteDataPayload(),
-    );
+      switchMap((collection: Collection) => this.itemTemplateService.findByCollectionID(collection.uuid)),
-    const template$ = collection$.pipe(
-      switchMap((collection: Collection) => this.itemTemplateService.findByCollectionID(collection.uuid).pipe(
       getFirstSucceededRemoteDataPayload(),
-      )),
+      switchMap((template) => {
-    );
+        return this.itemTemplateService.delete(template.uuid);
-    combineLatestObservable(collection$, template$).pipe(
+      }),
-      switchMap(([collection, template]) => {
+      getFirstCompletedRemoteData(),
-        return this.itemTemplateService.deleteByCollectionID(template, collection.uuid);
+      map((response: RemoteData<NoContent>) => hasValue(response) && response.hasSucceeded),
-      })
     ).subscribe((success: boolean) => {
       if (success) {
         this.notificationsService.success(null, this.translate.get('collection.edit.template.notifications.delete.success'));

src/app/community-page/sub-collection-list/community-page-sub-collection-list.component.spec.ts

@@ -135,7 +135,7 @@ describe('CommunityPageSubCollectionList Component', () => {
   });
 
   const groupDataService = jasmine.createSpyObj('groupsDataService', {
-    findAllByHref: createSuccessfulRemoteDataObject$(createPaginatedList([])),
+    findListByHref: createSuccessfulRemoteDataObject$(createPaginatedList([])),
     getGroupRegistryRouterLink: '',
     getUUIDFromString: '',
   });

src/app/community-page/sub-community-list/community-page-sub-community-list.component.spec.ts

@@ -131,7 +131,7 @@ describe('CommunityPageSubCommunityListComponent Component', () => {
   });
 
   const groupDataService = jasmine.createSpyObj('groupsDataService', {
-    findAllByHref: createSuccessfulRemoteDataObject$(createPaginatedList([])),
+    findListByHref: createSuccessfulRemoteDataObject$(createPaginatedList([])),
     getGroupRegistryRouterLink: '',
     getUUIDFromString: '',
   });

src/app/core/breadcrumbs/dso-breadcrumb.resolver.ts

@@ -2,23 +2,26 @@ import { BreadcrumbConfig } from '../../breadcrumbs/breadcrumb/breadcrumb-config
 import { Injectable } from '@angular/core';
 import { ActivatedRouteSnapshot, Resolve, RouterStateSnapshot } from '@angular/router';
 import { DSOBreadcrumbsService } from './dso-breadcrumbs.service';
-import { DataService } from '../data/data.service';
+import { getFirstCompletedRemoteData, getRemoteDataPayload } from '../shared/operators';
-import { getRemoteDataPayload, getFirstCompletedRemoteData } from '../shared/operators';
 import { map } from 'rxjs/operators';
 import { Observable } from 'rxjs';
 import { DSpaceObject } from '../shared/dspace-object.model';
 import { ChildHALResource } from '../shared/child-hal-resource.model';
 import { FollowLinkConfig } from '../../shared/utils/follow-link-config.model';
 import { hasValue } from '../../shared/empty.util';
+import { IdentifiableDataService } from '../data/base/identifiable-data.service';
 
 /**
  * The class that resolves the BreadcrumbConfig object for a DSpaceObject
  */
 @Injectable({
-  providedIn: 'root'
+  providedIn: 'root',
 })
 export abstract class DSOBreadcrumbResolver<T extends ChildHALResource & DSpaceObject> implements Resolve<BreadcrumbConfig<T>> {
-  constructor(protected breadcrumbService: DSOBreadcrumbsService, protected dataService: DataService<T>) {
+  protected constructor(
+    protected breadcrumbService: DSOBreadcrumbsService,
+    protected dataService: IdentifiableDataService<T>,
+  ) {
   }
 
   /**

src/app/core/browse/browse-definition-data.service.spec.ts

@@ -5,15 +5,9 @@ import { FindListOptions } from '../data/find-list-options.model';
 
 describe(`BrowseDefinitionDataService`, () => {
   let service: BrowseDefinitionDataService;
-  const dataServiceImplSpy = jasmine.createSpyObj('dataService', {
+  const findAllDataSpy = jasmine.createSpyObj('findAllData', {
     findAll: EMPTY,
-    findByHref: EMPTY,
-    findAllByHref: EMPTY,
-    findById: EMPTY,
   });
-  const hrefAll = 'https://rest.api/server/api/discover/browses';
-  const hrefSingle = 'https://rest.api/server/api/discover/browses/author';
-  const id = 'author';
   const options = new FindListOptions();
   const linksToFollow = [
     followLink('entries'),
@@ -21,35 +15,14 @@ describe(`BrowseDefinitionDataService`, () => {
   ];
 
   beforeEach(() => {
-    service = new BrowseDefinitionDataService(null, null, null, null, null, null, null, null);
+    service = new BrowseDefinitionDataService(null, null, null, null);
-    (service as any).dataService = dataServiceImplSpy;
+    (service as any).findAllData = findAllDataSpy;
   });
 
   describe(`findAll`, () => {
-    it(`should call findAll on DataServiceImpl`, () => {
+    it(`should call findAll on findAllData`, () => {
       service.findAll(options, true, false, ...linksToFollow);
-      expect(dataServiceImplSpy.findAll).toHaveBeenCalledWith(options, true, false, ...linksToFollow);
+      expect(findAllDataSpy.findAll).toHaveBeenCalledWith(options, true, false, ...linksToFollow);
-    });
-  });
-
-  describe(`findByHref`, () => {
-    it(`should call findByHref on DataServiceImpl`, () => {
-      service.findByHref(hrefSingle, true, false, ...linksToFollow);
-      expect(dataServiceImplSpy.findByHref).toHaveBeenCalledWith(hrefSingle, true, false, ...linksToFollow);
-    });
-  });
-
-  describe(`findAllByHref`, () => {
-    it(`should call findAllByHref on DataServiceImpl`, () => {
-      service.findAllByHref(hrefAll, options, true, false, ...linksToFollow);
-      expect(dataServiceImplSpy.findAllByHref).toHaveBeenCalledWith(hrefAll, options, true, false, ...linksToFollow);
-    });
-  });
-
-  describe(`findById`, () => {
-    it(`should call findById on DataServiceImpl`, () => {
-      service.findAllByHref(id, options, true, false, ...linksToFollow);
-      expect(dataServiceImplSpy.findAllByHref).toHaveBeenCalledWith(id, options, true, false, ...linksToFollow);
     });
   });
 });

src/app/core/browse/browse-definition-data.service.ts

@@ -1,61 +1,38 @@
-/* eslint-disable max-classes-per-file */
 import { Injectable } from '@angular/core';
-import { dataService } from '../cache/builders/build-decorators';
 import { BROWSE_DEFINITION } from '../shared/browse-definition.resource-type';
-import { DataService } from '../data/data.service';
 import { BrowseDefinition } from '../shared/browse-definition.model';
 import { RequestService } from '../data/request.service';
 import { RemoteDataBuildService } from '../cache/builders/remote-data-build.service';
-import { Store } from '@ngrx/store';
 import { ObjectCacheService } from '../cache/object-cache.service';
 import { HALEndpointService } from '../shared/hal-endpoint.service';
-import { NotificationsService } from '../../shared/notifications/notifications.service';
-import { HttpClient } from '@angular/common/http';
-import { DefaultChangeAnalyzer } from '../data/default-change-analyzer.service';
 import { FollowLinkConfig } from '../../shared/utils/follow-link-config.model';
 import { Observable } from 'rxjs';
 import { RemoteData } from '../data/remote-data';
 import { PaginatedList } from '../data/paginated-list.model';
-import { CoreState } from '../core-state.model';
 import { FindListOptions } from '../data/find-list-options.model';
+import { IdentifiableDataService } from '../data/base/identifiable-data.service';
+import { FindAllData, FindAllDataImpl } from '../data/base/find-all-data';
+import { dataService } from '../data/base/data-service.decorator';
 
-
+/**
-class DataServiceImpl extends DataService<BrowseDefinition> {
+ * Data service responsible for retrieving browse definitions from the REST server
-  protected linkPath = 'browses';
+ */
-
-  constructor(
-    protected requestService: RequestService,
-    protected rdbService: RemoteDataBuildService,
-    protected store: Store<CoreState>,
-    protected objectCache: ObjectCacheService,
-    protected halService: HALEndpointService,
-    protected notificationsService: NotificationsService,
-    protected http: HttpClient,
-    protected comparator: DefaultChangeAnalyzer<BrowseDefinition>) {
-    super();
-  }
-}
-
 @Injectable({
-  providedIn: 'root'
+  providedIn: 'root',
 })
 @dataService(BROWSE_DEFINITION)
-export class BrowseDefinitionDataService {
+export class BrowseDefinitionDataService extends IdentifiableDataService<BrowseDefinition> implements FindAllData<BrowseDefinition> {
-  /**
+  private findAllData: FindAllDataImpl<BrowseDefinition>;
-   * A private DataService instance to delegate specific methods to.
-   */
-  private dataService: DataServiceImpl;
 
   constructor(
     protected requestService: RequestService,
     protected rdbService: RemoteDataBuildService,
-    protected store: Store<CoreState>,
     protected objectCache: ObjectCacheService,
     protected halService: HALEndpointService,
-    protected notificationsService: NotificationsService,
+  ) {
-    protected http: HttpClient,
+    super('browses', requestService, rdbService, objectCache, halService);
-    protected comparator: DefaultChangeAnalyzer<BrowseDefinition>) {
+
-    this.dataService = new DataServiceImpl(requestService, rdbService, null, objectCache, halService, notificationsService, http, comparator);
+    this.findAllData = new FindAllDataImpl(this.linkPath, requestService, rdbService, objectCache, halService, this.responseMsToLive);
   }
 
   /**
@@ -69,57 +46,11 @@ export class BrowseDefinitionDataService {
    *                                    requested after the response becomes stale
    * @param linksToFollow               List of {@link FollowLinkConfig} that indicate which
    *                                    {@link HALLink}s should be automatically resolved
-   * @return {Observable<RemoteData<PaginatedList<BrowseDefinition>>>}
+   * @return {Observable<RemoteData<PaginatedList<T>>>}
    *    Return an observable that emits object list
    */
   findAll(options: FindListOptions = {}, useCachedVersionIfAvailable = true, reRequestOnStale = true, ...linksToFollow: FollowLinkConfig<BrowseDefinition>[]): Observable<RemoteData<PaginatedList<BrowseDefinition>>> {
-    return this.dataService.findAll(options, useCachedVersionIfAvailable, reRequestOnStale, ...linksToFollow);
+    return this.findAllData.findAll(options, useCachedVersionIfAvailable, reRequestOnStale, ...linksToFollow);
-  }
-
-  /**
-   * Returns an observable of {@link RemoteData} of an {@link BrowseDefinition}, based on an href, with a list of {@link FollowLinkConfig},
-   * to automatically resolve {@link HALLink}s of the {@link BrowseDefinition}
-   * @param href                        The url of {@link BrowseDefinition} we want to retrieve
-   * @param useCachedVersionIfAvailable If this is true, the request will only be sent if there's
-   *                                    no valid cached version. Defaults to true
-   * @param reRequestOnStale            Whether or not the request should automatically be re-
-   *                                    requested after the response becomes stale
-   * @param linksToFollow               List of {@link FollowLinkConfig} that indicate which
-   *                                    {@link HALLink}s should be automatically resolved
-   */
-  findByHref(href: string, useCachedVersionIfAvailable = true, reRequestOnStale = true, ...linksToFollow: FollowLinkConfig<BrowseDefinition>[]): Observable<RemoteData<BrowseDefinition>> {
-    return this.dataService.findByHref(href, useCachedVersionIfAvailable, reRequestOnStale, ...linksToFollow);
-  }
-
-  /**
-   * Returns a list of observables of {@link RemoteData} of {@link BrowseDefinition}s, based on an href, with a list of {@link FollowLinkConfig},
-   * to automatically resolve {@link HALLink}s of the {@link BrowseDefinition}
-   * @param href                        The url of object we want to retrieve
-   * @param findListOptions             Find list options object
-   * @param useCachedVersionIfAvailable If this is true, the request will only be sent if there's
-   *                                    no valid cached version. Defaults to true
-   * @param reRequestOnStale            Whether or not the request should automatically be re-
-   *                                    requested after the response becomes stale
-   * @param linksToFollow               List of {@link FollowLinkConfig} that indicate which
-   *                                    {@link HALLink}s should be automatically resolved
-   */
-  findAllByHref(href: string, findListOptions: FindListOptions = {}, useCachedVersionIfAvailable = true, reRequestOnStale = true, ...linksToFollow: FollowLinkConfig<BrowseDefinition>[]): Observable<RemoteData<PaginatedList<BrowseDefinition>>> {
-    return this.dataService.findAllByHref(href, findListOptions, useCachedVersionIfAvailable, reRequestOnStale, ...linksToFollow);
-  }
-
-  /**
-   * Returns an observable of {@link RemoteData} of an object, based on its ID, with a list of
-   * {@link FollowLinkConfig}, to automatically resolve {@link HALLink}s of the object
-   * @param id                          ID of object we want to retrieve
-   * @param useCachedVersionIfAvailable If this is true, the request will only be sent if there's
-   *                                    no valid cached version. Defaults to true
-   * @param reRequestOnStale            Whether or not the request should automatically be re-
-   *                                    requested after the response becomes stale
-   * @param linksToFollow               List of {@link FollowLinkConfig} that indicate which
-   *                                    {@link HALLink}s should be automatically resolved
-   */
-  findById(id: string, useCachedVersionIfAvailable = true, reRequestOnStale = true, ...linksToFollow: FollowLinkConfig<BrowseDefinition>[]): Observable<RemoteData<BrowseDefinition>> {
-    return this.dataService.findById(id, useCachedVersionIfAvailable, reRequestOnStale, ...linksToFollow);
   }
 }
 

src/app/core/browse/browse.service.spec.ts

@@ -139,13 +139,13 @@ describe('BrowseService', () => {
     });
 
     describe('when getBrowseEntriesFor is called with a valid browse definition id', () => {
-      it('should call hrefOnlyDataService.findAllByHref with the expected href', () => {
+      it('should call hrefOnlyDataService.findListByHref with the expected href', () => {
         const expected = browseDefinitions[1]._links.entries.href;
 
         scheduler.schedule(() => service.getBrowseEntriesFor(new BrowseEntrySearchOptions(browseDefinitions[1].id)).subscribe());
         scheduler.flush();
 
-        expect(getFirstUsedArgumentOfSpyMethod(hrefOnlyDataService.findAllByHref)).toBeObservable(cold('(a|)', {
+        expect(getFirstUsedArgumentOfSpyMethod(hrefOnlyDataService.findListByHref)).toBeObservable(cold('(a|)', {
           a: expected
         }));
       });
@@ -153,20 +153,20 @@ describe('BrowseService', () => {
     });
 
     describe('when findList is called with a valid browse definition id', () => {
-      it('should call hrefOnlyDataService.findAllByHref with the expected href', () => {
+      it('should call hrefOnlyDataService.findListByHref with the expected href', () => {
         const expected = browseDefinitions[1]._links.items.href + '?filterValue=' + encodeURIComponent(mockAuthorName);
 
         scheduler.schedule(() => service.getBrowseItemsFor(mockAuthorName, undefined, new BrowseEntrySearchOptions(browseDefinitions[1].id)).subscribe());
         scheduler.flush();
 
-        expect(getFirstUsedArgumentOfSpyMethod(hrefOnlyDataService.findAllByHref)).toBeObservable(cold('(a|)', {
+        expect(getFirstUsedArgumentOfSpyMethod(hrefOnlyDataService.findListByHref)).toBeObservable(cold('(a|)', {
           a: expected
         }));
       });
 
     });
     describe('when getBrowseItemsFor is called with a valid filter value and authority key', () => {
-      it('should call hrefOnlyDataService.findAllByHref with the expected href', () => {
+      it('should call hrefOnlyDataService.findListByHref with the expected href', () => {
         const expected = browseDefinitions[1]._links.items.href +
           '?filterValue=' + encodeURIComponent(mockAuthorName) +
           '&filterAuthority=' + encodeURIComponent(mockAuthorityKey);
@@ -174,7 +174,7 @@ describe('BrowseService', () => {
         scheduler.schedule(() => service.getBrowseItemsFor(mockAuthorName, mockAuthorityKey, new BrowseEntrySearchOptions(browseDefinitions[1].id)).subscribe());
         scheduler.flush();
 
-        expect(getFirstUsedArgumentOfSpyMethod(hrefOnlyDataService.findAllByHref)).toBeObservable(cold('(a|)', {
+        expect(getFirstUsedArgumentOfSpyMethod(hrefOnlyDataService.findListByHref)).toBeObservable(cold('(a|)', {
           a: expected
         }));
       });
@@ -267,11 +267,11 @@ describe('BrowseService', () => {
     describe('when getFirstItemFor is called with a valid browse definition id', () => {
       const expectedURL = browseDefinitions[1]._links.items.href + '?page=0&size=1';
 
-      it('should call hrefOnlyDataService.findAllByHref with the expected href', () => {
+      it('should call hrefOnlyDataService.findListByHref with the expected href', () => {
         scheduler.schedule(() => service.getFirstItemFor(browseDefinitions[1].id).subscribe());
         scheduler.flush();
 
-        expect(getFirstUsedArgumentOfSpyMethod(hrefOnlyDataService.findAllByHref)).toBeObservable(cold('(a|)', {
+        expect(getFirstUsedArgumentOfSpyMethod(hrefOnlyDataService.findListByHref)).toBeObservable(cold('(a|)', {
           a: expectedURL
         }));
       });

src/app/core/browse/browse.service.ts

@@ -96,7 +96,7 @@ export class BrowseService {
         return href;
       })
     );
-    return this.hrefOnlyDataService.findAllByHref<BrowseEntry>(href$);
+    return this.hrefOnlyDataService.findListByHref<BrowseEntry>(href$);
   }
 
   /**
@@ -141,7 +141,7 @@ export class BrowseService {
         return href;
       }),
     );
-    return this.hrefOnlyDataService.findAllByHref<Item>(href$);
+    return this.hrefOnlyDataService.findListByHref<Item>(href$);
   }
 
   /**
@@ -172,7 +172,7 @@ export class BrowseService {
       })
     );
 
-    return this.hrefOnlyDataService.findAllByHref<Item>(href$).pipe(
+    return this.hrefOnlyDataService.findListByHref<Item>(href$).pipe(
       getFirstSucceededRemoteData(),
       getFirstOccurrence()
     );
@@ -184,7 +184,7 @@ export class BrowseService {
    * @param items
    */
   getPrevBrowseItems(items: RemoteData<PaginatedList<Item>>): Observable<RemoteData<PaginatedList<Item>>> {
-    return this.hrefOnlyDataService.findAllByHref<Item>(items.payload.prev);
+    return this.hrefOnlyDataService.findListByHref<Item>(items.payload.prev);
   }
 
   /**
@@ -192,7 +192,7 @@ export class BrowseService {
    * @param items
    */
   getNextBrowseItems(items: RemoteData<PaginatedList<Item>>): Observable<RemoteData<PaginatedList<Item>>> {
-    return this.hrefOnlyDataService.findAllByHref<Item>(items.payload.next);
+    return this.hrefOnlyDataService.findListByHref<Item>(items.payload.next);
   }
 
   /**
@@ -200,7 +200,7 @@ export class BrowseService {
    * @param entries
    */
   getPrevBrowseEntries(entries: RemoteData<PaginatedList<BrowseEntry>>): Observable<RemoteData<PaginatedList<BrowseEntry>>> {
-    return this.hrefOnlyDataService.findAllByHref<BrowseEntry>(entries.payload.prev);
+    return this.hrefOnlyDataService.findListByHref<BrowseEntry>(entries.payload.prev);
   }
 
   /**
@@ -208,7 +208,7 @@ export class BrowseService {
    * @param entries
    */
   getNextBrowseEntries(entries: RemoteData<PaginatedList<BrowseEntry>>): Observable<RemoteData<PaginatedList<BrowseEntry>>> {
-    return this.hrefOnlyDataService.findAllByHref<BrowseEntry>(entries.payload.next);
+    return this.hrefOnlyDataService.findListByHref<BrowseEntry>(entries.payload.next);
   }
 
   /**

src/app/core/cache/builders/build-decorators.spec.ts

@@ -1,14 +1,7 @@
-/* eslint-disable max-classes-per-file */
 import { HALLink } from '../../shared/hal-link.model';
 import { HALResource } from '../../shared/hal-resource.model';
 import { ResourceType } from '../../shared/resource-type';
-import { dataService, getDataServiceFor, getLinkDefinition, link, } from './build-decorators';
+import { getLinkDefinition, link } from './build-decorators';
-
-class TestService {
-}
-
-class AnotherTestService {
-}
 
 class TestHALResource implements HALResource {
   _links: {
@@ -25,31 +18,6 @@ describe('build decorators', () => {
   beforeEach(() => {
     testType = new ResourceType('testType-' + new Date().getTime());
   });
-  describe('@dataService/getDataServiceFor', () => {
-
-    it('should register a resourcetype for a dataservice', () => {
-      dataService(testType)(TestService);
-      expect(getDataServiceFor(testType)).toBe(TestService);
-    });
-
-    describe(`when the resource type isn't specified`, () => {
-      it(`should throw an error`, () => {
-        expect(() => {
-          dataService(undefined)(TestService);
-        }).toThrow();
-      });
-    });
-
-    describe(`when there already is a registered dataservice for a resourcetype`, () => {
-      it(`should throw an error`, () => {
-        dataService(testType)(TestService);
-        expect(() => {
-          dataService(testType)(AnotherTestService);
-        }).toThrow();
-      });
-    });
-
-  });
 
   describe(`@link/getLinkDefinitions`, () => {
     it(`should register a link`, () => {

src/app/core/cache/builders/build-decorators.ts

@@ -3,20 +3,13 @@ import { hasNoValue, hasValue } from '../../../shared/empty.util';
 import { GenericConstructor } from '../../shared/generic-constructor';
 import { HALResource } from '../../shared/hal-resource.model';
 import { ResourceType } from '../../shared/resource-type';
-import {
+import { getResourceTypeValueFor } from '../object-cache.reducer';
-  getResourceTypeValueFor
-} from '../object-cache.reducer';
 import { InjectionToken } from '@angular/core';
-import { CacheableObject } from '../cacheable-object.model';
 import { TypedObject } from '../typed-object.model';
 
-export const DATA_SERVICE_FACTORY = new InjectionToken<(resourceType: ResourceType) => GenericConstructor<any>>('getDataServiceFor', {
-  providedIn: 'root',
-  factory: () => getDataServiceFor
-});
 export const LINK_DEFINITION_FACTORY = new InjectionToken<<T extends HALResource>(source: GenericConstructor<T>, linkName: keyof T['_links']) => LinkDefinition<T>>('getLinkDefinition', {
   providedIn: 'root',
-  factory: () => getLinkDefinition
+  factory: () => getLinkDefinition,
 });
 export const LINK_DEFINITION_MAP_FACTORY = new InjectionToken<<T extends HALResource>(source: GenericConstructor<T>) => Map<keyof T['_links'], LinkDefinition<T>>>('getLinkDefinitions', {
   providedIn: 'root',
@@ -27,7 +20,6 @@ const resolvedLinkKey = Symbol('resolvedLink');
 
 const resolvedLinkMap = new Map();
 const typeMap = new Map();
-const dataServiceMap = new Map();
 const linkMap = new Map();
 
 /**
@@ -46,39 +38,6 @@ export function getClassForType(type: string | ResourceType) {
   return typeMap.get(getResourceTypeValueFor(type));
 }
 
-/**
- * A class decorator to indicate that this class is a dataservice
- * for a given resource type.
- *
- * "dataservice" in this context means that it has findByHref and
- * findAllByHref methods.
- *
- * @param resourceType the resource type the class is a dataservice for
- */
-export function dataService(resourceType: ResourceType): any {
-  return (target: any) => {
-    if (hasNoValue(resourceType)) {
-      throw new Error(`Invalid @dataService annotation on ${target}, resourceType needs to be defined`);
-    }
-    const existingDataservice = dataServiceMap.get(resourceType.value);
-
-    if (hasValue(existingDataservice)) {
-      throw new Error(`Multiple dataservices for ${resourceType.value}: ${existingDataservice} and ${target}`);
-    }
-
-    dataServiceMap.set(resourceType.value, target);
-  };
-}
-
-/**
- * Return the dataservice matching the given resource type
- *
- * @param resourceType the resource type you want the matching dataservice for
- */
-export function getDataServiceFor<T extends CacheableObject>(resourceType: ResourceType) {
-  return dataServiceMap.get(resourceType.value);
-}
-
 /**
  * A class to represent the data that can be set by the @link decorator
  */

src/app/core/cache/builders/link.service.spec.ts

@@ -6,9 +6,10 @@ import { HALLink } from '../../shared/hal-link.model';
 import { HALResource } from '../../shared/hal-resource.model';
 import { ResourceType } from '../../shared/resource-type';
 import { LinkService } from './link.service';
-import { DATA_SERVICE_FACTORY, LINK_DEFINITION_FACTORY, LINK_DEFINITION_MAP_FACTORY } from './build-decorators';
+import { LINK_DEFINITION_FACTORY, LINK_DEFINITION_MAP_FACTORY } from './build-decorators';
 import { isEmpty } from 'rxjs/operators';
 import { FindListOptions } from '../../data/find-list-options.model';
+import { DATA_SERVICE_FACTORY } from '../../data/base/data-service.decorator';
 
 const TEST_MODEL = new ResourceType('testmodel');
 let result: any;
@@ -32,8 +33,8 @@ class TestModel implements HALResource {
 
 @Injectable()
 class TestDataService {
-  findAllByHref(href: string, findListOptions: FindListOptions = {}, useCachedVersionIfAvailable = true, reRequestOnStale = true, ...linksToFollow: FollowLinkConfig<any>[]) {
+  findListByHref(href: string, findListOptions: FindListOptions = {}, useCachedVersionIfAvailable = true, reRequestOnStale = true, ...linksToFollow: FollowLinkConfig<any>[]) {
-    return 'findAllByHref';
+    return 'findListByHref';
   }
 
   findByHref(href: string, useCachedVersionIfAvailable = true, reRequestOnStale = true, ...linksToFollow: FollowLinkConfig<any>[]) {
@@ -64,7 +65,7 @@ describe('LinkService', () => {
       }
     });
     testDataService = new TestDataService();
-    spyOn(testDataService, 'findAllByHref').and.callThrough();
+    spyOn(testDataService, 'findListByHref').and.callThrough();
     spyOn(testDataService, 'findByHref').and.callThrough();
     TestBed.configureTestingModule({
       providers: [LinkService, {
@@ -118,8 +119,8 @@ describe('LinkService', () => {
         });
         service.resolveLink(testModel, followLink('predecessor', { findListOptions: { some: 'options ' } as any }, followLink('successor')));
       });
-      it('should call dataservice.findAllByHref with the correct href, findListOptions,  and nested links', () => {
+      it('should call dataservice.findListByHref with the correct href, findListOptions,  and nested links', () => {
-        expect(testDataService.findAllByHref).toHaveBeenCalledWith(testModel._links.predecessor.href, { some: 'options ' } as any, true, true, followLink('successor'));
+        expect(testDataService.findListByHref).toHaveBeenCalledWith(testModel._links.predecessor.href, { some: 'options ' } as any, true, true, followLink('successor'));
       });
     });
     describe('either way', () => {

src/app/core/cache/builders/link.service.ts

@@ -3,28 +3,30 @@ import { hasNoValue, hasValue, isNotEmpty } from '../../../shared/empty.util';
 import { FollowLinkConfig } from '../../../shared/utils/follow-link-config.model';
 import { GenericConstructor } from '../../shared/generic-constructor';
 import { HALResource } from '../../shared/hal-resource.model';
+import { DATA_SERVICE_FACTORY } from '../../data/base/data-service.decorator';
 import {
-  DATA_SERVICE_FACTORY,
   LINK_DEFINITION_FACTORY,
   LINK_DEFINITION_MAP_FACTORY,
-  LinkDefinition
+  LinkDefinition,
 } from './build-decorators';
 import { RemoteData } from '../../data/remote-data';
 import { EMPTY, Observable } from 'rxjs';
 import { ResourceType } from '../../shared/resource-type';
+import { HALDataService } from '../../data/base/hal-data-service.interface';
+import { PaginatedList } from '../../data/paginated-list.model';
 
 /**
  * A Service to handle the resolving and removing
  * of resolved {@link HALLink}s on HALResources
  */
 @Injectable({
-  providedIn: 'root'
+  providedIn: 'root',
 })
 export class LinkService {
 
   constructor(
     protected parentInjector: Injector,
-    @Inject(DATA_SERVICE_FACTORY) private getDataServiceFor: (resourceType: ResourceType) => GenericConstructor<any>,
+    @Inject(DATA_SERVICE_FACTORY) private getDataServiceFor: (resourceType: ResourceType) => GenericConstructor<HALDataService<any>>,
     @Inject(LINK_DEFINITION_FACTORY) private getLinkDefinition: <T extends HALResource>(source: GenericConstructor<T>, linkName: keyof T['_links']) => LinkDefinition<T>,
     @Inject(LINK_DEFINITION_MAP_FACTORY) private getLinkDefinitions: <T extends HALResource>(source: GenericConstructor<T>) => Map<keyof T['_links'], LinkDefinition<T>>,
   ) {
@@ -51,7 +53,7 @@ export class LinkService {
    * @param model the {@link HALResource} to resolve the link for
    * @param linkToFollow the {@link FollowLinkConfig} to resolve
    */
-  public resolveLinkWithoutAttaching<T extends HALResource, U extends HALResource>(model, linkToFollow: FollowLinkConfig<T>): Observable<RemoteData<U>> {
+  public resolveLinkWithoutAttaching<T extends HALResource, U extends HALResource>(model, linkToFollow: FollowLinkConfig<T>): Observable<RemoteData<U | PaginatedList<U>>> {
     const matchingLinkDef = this.getLinkDefinition(model.constructor, linkToFollow.name);
 
     if (hasValue(matchingLinkDef)) {
@@ -61,9 +63,9 @@ export class LinkService {
         throw new Error(`The @link() for ${linkToFollow.name} on ${model.constructor.name} models uses the resource type ${matchingLinkDef.resourceType.value.toUpperCase()}, but there is no service with an @dataService(${matchingLinkDef.resourceType.value.toUpperCase()}) annotation in order to retrieve it`);
       }
 
-      const service = Injector.create({
+      const service: HALDataService<any> = Injector.create({
         providers: [],
-        parent: this.parentInjector
+        parent: this.parentInjector,
       }).get(provider);
 
       const link = model._links[matchingLinkDef.linkName];
@@ -72,7 +74,7 @@ export class LinkService {
 
         try {
           if (matchingLinkDef.isList) {
-            return service.findAllByHref(href, linkToFollow.findListOptions, linkToFollow.useCachedVersionIfAvailable, linkToFollow.reRequestOnStale, ...linkToFollow.linksToFollow);
+            return service.findListByHref(href, linkToFollow.findListOptions, linkToFollow.useCachedVersionIfAvailable, linkToFollow.reRequestOnStale, ...linkToFollow.linksToFollow);
           } else {
             return service.findByHref(href, linkToFollow.useCachedVersionIfAvailable, linkToFollow.reRequestOnStale, ...linkToFollow.linksToFollow);
           }

src/app/core/config/config-data.service.spec.ts

@@ -1,7 +1,7 @@
 import { getTestScheduler } from 'jasmine-marbles';
 import { TestScheduler } from 'rxjs/testing';
 import { getMockRequestService } from '../../shared/mocks/request.service.mock';
-import { ConfigService } from './config.service';
+import { ConfigDataService } from './config-data.service';
 import { RequestService } from '../data/request.service';
 import { GetRequest } from '../data/request.models';
 import { HALEndpointService } from '../shared/hal-endpoint.service';
@@ -9,23 +9,26 @@ import { HALEndpointServiceStub } from '../../shared/testing/hal-endpoint-servic
 import { RemoteDataBuildService } from '../cache/builders/remote-data-build.service';
 import { getMockRemoteDataBuildService } from '../../shared/mocks/remote-data-build.service.mock';
 import { FindListOptions } from '../data/find-list-options.model';
+import { ObjectCacheService } from '../cache/object-cache.service';
 
 const LINK_NAME = 'test';
 const BROWSE = 'search/findByCollection';
 
-class TestService extends ConfigService {
+class TestService extends ConfigDataService {
   protected linkPath = LINK_NAME;
   protected browseEndpoint = BROWSE;
 
   constructor(
     protected requestService: RequestService,
     protected rdbService: RemoteDataBuildService,
-    protected halService: HALEndpointService) {
+    protected objectCache: ObjectCacheService,
-    super(requestService, rdbService, null, null, halService, null, null, null, BROWSE);
+    protected halService: HALEndpointService,
+  ) {
+    super(BROWSE, requestService, rdbService, objectCache, halService);
   }
 }
 
-describe('ConfigService', () => {
+describe('ConfigDataService', () => {
   let scheduler: TestScheduler;
   let service: TestService;
   let requestService: RequestService;
@@ -45,7 +48,8 @@ describe('ConfigService', () => {
     return new TestService(
       requestService,
       rdbService,
-      halService
+      null,
+      halService,
     );
   }
 

src/app/core/config/config-data.service.ts

@@ -0,0 +1,40 @@
+import { Observable } from 'rxjs';
+import { ConfigObject } from './models/config.model';
+import { RemoteData } from '../data/remote-data';
+import { FollowLinkConfig } from '../../shared/utils/follow-link-config.model';
+import { getFirstCompletedRemoteData } from '../shared/operators';
+import { map } from 'rxjs/operators';
+import { BaseDataService } from '../data/base/base-data.service';
+
+/**
+ * Abstract data service to retrieve configuration objects from the REST server.
+ * Common logic for configuration objects should be implemented here.
+ */
+export abstract class ConfigDataService extends BaseDataService<ConfigObject> {
+  /**
+   * Returns an observable of {@link RemoteData} of an object, based on an href, with a list of
+   * {@link FollowLinkConfig}, to automatically resolve {@link HALLink}s of the object
+   *
+   * Throws an error if a configuration object cannot be retrieved.
+   *
+   * @param href                        The url of object we want to retrieve
+   * @param useCachedVersionIfAvailable If this is true, the request will only be sent if there's
+   *                                    no valid cached version. Defaults to true
+   * @param reRequestOnStale            Whether or not the request should automatically be re-
+   *                                    requested after the response becomes stale
+   * @param linksToFollow               List of {@link FollowLinkConfig} that indicate which
+   *                                    {@link HALLink}s should be automatically resolved
+   */
+  public findByHref(href: string, useCachedVersionIfAvailable = true, reRequestOnStale = true, ...linksToFollow: FollowLinkConfig<ConfigObject>[]): Observable<RemoteData<ConfigObject>> {
+    return super.findByHref(href, useCachedVersionIfAvailable, reRequestOnStale, ...linksToFollow).pipe(
+      getFirstCompletedRemoteData(),
+      map((rd: RemoteData<ConfigObject>) => {
+        if (rd.hasFailed) {
+          throw new Error(`Couldn't retrieve the config`);
+        } else {
+          return rd;
+        }
+      }),
+    );
+  }
+}

src/app/core/config/config.service.ts

@@ -1,67 +0,0 @@
-/* eslint-disable max-classes-per-file */
-import { Observable } from 'rxjs';
-import { RequestService } from '../data/request.service';
-import { HALEndpointService } from '../shared/hal-endpoint.service';
-import { RemoteDataBuildService } from '../cache/builders/remote-data-build.service';
-import { ConfigObject } from './models/config.model';
-import { RemoteData } from '../data/remote-data';
-import { DataService } from '../data/data.service';
-import { Store } from '@ngrx/store';
-import { ObjectCacheService } from '../cache/object-cache.service';
-import { NotificationsService } from '../../shared/notifications/notifications.service';
-import { HttpClient } from '@angular/common/http';
-import { DefaultChangeAnalyzer } from '../data/default-change-analyzer.service';
-import { FollowLinkConfig } from '../../shared/utils/follow-link-config.model';
-import { getFirstCompletedRemoteData } from '../shared/operators';
-import { map } from 'rxjs/operators';
-import { CoreState } from '../core-state.model';
-
-class DataServiceImpl extends DataService<ConfigObject> {
-  constructor(
-    protected requestService: RequestService,
-    protected rdbService: RemoteDataBuildService,
-    protected store: Store<CoreState>,
-    protected objectCache: ObjectCacheService,
-    protected halService: HALEndpointService,
-    protected notificationsService: NotificationsService,
-    protected http: HttpClient,
-    protected comparator: DefaultChangeAnalyzer<ConfigObject>,
-    protected linkPath: string
-  ) {
-    super();
-  }
-}
-
-export abstract class ConfigService {
-  /**
-   * A private DataService instance to delegate specific methods to.
-   */
-  private dataService: DataServiceImpl;
-
-  constructor(
-    protected requestService: RequestService,
-    protected rdbService: RemoteDataBuildService,
-    protected store: Store<CoreState>,
-    protected objectCache: ObjectCacheService,
-    protected halService: HALEndpointService,
-    protected notificationsService: NotificationsService,
-    protected http: HttpClient,
-    protected comparator: DefaultChangeAnalyzer<ConfigObject>,
-    protected linkPath: string
-  ) {
-    this.dataService = new DataServiceImpl(requestService, rdbService, null, objectCache, halService, notificationsService, http, comparator, this.linkPath);
-  }
-
-  public findByHref(href: string, useCachedVersionIfAvailable = true, reRequestOnStale = true, ...linksToFollow: FollowLinkConfig<ConfigObject>[]): Observable<RemoteData<ConfigObject>> {
-    return this.dataService.findByHref(href, useCachedVersionIfAvailable, reRequestOnStale, ...linksToFollow).pipe(
-      getFirstCompletedRemoteData(),
-      map((rd: RemoteData<ConfigObject>) => {
-        if (rd.hasFailed) {
-          throw new Error(`Couldn't retrieve the config`);
-        } else {
-          return rd;
-        }
-      })
-    );
-  }
-}

src/app/core/config/submission-accesses-config-data.service.ts

@@ -1,41 +1,46 @@
 import { Injectable } from '@angular/core';
-import { ConfigService } from './config.service';
+import { ConfigDataService } from './config-data.service';
 import { RequestService } from '../data/request.service';
 import { HALEndpointService } from '../shared/hal-endpoint.service';
 import { ObjectCacheService } from '../cache/object-cache.service';
-import { dataService } from '../cache/builders/build-decorators';
 import { SUBMISSION_ACCESSES_TYPE } from './models/config-type';
 import { RemoteDataBuildService } from '../cache/builders/remote-data-build.service';
-import { Store } from '@ngrx/store';
-import { NotificationsService } from '../../shared/notifications/notifications.service';
-import { HttpClient } from '@angular/common/http';
-import { DefaultChangeAnalyzer } from '../data/default-change-analyzer.service';
 import { ConfigObject } from './models/config.model';
 import { SubmissionAccessesModel } from './models/config-submission-accesses.model';
 import { RemoteData } from '../data/remote-data';
 import { Observable } from 'rxjs';
 import { FollowLinkConfig } from '../../shared/utils/follow-link-config.model';
-import { CoreState } from '../core-state.model';
+import { dataService } from '../data/base/data-service.decorator';
 
 /**
  * Provides methods to retrieve, from REST server, bitstream access conditions configurations applicable during the submission process.
  */
 @Injectable()
 @dataService(SUBMISSION_ACCESSES_TYPE)
-export class SubmissionAccessesConfigService extends ConfigService {
+export class SubmissionAccessesConfigDataService extends ConfigDataService {
   constructor(
     protected requestService: RequestService,
     protected rdbService: RemoteDataBuildService,
-    protected store: Store<CoreState>,
     protected objectCache: ObjectCacheService,
     protected halService: HALEndpointService,
-    protected notificationsService: NotificationsService,
-    protected http: HttpClient,
-    protected comparator: DefaultChangeAnalyzer<SubmissionAccessesModel>
   ) {
-    super(requestService, rdbService, null, objectCache, halService, notificationsService, http, comparator, 'submissionaccessoptions');
+    super('submissionaccessoptions', requestService, rdbService, objectCache, halService);
   }
 
+  /**
+   * Returns an observable of {@link RemoteData} of an object, based on an href, with a list of
+   * {@link FollowLinkConfig}, to automatically resolve {@link HALLink}s of the object
+   *
+   * Throws an error if a configuration object cannot be retrieved.
+   *
+   * @param href                        The url of object we want to retrieve
+   * @param useCachedVersionIfAvailable If this is true, the request will only be sent if there's
+   *                                    no valid cached version. Defaults to true
+   * @param reRequestOnStale            Whether or not the request should automatically be re-
+   *                                    requested after the response becomes stale
+   * @param linksToFollow               List of {@link FollowLinkConfig} that indicate which
+   *                                    {@link HALLink}s should be automatically resolved
+   */
   findByHref(href: string, useCachedVersionIfAvailable = true, reRequestOnStale = true, ...linksToFollow): Observable<RemoteData<SubmissionAccessesModel>> {
     return super.findByHref(href, useCachedVersionIfAvailable, reRequestOnStale, ...linksToFollow as FollowLinkConfig<ConfigObject>[]) as Observable<RemoteData<SubmissionAccessesModel>>;
   }

src/app/core/config/submission-forms-config-data.service.ts

@@ -1,39 +1,46 @@
 import { Injectable } from '@angular/core';
-
+import { ConfigDataService } from './config-data.service';
-import { ConfigService } from './config.service';
 import { RequestService } from '../data/request.service';
 import { HALEndpointService } from '../shared/hal-endpoint.service';
 import { RemoteDataBuildService } from '../cache/builders/remote-data-build.service';
-import { Store } from '@ngrx/store';
 import { ObjectCacheService } from '../cache/object-cache.service';
-import { NotificationsService } from '../../shared/notifications/notifications.service';
-import { HttpClient } from '@angular/common/http';
-import { DefaultChangeAnalyzer } from '../data/default-change-analyzer.service';
 import { ConfigObject } from './models/config.model';
-import { dataService } from '../cache/builders/build-decorators';
 import { SUBMISSION_FORMS_TYPE } from './models/config-type';
 import { SubmissionFormsModel } from './models/config-submission-forms.model';
 import { RemoteData } from '../data/remote-data';
 import { Observable } from 'rxjs';
 import { FollowLinkConfig } from '../../shared/utils/follow-link-config.model';
-import { CoreState } from '../core-state.model';
+import { dataService } from '../data/base/data-service.decorator';
 
+/**
+ * Data service to retrieve submission form configuration objects from the REST server.
+ */
 @Injectable()
 @dataService(SUBMISSION_FORMS_TYPE)
-export class SubmissionFormsConfigService extends ConfigService {
+export class SubmissionFormsConfigDataService extends ConfigDataService {
   constructor(
     protected requestService: RequestService,
     protected rdbService: RemoteDataBuildService,
-    protected store: Store<CoreState>,
     protected objectCache: ObjectCacheService,
     protected halService: HALEndpointService,
-    protected notificationsService: NotificationsService,
-    protected http: HttpClient,
-    protected comparator: DefaultChangeAnalyzer<SubmissionFormsModel>
   ) {
-    super(requestService, rdbService, null, objectCache, halService, notificationsService, http, comparator, 'submissionforms');
+    super('submissionforms', requestService, rdbService, objectCache, halService);
   }
 
+  /**
+   * Returns an observable of {@link RemoteData} of an object, based on an href, with a list of
+   * {@link FollowLinkConfig}, to automatically resolve {@link HALLink}s of the object
+   *
+   * Throws an error if a configuration object cannot be retrieved.
+   *
+   * @param href                        The url of object we want to retrieve
+   * @param useCachedVersionIfAvailable If this is true, the request will only be sent if there's
+   *                                    no valid cached version. Defaults to true
+   * @param reRequestOnStale            Whether or not the request should automatically be re-
+   *                                    requested after the response becomes stale
+   * @param linksToFollow               List of {@link FollowLinkConfig} that indicate which
+   *                                    {@link HALLink}s should be automatically resolved
+   */
   public findByHref(href: string, useCachedVersionIfAvailable = true, reRequestOnStale = true, ...linksToFollow: FollowLinkConfig<SubmissionFormsModel>[]): Observable<RemoteData<SubmissionFormsModel>> {
     return super.findByHref(href, useCachedVersionIfAvailable, reRequestOnStale, ...linksToFollow as FollowLinkConfig<ConfigObject>[]) as Observable<RemoteData<SubmissionFormsModel>>;
   }

src/app/core/config/submission-uploads-config-data.service.ts

@@ -1,39 +1,30 @@
 import { Injectable } from '@angular/core';
-import { ConfigService } from './config.service';
+import { ConfigDataService } from './config-data.service';
 import { RequestService } from '../data/request.service';
 import { HALEndpointService } from '../shared/hal-endpoint.service';
 import { ObjectCacheService } from '../cache/object-cache.service';
-import { dataService } from '../cache/builders/build-decorators';
 import { SUBMISSION_UPLOADS_TYPE } from './models/config-type';
 import { RemoteDataBuildService } from '../cache/builders/remote-data-build.service';
-import { Store } from '@ngrx/store';
-import { NotificationsService } from '../../shared/notifications/notifications.service';
-import { HttpClient } from '@angular/common/http';
-import { DefaultChangeAnalyzer } from '../data/default-change-analyzer.service';
 import { ConfigObject } from './models/config.model';
 import { SubmissionUploadsModel } from './models/config-submission-uploads.model';
 import { RemoteData } from '../data/remote-data';
 import { Observable } from 'rxjs';
 import { FollowLinkConfig } from '../../shared/utils/follow-link-config.model';
-import { CoreState } from '../core-state.model';
+import { dataService } from '../data/base/data-service.decorator';
 
 /**
  * Provides methods to retrieve, from REST server, bitstream access conditions configurations applicable during the submission process.
  */
 @Injectable()
 @dataService(SUBMISSION_UPLOADS_TYPE)
-export class SubmissionUploadsConfigService extends ConfigService {
+export class SubmissionUploadsConfigDataService extends ConfigDataService {
   constructor(
     protected requestService: RequestService,
     protected rdbService: RemoteDataBuildService,
-    protected store: Store<CoreState>,
     protected objectCache: ObjectCacheService,
     protected halService: HALEndpointService,
-    protected notificationsService: NotificationsService,
-    protected http: HttpClient,
-    protected comparator: DefaultChangeAnalyzer<SubmissionUploadsModel>
   ) {
-    super(requestService, rdbService, null, objectCache, halService, notificationsService, http, comparator, 'submissionuploads');
+    super('submissionuploads', requestService, rdbService, objectCache, halService);
   }
 
   findByHref(href: string, useCachedVersionIfAvailable = true, reRequestOnStale = true, ...linksToFollow): Observable<RemoteData<SubmissionUploadsModel>> {

src/app/core/core.module.ts

@@ -36,7 +36,7 @@ import { SubmissionDefinitionsModel } from './config/models/config-submission-de
 import { SubmissionFormsModel } from './config/models/config-submission-forms.model';
 import { SubmissionSectionModel } from './config/models/config-submission-section.model';
 import { SubmissionUploadsModel } from './config/models/config-submission-uploads.model';
-import { SubmissionFormsConfigService } from './config/submission-forms-config.service';
+import { SubmissionFormsConfigDataService } from './config/submission-forms-config-data.service';
 import { coreEffects } from './core.effects';
 import { coreReducers } from './core.reducers';
 import { BitstreamFormatDataService } from './data/bitstream-format-data.service';
@@ -49,8 +49,8 @@ import { DSOChangeAnalyzer } from './data/dso-change-analyzer.service';
 import { DSOResponseParsingService } from './data/dso-response-parsing.service';
 import { DSpaceObjectDataService } from './data/dspace-object-data.service';
 import { EndpointMapResponseParsingService } from './data/endpoint-map-response-parsing.service';
-import { EntityTypeService } from './data/entity-type.service';
+import { EntityTypeDataService } from './data/entity-type-data.service';
-import { ExternalSourceService } from './data/external-source.service';
+import { ExternalSourceDataService } from './data/external-source-data.service';
 import { FacetConfigResponseParsingService } from './data/facet-config-response-parsing.service';
 import { FacetValueResponseParsingService } from './data/facet-value-response-parsing.service';
 import { FilteredDiscoveryPageResponseParsingService } from './data/filtered-discovery-page-response-parsing.service';
@@ -58,9 +58,9 @@ import { ItemDataService } from './data/item-data.service';
 import { LookupRelationService } from './data/lookup-relation.service';
 import { MyDSpaceResponseParsingService } from './data/mydspace-response-parsing.service';
 import { ObjectUpdatesService } from './data/object-updates/object-updates.service';
-import { RelationshipTypeService } from './data/relationship-type.service';
+import { RelationshipTypeDataService } from './data/relationship-type-data.service';
-import { RelationshipService } from './data/relationship.service';
+import { RelationshipDataService } from './data/relationship-data.service';
-import { ResourcePolicyService } from './resource-policy/resource-policy.service';
+import { ResourcePolicyDataService } from './resource-policy/resource-policy-data.service';
 import { SearchResponseParsingService } from './data/search-response-parsing.service';
 import { SiteDataService } from './data/site-data.service';
 import { DspaceRestService } from './dspace-rest/dspace-rest.service';
@@ -170,14 +170,16 @@ import { SubmissionAccessesModel } from './config/models/config-submission-acces
 import { AccessStatusObject } from '../shared/object-list/access-status-badge/access-status.model';
 import { AccessStatusDataService } from './data/access-status-data.service';
 import { LinkHeadService } from './services/link-head.service';
-import { ResearcherProfileService } from './profile/researcher-profile.service';
+import { ResearcherProfileDataService } from './profile/researcher-profile-data.service';
 import { ProfileClaimService } from '../profile-page/profile-claim/profile-claim.service';
 import { ResearcherProfile } from './profile/model/researcher-profile.model';
-import { OrcidQueueService } from './orcid/orcid-queue.service';
+import { OrcidQueueDataService } from './orcid/orcid-queue-data.service';
 import { OrcidHistoryDataService } from './orcid/orcid-history-data.service';
 import { OrcidQueue } from './orcid/model/orcid-queue.model';
 import { OrcidHistory } from './orcid/model/orcid-history.model';
 import { OrcidAuthService } from './orcid/orcid-auth.service';
+import { VocabularyDataService } from './submission/vocabularies/vocabulary.data.service';
+import { VocabularyEntryDetailsDataService } from './submission/vocabularies/vocabulary-entry-details.data.service';
 
 /**
  * When not in production, endpoint responses can be mocked for testing purposes
@@ -223,7 +225,7 @@ const PROVIDERS = [
   MetadataService,
   ObjectCacheService,
   PaginationComponentOptions,
-  ResourcePolicyService,
+  ResourcePolicyDataService,
   RegistryService,
   BitstreamFormatDataService,
   RemoteDataBuildService,
@@ -238,7 +240,7 @@ const PROVIDERS = [
   AccessStatusDataService,
   SubmissionCcLicenseDataService,
   SubmissionCcLicenseUrlDataService,
-  SubmissionFormsConfigService,
+  SubmissionFormsConfigDataService,
   SubmissionRestService,
   SubmissionResponseParsingService,
   SubmissionJsonPatchOperationsService,
@@ -259,7 +261,7 @@ const PROVIDERS = [
   MenuService,
   ObjectUpdatesService,
   SearchService,
-  RelationshipService,
+  RelationshipDataService,
   MyDSpaceGuard,
   RoleService,
   TaskResponseParsingService,
@@ -267,7 +269,7 @@ const PROVIDERS = [
   PoolTaskDataService,
   BitstreamDataService,
   DsDynamicTypeBindRelationService,
-  EntityTypeService,
+  EntityTypeDataService,
   ContentSourceResponseParsingService,
   ItemTemplateDataService,
   SearchService,
@@ -276,8 +278,8 @@ const PROVIDERS = [
   SearchFilterService,
   SearchConfigurationService,
   SelectableListService,
-  RelationshipTypeService,
+  RelationshipTypeDataService,
-  ExternalSourceService,
+  ExternalSourceDataService,
   LookupRelationService,
   VersionDataService,
   VersionHistoryDataService,
@@ -300,14 +302,16 @@ const PROVIDERS = [
   FilteredDiscoveryPageResponseParsingService,
   { provide: NativeWindowService, useFactory: NativeWindowFactory },
   VocabularyService,
+  VocabularyDataService,
+  VocabularyEntryDetailsDataService,
   VocabularyTreeviewService,
   SequenceService,
   GroupDataService,
   FeedbackDataService,
-  ResearcherProfileService,
+  ResearcherProfileDataService,
   ProfileClaimService,
   OrcidAuthService,
-  OrcidQueueService,
+  OrcidQueueDataService,
   OrcidHistoryDataService,
 ];
 

src/app/core/data/access-status-data.service.spec.ts

@@ -76,6 +76,6 @@ describe('AccessStatusDataService', () => {
     });
     halService = new HALEndpointServiceStub(url);
     notificationsService = new NotificationsServiceStub();
-    service = new AccessStatusDataService(null, halService, null, notificationsService, objectCache, rdbService, requestService, null);
+    service = new AccessStatusDataService(requestService, rdbService, objectCache, halService);
   }
 });

src/app/core/data/access-status-data.service.ts

@@ -1,38 +1,30 @@
-import { HttpClient } from '@angular/common/http';
 import { Injectable } from '@angular/core';
-import { Store } from '@ngrx/store';
-import { NotificationsService } from '../../shared/notifications/notifications.service';
-import { dataService } from '../cache/builders/build-decorators';
 import { RemoteDataBuildService } from '../cache/builders/remote-data-build.service';
 import { ObjectCacheService } from '../cache/object-cache.service';
 import { HALEndpointService } from '../shared/hal-endpoint.service';
-import { DataService } from './data.service';
 import { RequestService } from './request.service';
-import { DefaultChangeAnalyzer } from './default-change-analyzer.service';
-import { CoreState } from '../core-state.model';
 import { AccessStatusObject } from 'src/app/shared/object-list/access-status-badge/access-status.model';
 import { ACCESS_STATUS } from 'src/app/shared/object-list/access-status-badge/access-status.resource-type';
 import { Observable } from 'rxjs';
 import { RemoteData } from './remote-data';
 import { Item } from '../shared/item.model';
+import { BaseDataService } from './base/base-data.service';
+import { dataService } from './base/data-service.decorator';
 
+/**
+ * Data service responsible for retrieving the access status of Items
+ */
 @Injectable()
 @dataService(ACCESS_STATUS)
-export class AccessStatusDataService extends DataService<AccessStatusObject> {
+export class AccessStatusDataService extends BaseDataService<AccessStatusObject> {
-
-  protected linkPath = 'accessStatus';
 
   constructor(
-    protected comparator: DefaultChangeAnalyzer<AccessStatusObject>,
-    protected halService: HALEndpointService,
-    protected http: HttpClient,
-    protected notificationsService: NotificationsService,
-    protected objectCache: ObjectCacheService,
-    protected rdbService: RemoteDataBuildService,
     protected requestService: RequestService,
-    protected store: Store<CoreState>,
+    protected rdbService: RemoteDataBuildService,
+    protected objectCache: ObjectCacheService,
+    protected halService: HALEndpointService,
   ) {
-    super();
+    super('accessStatus', requestService, rdbService, objectCache, halService);
   }
 
   /**

src/app/core/data/base/base-data.service.spec.ts

@@ -1,54 +1,38 @@
-/* eslint-disable max-classes-per-file */
+/**
-import { HttpClient } from '@angular/common/http';
+ * The contents of this file are subject to the license and copyright
-import { Store } from '@ngrx/store';
+ * detailed in the LICENSE and NOTICE files at the root of the source
-import { compare, Operation } from 'fast-json-patch';
+ * tree and available online at
+ *
+ * http://www.dspace.org/license/
+ */
+import { RequestService } from '../request.service';
+import { RemoteDataBuildService } from '../../cache/builders/remote-data-build.service';
+import { HALEndpointService } from '../../shared/hal-endpoint.service';
+import { ObjectCacheService } from '../../cache/object-cache.service';
+import { FindListOptions } from '../find-list-options.model';
 import { Observable, of as observableOf } from 'rxjs';
-import { NotificationsService } from '../../shared/notifications/notifications.service';
+import { getMockRequestService } from '../../../shared/mocks/request.service.mock';
-import { followLink } from '../../shared/utils/follow-link-config.model';
+import { HALEndpointServiceStub } from '../../../shared/testing/hal-endpoint-service.stub';
-import { RemoteDataBuildService } from '../cache/builders/remote-data-build.service';
+import { getMockRemoteDataBuildService } from '../../../shared/mocks/remote-data-build.service.mock';
-import { SortDirection, SortOptions } from '../cache/models/sort-options.model';
+import { followLink } from '../../../shared/utils/follow-link-config.model';
-import { ObjectCacheService } from '../cache/object-cache.service';
-import { DSpaceObject } from '../shared/dspace-object.model';
-import { HALEndpointService } from '../shared/hal-endpoint.service';
-import { Item } from '../shared/item.model';
-import {
-  createFailedRemoteDataObject,
-  createSuccessfulRemoteDataObject,
-  createSuccessfulRemoteDataObject$,
-} from '../../shared/remote-data.utils';
-import { ChangeAnalyzer } from './change-analyzer';
-import { DataService } from './data.service';
-import { PatchRequest } from './request.models';
-import { RequestService } from './request.service';
-import { getMockRequestService } from '../../shared/mocks/request.service.mock';
-import { HALEndpointServiceStub } from '../../shared/testing/hal-endpoint-service.stub';
-import { RequestParam } from '../cache/models/request-param.model';
-import { getMockRemoteDataBuildService } from '../../shared/mocks/remote-data-build.service.mock';
 import { TestScheduler } from 'rxjs/testing';
-import { RemoteData } from './remote-data';
+import { RemoteData } from '../remote-data';
-import { RequestEntryState } from './request-entry-state.model';
+import { RequestEntryState } from '../request-entry-state.model';
-import { CoreState } from '../core-state.model';
-import { FindListOptions } from './find-list-options.model';
 import { fakeAsync, tick } from '@angular/core/testing';
+import { BaseDataService } from './base-data.service';
 
 const endpoint = 'https://rest.api/core';
 
 const BOOLEAN = { f: false, t: true };
 
-class TestService extends DataService<any> {
+class TestService extends BaseDataService<any> {
-
   constructor(
     protected requestService: RequestService,
     protected rdbService: RemoteDataBuildService,
-    protected store: Store<CoreState>,
-    protected linkPath: string,
-    protected halService: HALEndpointService,
     protected objectCache: ObjectCacheService,
-    protected notificationsService: NotificationsService,
+    protected halService: HALEndpointService,
-    protected http: HttpClient,
-    protected comparator: ChangeAnalyzer<Item>
   ) {
-    super();
+    super(undefined, requestService, rdbService, objectCache, halService);
   }
 
   public getBrowseEndpoint(options: FindListOptions = {}, linkPath: string = this.linkPath): Observable<string> {
@@ -56,24 +40,12 @@ class TestService extends DataService<any> {
   }
 }
 
-class DummyChangeAnalyzer implements ChangeAnalyzer<Item> {
+describe('BaseDataService', () => {
-  diff(object1: Item, object2: Item): Operation[] {
-    return compare((object1 as any).metadata, (object2 as any).metadata);
-  }
-
-}
-
-describe('DataService', () => {
   let service: TestService;
-  let options: FindListOptions;
   let requestService;
   let halService;
   let rdbService;
-  let notificationsService;
-  let http;
-  let comparator;
   let objectCache;
-  let store;
   let selfLink;
   let linksToFollow;
   let testScheduler;
@@ -83,9 +55,6 @@ describe('DataService', () => {
     requestService = getMockRequestService();
     halService = new HALEndpointServiceStub('url') as any;
     rdbService = getMockRemoteDataBuildService();
-    notificationsService = {} as NotificationsService;
-    http = {} as HttpClient;
-    comparator = new DummyChangeAnalyzer() as any;
     objectCache = {
 
       addPatch: () => {
@@ -98,7 +67,6 @@ describe('DataService', () => {
         /* empty */
       }
     } as any;
-    store = {} as Store<CoreState>;
     selfLink = 'https://rest.api/endpoint/1698f1d3-be98-4c51-9fd8-6bfedcbd59b7';
     linksToFollow = [
       followLink('a'),
@@ -126,17 +94,11 @@ describe('DataService', () => {
       ErrorStale: new RemoteData(timeStamp, msToLive, timeStamp, RequestEntryState.ErrorStale, errorMessage, undefined, statusCodeError),
     };
 
-
     return new TestService(
       requestService,
       rdbService,
-      store,
-      endpoint,
-      halService,
       objectCache,
-      notificationsService,
+      halService,
-      http,
-      comparator,
     );
   }
 
@@ -144,259 +106,6 @@ describe('DataService', () => {
     service = initTestService();
   });
 
-  describe('getFindAllHref', () => {
-
-    it('should return an observable with the endpoint', () => {
-      options = {};
-
-      (service as any).getFindAllHref(options).subscribe((value) => {
-          expect(value).toBe(endpoint);
-        }
-      );
-    });
-
-    it('should include page in href if currentPage provided in options', () => {
-      options = { currentPage: 2 };
-      const expected = `${endpoint}?page=${options.currentPage - 1}`;
-
-      (service as any).getFindAllHref(options).subscribe((value) => {
-        expect(value).toBe(expected);
-      });
-    });
-
-    it('should include size in href if elementsPerPage provided in options', () => {
-      options = { elementsPerPage: 5 };
-      const expected = `${endpoint}?size=${options.elementsPerPage}`;
-
-      (service as any).getFindAllHref(options).subscribe((value) => {
-        expect(value).toBe(expected);
-      });
-    });
-
-    it('should include sort href if SortOptions provided in options', () => {
-      const sortOptions = new SortOptions('field1', SortDirection.ASC);
-      options = { sort: sortOptions };
-      const expected = `${endpoint}?sort=${sortOptions.field},${sortOptions.direction}`;
-
-      (service as any).getFindAllHref(options).subscribe((value) => {
-        expect(value).toBe(expected);
-      });
-    });
-
-    it('should include startsWith in href if startsWith provided in options', () => {
-      options = { startsWith: 'ab' };
-      const expected = `${endpoint}?startsWith=${options.startsWith}`;
-
-      (service as any).getFindAllHref(options).subscribe((value) => {
-        expect(value).toBe(expected);
-      });
-    });
-
-    it('should include all provided options in href', () => {
-      const sortOptions = new SortOptions('field1', SortDirection.DESC);
-      options = {
-        currentPage: 6,
-        elementsPerPage: 10,
-        sort: sortOptions,
-        startsWith: 'ab',
-
-      };
-      const expected = `${endpoint}?page=${options.currentPage - 1}&size=${options.elementsPerPage}` +
-        `&sort=${sortOptions.field},${sortOptions.direction}&startsWith=${options.startsWith}`;
-
-      (service as any).getFindAllHref(options).subscribe((value) => {
-        expect(value).toBe(expected);
-      });
-    });
-
-    it('should include all searchParams in href if any provided in options', () => {
-      options = {
-        searchParams: [
-          new RequestParam('param1', 'test'),
-          new RequestParam('param2', 'test2'),
-        ]
-      };
-      const expected = `${endpoint}?param1=test&param2=test2`;
-
-      (service as any).getFindAllHref(options).subscribe((value) => {
-        expect(value).toBe(expected);
-      });
-    });
-
-    it('should include linkPath in href if any provided', () => {
-      const expected = `${endpoint}/test/entries`;
-
-      (service as any).getFindAllHref({}, 'test/entries').subscribe((value) => {
-        expect(value).toBe(expected);
-      });
-    });
-
-    it('should include single linksToFollow as embed', () => {
-      const expected = `${endpoint}?embed=bundles`;
-
-      (service as any).getFindAllHref({}, null, followLink('bundles')).subscribe((value) => {
-        expect(value).toBe(expected);
-      });
-    });
-
-    it('should include single linksToFollow as embed and its size', () => {
-      const expected = `${endpoint}?embed.size=bundles=5&embed=bundles`;
-      const config: FindListOptions = Object.assign(new FindListOptions(), {
-        elementsPerPage: 5
-      });
-      (service as any).getFindAllHref({}, null, followLink('bundles', { findListOptions: config })).subscribe((value) => {
-        expect(value).toBe(expected);
-      });
-    });
-
-    it('should include multiple linksToFollow as embed', () => {
-      const expected = `${endpoint}?embed=bundles&embed=owningCollection&embed=templateItemOf`;
-
-      (service as any).getFindAllHref({}, null, followLink('bundles'), followLink('owningCollection'), followLink('templateItemOf')).subscribe((value) => {
-        expect(value).toBe(expected);
-      });
-    });
-
-    it('should include multiple linksToFollow as embed and its sizes if given', () => {
-      const expected = `${endpoint}?embed=bundles&embed.size=owningCollection=2&embed=owningCollection&embed=templateItemOf`;
-
-      const config: FindListOptions = Object.assign(new FindListOptions(), {
-        elementsPerPage: 2
-      });
-
-      (service as any).getFindAllHref({}, null, followLink('bundles'), followLink('owningCollection', { findListOptions: config }), followLink('templateItemOf')).subscribe((value) => {
-        expect(value).toBe(expected);
-      });
-    });
-
-    it('should not include linksToFollow with shouldEmbed = false', () => {
-      const expected = `${endpoint}?embed=templateItemOf`;
-
-      (service as any).getFindAllHref(
-        {},
-        null,
-        followLink('bundles', { shouldEmbed: false }),
-        followLink('owningCollection', { shouldEmbed: false }),
-        followLink('templateItemOf')
-      ).subscribe((value) => {
-        expect(value).toBe(expected);
-      });
-    });
-
-    it('should include nested linksToFollow 3lvl', () => {
-      const expected = `${endpoint}?embed=owningCollection/itemtemplate/relationships`;
-
-      (service as any).getFindAllHref({}, null, followLink('owningCollection', {}, followLink('itemtemplate', {}, followLink('relationships')))).subscribe((value) => {
-        expect(value).toBe(expected);
-      });
-    });
-
-    it('should include nested linksToFollow 2lvl and nested embed\'s size', () => {
-      const expected = `${endpoint}?embed.size=owningCollection/itemtemplate=4&embed=owningCollection/itemtemplate`;
-      const config: FindListOptions = Object.assign(new FindListOptions(), {
-        elementsPerPage: 4
-      });
-      (service as any).getFindAllHref({}, null, followLink('owningCollection', {}, followLink('itemtemplate', { findListOptions: config }))).subscribe((value) => {
-        expect(value).toBe(expected);
-      });
-    });
-  });
-
-  describe('getIDHref', () => {
-    const endpointMock = 'https://dspace7-internal.atmire.com/server/api/core/items';
-    const resourceIdMock = '003c99b4-d4fe-44b0-a945-e12182a7ca89';
-
-    it('should return endpoint', () => {
-      const result = (service as any).getIDHref(endpointMock, resourceIdMock);
-      expect(result).toEqual(endpointMock + '/' + resourceIdMock);
-    });
-
-    it('should include single linksToFollow as embed', () => {
-      const expected = `${endpointMock}/${resourceIdMock}?embed=bundles`;
-      const result = (service as any).getIDHref(endpointMock, resourceIdMock, followLink('bundles'));
-      expect(result).toEqual(expected);
-    });
-
-    it('should include multiple linksToFollow as embed', () => {
-      const expected = `${endpointMock}/${resourceIdMock}?embed=bundles&embed=owningCollection&embed=templateItemOf`;
-      const result = (service as any).getIDHref(endpointMock, resourceIdMock, followLink('bundles'), followLink('owningCollection'), followLink('templateItemOf'));
-      expect(result).toEqual(expected);
-    });
-
-    it('should not include linksToFollow with shouldEmbed = false', () => {
-      const expected = `${endpointMock}/${resourceIdMock}?embed=templateItemOf`;
-      const result = (service as any).getIDHref(
-        endpointMock,
-        resourceIdMock,
-        followLink('bundles', { shouldEmbed: false }),
-        followLink('owningCollection', { shouldEmbed: false }),
-        followLink('templateItemOf')
-      );
-      expect(result).toEqual(expected);
-    });
-
-    it('should include nested linksToFollow 3lvl', () => {
-      const expected = `${endpointMock}/${resourceIdMock}?embed=owningCollection/itemtemplate/relationships`;
-      const result = (service as any).getIDHref(endpointMock, resourceIdMock, followLink('owningCollection', {}, followLink('itemtemplate', {}, followLink('relationships'))));
-      expect(result).toEqual(expected);
-    });
-  });
-
-  describe('patch', () => {
-    const dso = {
-      uuid: 'dso-uuid'
-    };
-    const operations = [
-      Object.assign({
-        op: 'move',
-        from: '/1',
-        path: '/5'
-      }) as Operation
-    ];
-
-    beforeEach(() => {
-      service.patch(dso, operations);
-    });
-
-    it('should send a PatchRequest', () => {
-      expect(requestService.send).toHaveBeenCalledWith(jasmine.any(PatchRequest));
-    });
-  });
-
-  describe('update', () => {
-    let operations;
-    let dso;
-    let dso2;
-    const name1 = 'random string';
-    const name2 = 'another random string';
-    beforeEach(() => {
-      operations = [{ op: 'replace', path: '/0/value', value: name2 } as Operation];
-
-      dso = Object.assign(new DSpaceObject(), {
-        _links: { self: { href: selfLink } },
-        metadata: [{ key: 'dc.title', value: name1 }]
-      });
-
-      dso2 = Object.assign(new DSpaceObject(), {
-        _links: { self: { href: selfLink } },
-        metadata: [{ key: 'dc.title', value: name2 }]
-      });
-
-      spyOn(service, 'findByHref').and.returnValue(createSuccessfulRemoteDataObject$(dso));
-      spyOn(objectCache, 'addPatch');
-    });
-
-    it('should call addPatch on the object cache with the right parameters when there are differences', () => {
-      service.update(dso2).subscribe();
-      expect(objectCache.addPatch).toHaveBeenCalledWith(selfLink, operations);
-    });
-
-    it('should not call addPatch on the object cache with the right parameters when there are no differences', () => {
-      service.update(dso).subscribe();
-      expect(objectCache.addPatch).not.toHaveBeenCalled();
-    });
-  });
-
   describe(`reRequestStaleRemoteData`, () => {
     let callback: jasmine.Spy<jasmine.Func>;
 
@@ -661,7 +370,7 @@ describe('DataService', () => {
 
   });
 
-  describe(`findAllByHref`, () => {
+  describe(`findListByHref`, () => {
     let findListOptions;
     beforeEach(() => {
       findListOptions = { currentPage: 5 };
@@ -674,7 +383,7 @@ describe('DataService', () => {
         spyOn(rdbService, 'buildList').and.returnValue(cold('a', { a: remoteDataMocks.Success }));
         spyOn(service as any, 'reRequestStaleRemoteData').and.returnValue(() => cold('a', { a: remoteDataMocks.Success }));
 
-        service.findAllByHref(selfLink, findListOptions, true, true, ...linksToFollow);
+        service.findListByHref(selfLink, findListOptions, true, true, ...linksToFollow);
         expect(service.buildHrefFromFindOptions).toHaveBeenCalledWith(selfLink, findListOptions, [], ...linksToFollow);
       });
     });
@@ -685,11 +394,11 @@ describe('DataService', () => {
         spyOn(rdbService, 'buildList').and.returnValue(cold('a', { a: remoteDataMocks.Success }));
         spyOn(service as any, 'reRequestStaleRemoteData').and.returnValue(() => cold('a', { a: remoteDataMocks.Success }));
 
-        service.findAllByHref(selfLink, findListOptions, true, true, ...linksToFollow);
+        service.findListByHref(selfLink, findListOptions, true, true, ...linksToFollow);
         expect((service as any).createAndSendGetRequest).toHaveBeenCalledWith(jasmine.anything(), true);
         expectObservable(rdbService.buildList.calls.argsFor(0)[0]).toBe('(a|)', { a: 'bingo!' });
 
-        service.findAllByHref(selfLink, findListOptions, false, true, ...linksToFollow);
+        service.findListByHref(selfLink, findListOptions, false, true, ...linksToFollow);
         expect((service as any).createAndSendGetRequest).toHaveBeenCalledWith(jasmine.anything(), false);
         expectObservable(rdbService.buildList.calls.argsFor(1)[0]).toBe('(a|)', { a: 'bingo!' });
       });
@@ -701,29 +410,29 @@ describe('DataService', () => {
         spyOn(rdbService, 'buildList').and.returnValue(cold('a', { a: remoteDataMocks.Success }));
         spyOn(service as any, 'reRequestStaleRemoteData').and.returnValue(() => cold('a', { a: remoteDataMocks.Success }));
 
-        service.findAllByHref(selfLink, findListOptions, true, true, ...linksToFollow);
+        service.findListByHref(selfLink, findListOptions, true, true, ...linksToFollow);
         expect(rdbService.buildList).toHaveBeenCalledWith(jasmine.anything() as any, ...linksToFollow);
         expectObservable(rdbService.buildList.calls.argsFor(0)[0]).toBe('(a|)', { a: 'bingo!' });
       });
     });
 
-    it(`should call reRequestStaleRemoteData with reRequestOnStale and the exact same findAllByHref call as a callback`, () => {
+    it(`should call reRequestStaleRemoteData with reRequestOnStale and the exact same findListByHref call as a callback`, () => {
       testScheduler.run(({ cold, expectObservable }) => {
         spyOn(service, 'buildHrefFromFindOptions').and.returnValue('bingo!');
         spyOn(rdbService, 'buildList').and.returnValue(cold('a', { a: remoteDataMocks.SuccessStale }));
         spyOn(service as any, 'reRequestStaleRemoteData').and.returnValue(() => cold('a', { a: remoteDataMocks.SuccessStale }));
 
-        service.findAllByHref(selfLink, findListOptions, true, true, ...linksToFollow);
+        service.findListByHref(selfLink, findListOptions, true, true, ...linksToFollow);
         expect((service as any).reRequestStaleRemoteData.calls.argsFor(0)[0]).toBeTrue();
-        spyOn(service, 'findAllByHref').and.returnValue(cold('a', { a: remoteDataMocks.SuccessStale }));
+        spyOn(service, 'findListByHref').and.returnValue(cold('a', { a: remoteDataMocks.SuccessStale }));
         // prove that the spy we just added hasn't been called yet
-        expect(service.findAllByHref).not.toHaveBeenCalled();
+        expect(service.findListByHref).not.toHaveBeenCalled();
         // call the callback passed to reRequestStaleRemoteData
         (service as any).reRequestStaleRemoteData.calls.argsFor(0)[1]();
-        // verify that findAllByHref _has_ been called now, with the same params as the original call
+        // verify that findListByHref _has_ been called now, with the same params as the original call
-        expect(service.findAllByHref).toHaveBeenCalledWith(jasmine.anything(), findListOptions, true, true, ...linksToFollow);
+        expect(service.findListByHref).toHaveBeenCalledWith(jasmine.anything(), findListOptions, true, true, ...linksToFollow);
         // ... except for selflink, which will have been turned in to an observable.
-        expectObservable((service.findAllByHref as jasmine.Spy).calls.argsFor(0)[0]).toBe('(a|)', { a: selfLink });
+        expectObservable((service.findListByHref as jasmine.Spy).calls.argsFor(0)[0]).toBe('(a|)', { a: selfLink });
       });
     });
 
@@ -737,7 +446,7 @@ describe('DataService', () => {
           a: 'bingo!',
         };
 
-        expectObservable(service.findAllByHref(selfLink, findListOptions, true, true, ...linksToFollow)).toBe(expected, values);
+        expectObservable(service.findListByHref(selfLink, findListOptions, true, true, ...linksToFollow)).toBe(expected, values);
       });
     });
 
@@ -765,7 +474,7 @@ describe('DataService', () => {
             e: remoteDataMocks.SuccessStale,
           };
 
-          expectObservable(service.findAllByHref(selfLink, findListOptions, true, true, ...linksToFollow)).toBe(expected, values);
+          expectObservable(service.findListByHref(selfLink, findListOptions, true, true, ...linksToFollow)).toBe(expected, values);
         });
       });
 
@@ -786,7 +495,7 @@ describe('DataService', () => {
             e: remoteDataMocks.SuccessStale,
           };
 
-          expectObservable(service.findAllByHref(selfLink, findListOptions, true, true, ...linksToFollow)).toBe(expected, values);
+          expectObservable(service.findListByHref(selfLink, findListOptions, true, true, ...linksToFollow)).toBe(expected, values);
         });
       });
 
@@ -816,7 +525,7 @@ describe('DataService', () => {
             e: remoteDataMocks.SuccessStale,
           };
 
-          expectObservable(service.findAllByHref(selfLink, findListOptions, false, true, ...linksToFollow)).toBe(expected, values);
+          expectObservable(service.findListByHref(selfLink, findListOptions, false, true, ...linksToFollow)).toBe(expected, values);
         });
       });
 
@@ -837,7 +546,7 @@ describe('DataService', () => {
             e: remoteDataMocks.SuccessStale,
           };
 
-          expectObservable(service.findAllByHref(selfLink, findListOptions, false, true, ...linksToFollow)).toBe(expected, values);
+          expectObservable(service.findListByHref(selfLink, findListOptions, false, true, ...linksToFollow)).toBe(expected, values);
         });
       });
 
@@ -915,97 +624,4 @@ describe('DataService', () => {
       });
     });
   });
-
-  describe('delete', () => {
-    let MOCK_SUCCEEDED_RD;
-    let MOCK_FAILED_RD;
-
-    let invalidateByHrefSpy: jasmine.Spy;
-    let buildFromRequestUUIDSpy: jasmine.Spy;
-    let getIDHrefObsSpy: jasmine.Spy;
-    let deleteByHrefSpy: jasmine.Spy;
-
-    beforeEach(() => {
-      invalidateByHrefSpy = spyOn(service, 'invalidateByHref').and.returnValue(observableOf(true));
-      buildFromRequestUUIDSpy = spyOn(rdbService, 'buildFromRequestUUID').and.callThrough();
-      getIDHrefObsSpy = spyOn(service, 'getIDHrefObs').and.callThrough();
-      deleteByHrefSpy = spyOn(service, 'deleteByHref').and.callThrough();
-
-      MOCK_SUCCEEDED_RD = createSuccessfulRemoteDataObject({});
-      MOCK_FAILED_RD = createFailedRemoteDataObject('something went wrong');
-    });
-
-    it('should retrieve href by ID and call deleteByHref', () => {
-      getIDHrefObsSpy.and.returnValue(observableOf('some-href'));
-      buildFromRequestUUIDSpy.and.returnValue(createSuccessfulRemoteDataObject$({}));
-
-      service.delete('some-id', ['a', 'b', 'c']).subscribe(rd => {
-        expect(getIDHrefObsSpy).toHaveBeenCalledWith('some-id');
-        expect(deleteByHrefSpy).toHaveBeenCalledWith('some-href', ['a', 'b', 'c']);
-      });
-    });
-
-    describe('deleteByHref', () => {
-      it('should call invalidateByHref if the DELETE request succeeds', (done) => {
-        buildFromRequestUUIDSpy.and.returnValue(observableOf(MOCK_SUCCEEDED_RD));
-
-        service.deleteByHref('some-href').subscribe(rd => {
-          expect(rd).toBe(MOCK_SUCCEEDED_RD);
-          expect(invalidateByHrefSpy).toHaveBeenCalled();
-          done();
-        });
-      });
-
-      it('should call invalidateByHref even if not subscribing to returned Observable', fakeAsync(() => {
-        buildFromRequestUUIDSpy.and.returnValue(observableOf(MOCK_SUCCEEDED_RD));
-
-        service.deleteByHref('some-href');
-        tick();
-
-        expect(invalidateByHrefSpy).toHaveBeenCalled();
-      }));
-
-      it('should not call invalidateByHref if the DELETE request fails', (done) => {
-        buildFromRequestUUIDSpy.and.returnValue(observableOf(MOCK_FAILED_RD));
-
-        service.deleteByHref('some-href').subscribe(rd => {
-          expect(rd).toBe(MOCK_FAILED_RD);
-          expect(invalidateByHrefSpy).not.toHaveBeenCalled();
-          done();
-        });
-      });
-
-      it('should wait for invalidateByHref before emitting', () => {
-        testScheduler.run(({ cold, expectObservable }) => {
-          buildFromRequestUUIDSpy.and.returnValue(
-            cold('(r|)', { r: MOCK_SUCCEEDED_RD})      // RD emits right away
-          );
-          invalidateByHrefSpy.and.returnValue(
-            cold('----(t|)', BOOLEAN)                  // but we pretend that setting requests to stale takes longer
-          );
-
-          const done$ = service.deleteByHref('some-href');
-          expectObservable(done$).toBe(
-            '----(r|)', { r: MOCK_SUCCEEDED_RD}        // ...and expect the returned Observable to wait until that's done
-          );
-        });
-      });
-
-      it('should wait for the DELETE request to resolve before emitting', () => {
-        testScheduler.run(({ cold, expectObservable }) => {
-          buildFromRequestUUIDSpy.and.returnValue(
-            cold('----(r|)', { r: MOCK_SUCCEEDED_RD})   // the request takes a while
-          );
-          invalidateByHrefSpy.and.returnValue(
-            cold('(t|)', BOOLEAN)                       // but we pretend that setting to stale happens sooner
-          );                                            // e.g.: maybe already stale before this call?
-
-          const done$ = service.deleteByHref('some-href');
-          expectObservable(done$).toBe(
-            '----(r|)', { r: MOCK_SUCCEEDED_RD}         // ...and expect the returned Observable to wait for the request
-          );
-        });
-      });
-    });
-  });
 });

src/app/core/data/base/base-data.service.ts

@@ -0,0 +1,374 @@
+/**
+ * The contents of this file are subject to the license and copyright
+ * detailed in the LICENSE and NOTICE files at the root of the source
+ * tree and available online at
+ *
+ * http://www.dspace.org/license/
+ */
+
+import { AsyncSubject, from as observableFrom, Observable, of as observableOf } from 'rxjs';
+import { map, mergeMap, skipWhile, switchMap, take, tap, toArray } from 'rxjs/operators';
+import { hasValue, isNotEmpty, isNotEmptyOperator } from '../../../shared/empty.util';
+import { FollowLinkConfig } from '../../../shared/utils/follow-link-config.model';
+import { RemoteDataBuildService } from '../../cache/builders/remote-data-build.service';
+import { RequestParam } from '../../cache/models/request-param.model';
+import { HALEndpointService } from '../../shared/hal-endpoint.service';
+import { URLCombiner } from '../../url-combiner/url-combiner';
+import { RemoteData } from '../remote-data';
+import { GetRequest } from '../request.models';
+import { RequestService } from '../request.service';
+import { CacheableObject } from '../../cache/cacheable-object.model';
+import { FindListOptions } from '../find-list-options.model';
+import { PaginatedList } from '../paginated-list.model';
+import { ObjectCacheEntry } from '../../cache/object-cache.reducer';
+import { ObjectCacheService } from '../../cache/object-cache.service';
+import { HALDataService } from './hal-data-service.interface';
+
+/**
+ * Common functionality for data services.
+ * Specific functionality that not all services would need
+ * is implemented in "DataService feature" classes (e.g. {@link CreateData}
+ *
+ * All DataService (or DataService feature) classes must
+ *   - extend this class (or {@link IdentifiableDataService})
+ *   - implement any DataService features it requires in order to forward calls to it
+ *
+ * ```
+ * export class SomeDataService extends BaseDataService<Something> implements CreateData<Something>, SearchData<Something> {
+ *   private createData: CreateData<Something>;
+ *   private searchData: SearchDataData<Something>;
+ *
+ *   create(...) {
+ *     return this.createData.create(...);
+ *   }
+ *
+ *   searchBy(...) {
+ *     return this.searchData.searchBy(...);
+ *   }
+ * }
+ * ```
+ */
+export class BaseDataService<T extends CacheableObject> implements HALDataService<T> {
+  constructor(
+    protected linkPath: string,
+    protected requestService: RequestService,
+    protected rdbService: RemoteDataBuildService,
+    protected objectCache: ObjectCacheService,
+    protected halService: HALEndpointService,
+    protected responseMsToLive?: number,
+  ) {
+  }
+
+  /**
+   * Allows subclasses to reset the response cache time.
+   */
+
+  /**
+   * Get the endpoint for browsing
+   * @param options The [[FindListOptions]] object
+   * @param linkPath The link path for the object
+   * @returns {Observable<string>}
+   */
+  getBrowseEndpoint(options: FindListOptions = {}, linkPath?: string): Observable<string> {
+    return this.getEndpoint();
+  }
+
+  /**
+   * Get the base endpoint for all requests
+   */
+  protected getEndpoint(): Observable<string> {
+    return this.halService.getEndpoint(this.linkPath);
+  }
+
+  /**
+   * Turn an options object into a query string and combine it with the given HREF
+   *
+   * @param href The HREF to which the query string should be appended
+   * @param options The [[FindListOptions]] object
+   * @param extraArgs Array with additional params to combine with query string
+   * @return {Observable<string>}
+   *    Return an observable that emits created HREF
+   * @param linksToFollow   List of {@link FollowLinkConfig} that indicate which {@link HALLink}s should be automatically resolved
+   */
+  public buildHrefFromFindOptions(href: string, options: FindListOptions, extraArgs: string[] = [], ...linksToFollow: FollowLinkConfig<T>[]): string {
+    let args = [...extraArgs];
+
+    if (hasValue(options.currentPage) && typeof options.currentPage === 'number') {
+      /* TODO: this is a temporary fix for the pagination start index (0 or 1) discrepancy between the rest and the frontend respectively */
+      args = this.addHrefArg(href, args, `page=${options.currentPage - 1}`);
+    }
+    if (hasValue(options.elementsPerPage)) {
+      args = this.addHrefArg(href, args, `size=${options.elementsPerPage}`);
+    }
+    if (hasValue(options.sort)) {
+      args = this.addHrefArg(href, args, `sort=${options.sort.field},${options.sort.direction}`);
+    }
+    if (hasValue(options.startsWith)) {
+      args = this.addHrefArg(href, args, `startsWith=${options.startsWith}`);
+    }
+    if (hasValue(options.searchParams)) {
+      options.searchParams.forEach((param: RequestParam) => {
+        args = this.addHrefArg(href, args, `${param.fieldName}=${param.fieldValue}`);
+      });
+    }
+    args = this.addEmbedParams(href, args, ...linksToFollow);
+    if (isNotEmpty(args)) {
+      return new URLCombiner(href, `?${args.join('&')}`).toString();
+    } else {
+      return href;
+    }
+  }
+
+  /**
+   * Turn an array of RequestParam into a query string and combine it with the given HREF
+   *
+   * @param href The HREF to which the query string should be appended
+   * @param params Array with additional params to combine with query string
+   * @param linksToFollow   List of {@link FollowLinkConfig} that indicate which {@link HALLink}s should be automatically resolved
+   *
+   * @return {Observable<string>}
+   * Return an observable that emits created HREF
+   */
+  buildHrefWithParams(href: string, params: RequestParam[], ...linksToFollow: FollowLinkConfig<T>[]): string {
+
+    let  args = [];
+    if (hasValue(params)) {
+      params.forEach((param: RequestParam) => {
+        args = this.addHrefArg(href, args, `${param.fieldName}=${param.fieldValue}`);
+      });
+    }
+
+    args = this.addEmbedParams(href, args, ...linksToFollow);
+
+    if (isNotEmpty(args)) {
+      return new URLCombiner(href, `?${args.join('&')}`).toString();
+    } else {
+      return href;
+    }
+  }
+  /**
+   * Adds the embed options to the link for the request
+   * @param href            The href the params are to be added to
+   * @param args            params for the query string
+   * @param linksToFollow   links we want to embed in query string if shouldEmbed is true
+   */
+  protected addEmbedParams(href: string, args: string[], ...linksToFollow: FollowLinkConfig<T>[]) {
+    linksToFollow.forEach((linkToFollow: FollowLinkConfig<T>) => {
+      if (hasValue(linkToFollow) && linkToFollow.shouldEmbed) {
+        const embedString = 'embed=' + String(linkToFollow.name);
+        // Add the embeds size if given in the FollowLinkConfig.FindListOptions
+        if (hasValue(linkToFollow.findListOptions) && hasValue(linkToFollow.findListOptions.elementsPerPage)) {
+          args = this.addHrefArg(href, args,
+            'embed.size=' + String(linkToFollow.name) + '=' + linkToFollow.findListOptions.elementsPerPage);
+        }
+        // Adds the nested embeds and their size if given
+        if (isNotEmpty(linkToFollow.linksToFollow)) {
+          args = this.addNestedEmbeds(embedString, href, args, ...linkToFollow.linksToFollow);
+        } else {
+          args = this.addHrefArg(href, args, embedString);
+        }
+      }
+    });
+    return args;
+  }
+
+  /**
+   * Add a new argument to the list of arguments, only if it doesn't already exist in the given href,
+   * or the current list of arguments
+   *
+   * @param href        The href the arguments are to be added to
+   * @param currentArgs The current list of arguments
+   * @param newArg      The new argument to add
+   * @return            The next list of arguments, with newArg included if it wasn't already.
+   *                    Note this function will not modify any of the input params.
+   */
+  protected addHrefArg(href: string, currentArgs: string[], newArg: string): string[] {
+    if (href.includes(newArg) || currentArgs.includes(newArg)) {
+      return [...currentArgs];
+    } else {
+      return [...currentArgs, newArg];
+    }
+  }
+
+  /**
+   * Add the nested followLinks to the embed param, separated by a /, and their sizes, recursively
+   * @param embedString     embedString so far (recursive)
+   * @param href            The href the params are to be added to
+   * @param args            params for the query string
+   * @param linksToFollow   links we want to embed in query string if shouldEmbed is true
+   */
+  protected addNestedEmbeds(embedString: string, href: string, args: string[], ...linksToFollow: FollowLinkConfig<T>[]): string[] {
+    let nestEmbed = embedString;
+    linksToFollow.forEach((linkToFollow: FollowLinkConfig<T>) => {
+      if (hasValue(linkToFollow) && linkToFollow.shouldEmbed) {
+        nestEmbed = nestEmbed + '/' + String(linkToFollow.name);
+        // Add the nested embeds size if given in the FollowLinkConfig.FindListOptions
+        if (hasValue(linkToFollow.findListOptions) && hasValue(linkToFollow.findListOptions.elementsPerPage)) {
+          const nestedEmbedSize = 'embed.size=' + nestEmbed.split('=')[1] + '=' + linkToFollow.findListOptions.elementsPerPage;
+          args = this.addHrefArg(href, args, nestedEmbedSize);
+        }
+        if (hasValue(linkToFollow.linksToFollow) && isNotEmpty(linkToFollow.linksToFollow)) {
+          args = this.addNestedEmbeds(nestEmbed, href, args, ...linkToFollow.linksToFollow);
+        } else {
+          args = this.addHrefArg(href, args, nestEmbed);
+        }
+      }
+    });
+    return args;
+  }
+
+  /**
+   * An operator that will call the given function if the incoming RemoteData is stale and
+   * shouldReRequest is true
+   *
+   * @param shouldReRequest  Whether or not to call the re-request function if the RemoteData is stale
+   * @param requestFn        The function to call if the RemoteData is stale and shouldReRequest is
+   *                         true
+   */
+  protected reRequestStaleRemoteData<O>(shouldReRequest: boolean, requestFn: () => Observable<RemoteData<O>>) {
+    return (source: Observable<RemoteData<O>>): Observable<RemoteData<O>> => {
+      if (shouldReRequest === true) {
+        return source.pipe(
+          tap((remoteData: RemoteData<O>) => {
+            if (hasValue(remoteData) && remoteData.isStale) {
+              requestFn();
+            }
+          })
+        );
+      } else {
+        return source;
+      }
+    };
+  }
+
+  /**
+   * Returns an observable of {@link RemoteData} of an object, based on an href, with a list of
+   * {@link FollowLinkConfig}, to automatically resolve {@link HALLink}s of the object
+   * @param href$                       The url of object we want to retrieve. Can be a string or
+   *                                    an Observable<string>
+   * @param useCachedVersionIfAvailable If this is true, the request will only be sent if there's
+   *                                    no valid cached version. Defaults to true
+   * @param reRequestOnStale            Whether or not the request should automatically be re-
+   *                                    requested after the response becomes stale
+   * @param linksToFollow               List of {@link FollowLinkConfig} that indicate which
+   *                                    {@link HALLink}s should be automatically resolved
+   */
+  findByHref(href$: string | Observable<string>, useCachedVersionIfAvailable = true, reRequestOnStale = true, ...linksToFollow: FollowLinkConfig<T>[]): Observable<RemoteData<T>> {
+    if (typeof href$ === 'string') {
+      href$ = observableOf(href$);
+    }
+
+    const requestHref$ = href$.pipe(
+      isNotEmptyOperator(),
+      take(1),
+      map((href: string) => this.buildHrefFromFindOptions(href, {}, [], ...linksToFollow)),
+    );
+
+    this.createAndSendGetRequest(requestHref$, useCachedVersionIfAvailable);
+
+    return this.rdbService.buildSingle<T>(requestHref$, ...linksToFollow).pipe(
+      // This skip ensures that if a stale object is present in the cache when you do a
+      // call it isn't immediately returned, but we wait until the remote data for the new request
+      // is created. If useCachedVersionIfAvailable is false it also ensures you don't get a
+      // cached completed object
+      skipWhile((rd: RemoteData<T>) => useCachedVersionIfAvailable ? rd.isStale : rd.hasCompleted),
+      this.reRequestStaleRemoteData(reRequestOnStale, () =>
+        this.findByHref(href$, useCachedVersionIfAvailable, reRequestOnStale, ...linksToFollow)),
+    );
+  }
+
+  /**
+   * Returns an Observable of a {@link RemoteData} of a {@link PaginatedList} of objects, based on an href,
+   * with a list of {@link FollowLinkConfig}, to automatically resolve {@link HALLink}s of the object
+   *
+   * @param href$                       The url of list we want to retrieve. Can be a string or an Observable<string>
+   * @param options
+   * @param useCachedVersionIfAvailable If this is true, the request will only be sent if there's no valid cached version.
+   * @param reRequestOnStale            Whether or not the request should automatically be re-requested after the response becomes stale
+   * @param linksToFollow               List of {@link FollowLinkConfig} that indicate which {@link HALLink}s should be automatically resolved
+   */
+  findListByHref(href$: string | Observable<string>, options: FindListOptions = {}, useCachedVersionIfAvailable = true, reRequestOnStale = true, ...linksToFollow: FollowLinkConfig<T>[]): Observable<RemoteData<PaginatedList<T>>> {
+    if (typeof href$ === 'string') {
+      href$ = observableOf(href$);
+    }
+
+    const requestHref$ = href$.pipe(
+      isNotEmptyOperator(),
+      take(1),
+      map((href: string) => this.buildHrefFromFindOptions(href, options, [], ...linksToFollow)),
+    );
+
+    this.createAndSendGetRequest(requestHref$, useCachedVersionIfAvailable);
+
+    return this.rdbService.buildList<T>(requestHref$, ...linksToFollow).pipe(
+      // This skip ensures that if a stale object is present in the cache when you do a
+      // call it isn't immediately returned, but we wait until the remote data for the new request
+      // is created. If useCachedVersionIfAvailable is false it also ensures you don't get a
+      // cached completed object
+      skipWhile((rd: RemoteData<PaginatedList<T>>) => useCachedVersionIfAvailable ? rd.isStale : rd.hasCompleted),
+      this.reRequestStaleRemoteData(reRequestOnStale, () =>
+        this.findListByHref(href$, options, useCachedVersionIfAvailable, reRequestOnStale, ...linksToFollow)),
+    );
+  }
+
+  /**
+   * Create a GET request for the given href, and send it.
+   *
+   * @param href$                       The url of object we want to retrieve. Can be a string or
+   *                                    an Observable<string>
+   * @param useCachedVersionIfAvailable If this is true, the request will only be sent if there's
+   *                                    no valid cached version. Defaults to true
+   */
+  protected createAndSendGetRequest(href$: string | Observable<string>, useCachedVersionIfAvailable = true): void {
+    if (isNotEmpty(href$)) {
+      if (typeof href$ === 'string') {
+        href$ = observableOf(href$);
+      }
+
+      href$.pipe(
+        isNotEmptyOperator(),
+        take(1)
+      ).subscribe((href: string) => {
+        const requestId = this.requestService.generateRequestId();
+        const request = new GetRequest(requestId, href);
+        if (hasValue(this.responseMsToLive)) {
+          request.responseMsToLive = this.responseMsToLive;
+        }
+        this.requestService.send(request, useCachedVersionIfAvailable);
+      });
+    }
+  }
+
+  /**
+   * Return the links to traverse from the root of the api to the
+   * endpoint this DataService represents
+   *
+   * e.g. if the api root links to 'foo', and the endpoint at 'foo'
+   * links to 'bar' the linkPath for the BarDataService would be
+   * 'foo/bar'
+   */
+  getLinkPath(): string {
+    return this.linkPath;
+  }
+
+  /**
+   * Invalidate a cached object by its href
+   * @param href  the href to invalidate
+   */
+  public invalidateByHref(href: string): Observable<boolean> {
+    const done$ = new AsyncSubject<boolean>();
+
+    this.objectCache.getByHref(href).pipe(
+      take(1),
+      switchMap((oce: ObjectCacheEntry) => observableFrom(oce.requestUUIDs).pipe(
+        mergeMap((requestUUID: string) => this.requestService.setStaleByUUID(requestUUID)),
+        toArray(),
+      )),
+    ).subscribe(() => {
+      done$.next(true);
+      done$.complete();
+    });
+
+    return done$;
+  }
+}

src/app/core/data/base/create-data.spec.ts

@@ -0,0 +1,225 @@
+/**
+ * The contents of this file are subject to the license and copyright
+ * detailed in the LICENSE and NOTICE files at the root of the source
+ * tree and available online at
+ *
+ * http://www.dspace.org/license/
+ */
+import { RequestService } from '../request.service';
+import { RemoteDataBuildService } from '../../cache/builders/remote-data-build.service';
+import { ObjectCacheService } from '../../cache/object-cache.service';
+import { HALEndpointService } from '../../shared/hal-endpoint.service';
+import { FindListOptions } from '../find-list-options.model';
+import { Observable, of as observableOf } from 'rxjs';
+import { CreateData, CreateDataImpl } from './create-data';
+import { NotificationsService } from '../../../shared/notifications/notifications.service';
+import { getMockRequestService } from '../../../shared/mocks/request.service.mock';
+import { HALEndpointServiceStub } from '../../../shared/testing/hal-endpoint-service.stub';
+import { getMockRemoteDataBuildService } from '../../../shared/mocks/remote-data-build.service.mock';
+import { RemoteData } from '../remote-data';
+import { RequestEntryState } from '../request-entry-state.model';
+import { createFailedRemoteDataObject, createSuccessfulRemoteDataObject } from '../../../shared/remote-data.utils';
+import { RequestParam } from '../../cache/models/request-param.model';
+import { RestRequestMethod } from '../rest-request-method';
+import { DSpaceObject } from '../../shared/dspace-object.model';
+
+/**
+ * Tests whether calls to `CreateData` methods are correctly patched through in a concrete data service that implements it
+ */
+export function testCreateDataImplementation(serviceFactory: () => CreateData<any>) {
+  let service;
+
+  describe('CreateData implementation', () => {
+    const OBJ = Object.assign(new DSpaceObject(), {
+      uuid: '08eec68f-45e4-47a3-80c5-f0beb5627079',
+    });
+    const PARAMS = [
+      new RequestParam('abc', 123), new RequestParam('def', 456),
+    ];
+
+    beforeAll(() => {
+      service = serviceFactory();
+
+      (service as any).createData = jasmine.createSpyObj('createData', {
+        create: 'TEST create',
+      });
+    });
+
+    it('should handle calls to create', () => {
+      const out: any = service.create(OBJ, ...PARAMS);
+
+      expect((service as any).createData.create).toHaveBeenCalledWith(OBJ, ...PARAMS);
+      expect(out).toBe('TEST create');
+    });
+  });
+}
+
+const endpoint = 'https://rest.api/core';
+
+class TestService extends CreateDataImpl<any> {
+  constructor(
+    protected requestService: RequestService,
+    protected rdbService: RemoteDataBuildService,
+    protected objectCache: ObjectCacheService,
+    protected halService: HALEndpointService,
+    protected notificationsService: NotificationsService,
+  ) {
+    super('test', requestService, rdbService, objectCache, halService, notificationsService, undefined);
+  }
+
+  public getEndpoint(options: FindListOptions = {}, linkPath: string = this.linkPath): Observable<string> {
+    return observableOf(endpoint);
+  }
+}
+
+describe('CreateDataImpl', () => {
+  let service: TestService;
+  let requestService;
+  let halService;
+  let rdbService;
+  let objectCache;
+  let notificationsService;
+  let remoteDataMocks;
+  let obj;
+
+  let MOCK_SUCCEEDED_RD;
+  let MOCK_FAILED_RD;
+
+  let buildFromRequestUUIDSpy: jasmine.Spy;
+  let createOnEndpointSpy: jasmine.Spy;
+
+  function initTestService(): TestService {
+    requestService = getMockRequestService();
+    halService = new HALEndpointServiceStub('url') as any;
+    rdbService = getMockRemoteDataBuildService();
+    objectCache = {
+
+      addPatch: () => {
+        /* empty */
+      },
+      getObjectBySelfLink: () => {
+        /* empty */
+      },
+      getByHref: () => {
+        /* empty */
+      },
+    } as any;
+    notificationsService = jasmine.createSpyObj('notificationsService', {
+      error: undefined,
+    });
+
+    obj = {
+      uuid: '1698f1d3-be98-4c51-9fd8-6bfedcbd59b7',
+    };
+
+    const timeStamp = new Date().getTime();
+    const msToLive = 15 * 60 * 1000;
+    const payload = { foo: 'bar' };
+    const statusCodeSuccess = 200;
+    const statusCodeError = 404;
+    const errorMessage = 'not found';
+    remoteDataMocks = {
+      RequestPending: new RemoteData(undefined, msToLive, timeStamp, RequestEntryState.RequestPending, undefined, undefined, undefined),
+      ResponsePending: new RemoteData(undefined, msToLive, timeStamp, RequestEntryState.ResponsePending, undefined, undefined, undefined),
+      Success: new RemoteData(timeStamp, msToLive, timeStamp, RequestEntryState.Success, undefined, payload, statusCodeSuccess),
+      SuccessStale: new RemoteData(timeStamp, msToLive, timeStamp, RequestEntryState.SuccessStale, undefined, payload, statusCodeSuccess),
+      Error: new RemoteData(timeStamp, msToLive, timeStamp, RequestEntryState.Error, errorMessage, undefined, statusCodeError),
+      ErrorStale: new RemoteData(timeStamp, msToLive, timeStamp, RequestEntryState.ErrorStale, errorMessage, undefined, statusCodeError),
+    };
+
+    return new TestService(
+      requestService,
+      rdbService,
+      objectCache,
+      halService,
+      notificationsService,
+    );
+  }
+
+  beforeEach(() => {
+    service = initTestService();
+
+    buildFromRequestUUIDSpy = spyOn(rdbService, 'buildFromRequestUUID').and.callThrough();
+    createOnEndpointSpy = spyOn(service, 'createOnEndpoint').and.callThrough();
+
+    MOCK_SUCCEEDED_RD = createSuccessfulRemoteDataObject({});
+    MOCK_FAILED_RD = createFailedRemoteDataObject('something went wrong');
+  });
+
+  describe('create', () => {
+    it('should POST the object to the root endpoint with the given parameters and return the remote data', (done) => {
+      const params = [
+        new RequestParam('abc', 123), new RequestParam('def', 456)
+      ];
+      buildFromRequestUUIDSpy.and.returnValue(observableOf(remoteDataMocks.Success));
+
+      service.create(obj, ...params).subscribe(out => {
+        expect(createOnEndpointSpy).toHaveBeenCalledWith(obj, jasmine.anything());
+        expect(requestService.send).toHaveBeenCalledWith(jasmine.objectContaining({
+          method: RestRequestMethod.POST,
+          uuid: requestService.generateRequestId(),
+          href: 'https://rest.api/core?abc=123&def=456',
+          body: JSON.stringify(obj),
+        }));
+        expect(buildFromRequestUUIDSpy).toHaveBeenCalledWith(requestService.generateRequestId());
+        expect(out).toEqual(remoteDataMocks.Success);
+        done();
+      });
+    });
+  });
+
+  describe('createOnEndpoint', () => {
+    beforeEach(() => {
+      buildFromRequestUUIDSpy.and.returnValue(observableOf(remoteDataMocks.Success));
+    });
+
+    it('should send a POST request with the object as JSON', (done) => {
+      service.createOnEndpoint(obj, observableOf('https://rest.api/core/custom?search')).subscribe(out => {
+        expect(requestService.send).toHaveBeenCalledWith(jasmine.objectContaining({
+          method: RestRequestMethod.POST,
+          body: JSON.stringify(obj),
+        }));
+        done();
+      });
+    });
+
+    it('should send the POST request to the given endpoint', (done) => {
+
+      service.createOnEndpoint(obj, observableOf('https://rest.api/core/custom?search')).subscribe(out => {
+        expect(requestService.send).toHaveBeenCalledWith(jasmine.objectContaining({
+          method: RestRequestMethod.POST,
+          href: 'https://rest.api/core/custom?search',
+        }));
+        done();
+      });
+    });
+
+    it('should return the remote data for the sent request', (done) => {
+      service.createOnEndpoint(obj, observableOf('https://rest.api/core/custom?search')).subscribe(out => {
+        expect(requestService.send).toHaveBeenCalledWith(jasmine.objectContaining({
+          method: RestRequestMethod.POST,
+          uuid: requestService.generateRequestId(),
+        }));
+        expect(buildFromRequestUUIDSpy).toHaveBeenCalledWith(requestService.generateRequestId());
+        expect(notificationsService.error).not.toHaveBeenCalled();
+        expect(out).toEqual(remoteDataMocks.Success);
+        done();
+      });
+    });
+
+    it('should show an error notification if the request fails', (done) => {
+      buildFromRequestUUIDSpy.and.returnValue(observableOf(remoteDataMocks.Error));
+
+      service.createOnEndpoint(obj, observableOf('https://rest.api/core/custom?search')).subscribe(out => {
+        expect(requestService.send).toHaveBeenCalledWith(jasmine.objectContaining({
+          method: RestRequestMethod.POST,
+          uuid: requestService.generateRequestId(),
+        }));
+        expect(buildFromRequestUUIDSpy).toHaveBeenCalledWith(requestService.generateRequestId());
+        expect(notificationsService.error).toHaveBeenCalled();
+        expect(out).toEqual(remoteDataMocks.Error);
+        done();
+      });
+    });
+  });
+});

src/app/core/data/base/create-data.ts

@@ -0,0 +1,107 @@
+/**
+ * The contents of this file are subject to the license and copyright
+ * detailed in the LICENSE and NOTICE files at the root of the source
+ * tree and available online at
+ *
+ * http://www.dspace.org/license/
+ */
+import { CacheableObject } from '../../cache/cacheable-object.model';
+import { BaseDataService } from './base-data.service';
+import { RequestParam } from '../../cache/models/request-param.model';
+import { Observable } from 'rxjs';
+import { RemoteData } from '../remote-data';
+import { hasValue, isNotEmptyOperator } from '../../../shared/empty.util';
+import { distinctUntilChanged, map, take, takeWhile } from 'rxjs/operators';
+import { DSpaceSerializer } from '../../dspace-rest/dspace.serializer';
+import { getClassForType } from '../../cache/builders/build-decorators';
+import { CreateRequest } from '../request.models';
+import { NotificationOptions } from '../../../shared/notifications/models/notification-options.model';
+import { RequestService } from '../request.service';
+import { RemoteDataBuildService } from '../../cache/builders/remote-data-build.service';
+import { HALEndpointService } from '../../shared/hal-endpoint.service';
+import { NotificationsService } from '../../../shared/notifications/notifications.service';
+import { ObjectCacheService } from '../../cache/object-cache.service';
+
+/**
+ * Interface for a data service that can create objects.
+ */
+export interface CreateData<T extends CacheableObject> {
+  /**
+   * Create a new DSpaceObject on the server, and store the response
+   * in the object cache
+   *
+   * @param object  The object to create
+   * @param params  Array with additional params to combine with query string
+   */
+  create(object: T, ...params: RequestParam[]): Observable<RemoteData<T>>;
+}
+
+/**
+ * A DataService feature to create objects.
+ *
+ * Concrete data services can use this feature by implementing {@link CreateData}
+ * and delegating its method to an inner instance of this class.
+ */
+export class CreateDataImpl<T extends CacheableObject> extends BaseDataService<T> implements CreateData<T> {
+  constructor(
+    protected linkPath: string,
+    protected requestService: RequestService,
+    protected rdbService: RemoteDataBuildService,
+    protected objectCache: ObjectCacheService,
+    protected halService: HALEndpointService,
+    protected notificationsService: NotificationsService,
+    protected responseMsToLive: number,
+  ) {
+    super(linkPath, requestService, rdbService, objectCache, halService, responseMsToLive);
+  }
+
+  /**
+   * Create a new object on the server, and store the response in the object cache
+   *
+   * @param object    The object to create
+   * @param params    Array with additional params to combine with query string
+   */
+  create(object: T, ...params: RequestParam[]): Observable<RemoteData<T>> {
+    const endpoint$ = this.getEndpoint().pipe(
+      isNotEmptyOperator(),
+      distinctUntilChanged(),
+      map((endpoint: string) => this.buildHrefWithParams(endpoint, params)),
+    );
+    return this.createOnEndpoint(object, endpoint$);
+  }
+
+  /**
+   * Send a POST request to create a new resource to a specific endpoint.
+   * Use this method if the endpoint needs to be adjusted. In most cases {@link create} should be sufficient.
+   * @param object     the object to create
+   * @param endpoint$  the endpoint to send the POST request to
+   */
+  createOnEndpoint(object: T, endpoint$: Observable<string>): Observable<RemoteData<T>> {
+    const requestId = this.requestService.generateRequestId();
+    const serializedObject = new DSpaceSerializer(getClassForType(object.type)).serialize(object);
+
+    endpoint$.pipe(
+      take(1),
+    ).subscribe((endpoint: string) => {
+      const request = new CreateRequest(requestId, endpoint, JSON.stringify(serializedObject));
+      if (hasValue(this.responseMsToLive)) {
+        request.responseMsToLive = this.responseMsToLive;
+      }
+      this.requestService.send(request);
+    });
+
+    const result$ = this.rdbService.buildFromRequestUUID<T>(requestId);
+
+    // TODO a dataservice is not the best place to show a notification,
+    // this should move up to the components that use this method
+    result$.pipe(
+      takeWhile((rd: RemoteData<T>) => rd.isLoading, true)
+    ).subscribe((rd: RemoteData<T>) => {
+      if (rd.hasFailed) {
+        this.notificationsService.error('Server Error:', rd.errorMessage, new NotificationOptions(-1));
+      }
+    });
+
+    return result$;
+  }
+}

src/app/core/data/base/data-service.decorator.spec.ts

@@ -0,0 +1,55 @@
+/* eslint-disable max-classes-per-file */
+/**
+ * The contents of this file are subject to the license and copyright
+ * detailed in the LICENSE and NOTICE files at the root of the source
+ * tree and available online at
+ *
+ * http://www.dspace.org/license/
+ */
+import { ResourceType } from '../../shared/resource-type';
+import { BaseDataService } from './base-data.service';
+import { HALDataService } from './hal-data-service.interface';
+import { dataService, getDataServiceFor } from './data-service.decorator';
+
+class TestService extends BaseDataService<any> {
+}
+
+class AnotherTestService implements HALDataService<any> {
+  public findListByHref(href$, findListOptions, useCachedVersionIfAvailable, reRequestOnStale, ...linksToFollow): any {
+    return undefined;
+  }
+
+  public findByHref(href$, useCachedVersionIfAvailable, reRequestOnStale, ...linksToFollow): any {
+    return undefined;
+  }
+}
+
+let testType;
+
+describe('@dataService/getDataServiceFor', () => {
+  beforeEach(() => {
+    testType = new ResourceType('testType-' + new Date().getTime());
+  });
+
+  it('should register a resourcetype for a dataservice', () => {
+    dataService(testType)(TestService);
+    expect(getDataServiceFor(testType)).toBe(TestService);
+  });
+
+  describe(`when the resource type isn't specified`, () => {
+    it(`should throw an error`, () => {
+      expect(() => {
+        dataService(undefined)(TestService);
+      }).toThrow();
+    });
+  });
+
+  describe(`when there already is a registered dataservice for a resourcetype`, () => {
+    it(`should throw an error`, () => {
+      dataService(testType)(TestService);
+      expect(() => {
+        dataService(testType)(AnotherTestService);
+      }).toThrow();
+    });
+  });
+});

src/app/core/data/base/data-service.decorator.ts

@@ -0,0 +1,51 @@
+/**
+ * The contents of this file are subject to the license and copyright
+ * detailed in the LICENSE and NOTICE files at the root of the source
+ * tree and available online at
+ *
+ * http://www.dspace.org/license/
+ */
+import { InjectionToken } from '@angular/core';
+import { CacheableObject } from '../../cache/cacheable-object.model';
+import { ResourceType } from '../../shared/resource-type';
+import { GenericConstructor } from '../../shared/generic-constructor';
+import { hasNoValue, hasValue } from '../../../shared/empty.util';
+import { HALDataService } from './hal-data-service.interface';
+
+export const DATA_SERVICE_FACTORY = new InjectionToken<(resourceType: ResourceType) => GenericConstructor<HALDataService<any>>>('getDataServiceFor', {
+  providedIn: 'root',
+  factory: () => getDataServiceFor,
+});
+const dataServiceMap = new Map();
+
+/**
+ * A class decorator to indicate that this class is a data service for a given HAL resource type.
+ *
+ * In most cases, a data service should extend {@link BaseDataService}.
+ * At the very least it must implement {@link HALDataService} in order for it to work with {@link LinkService}.
+ *
+ * @param resourceType the resource type the class is a dataservice for
+ */
+export function dataService(resourceType: ResourceType) {
+  return (target: GenericConstructor<HALDataService<any>>): void => {
+    if (hasNoValue(resourceType)) {
+      throw new Error(`Invalid @dataService annotation on ${target}, resourceType needs to be defined`);
+    }
+    const existingDataservice = dataServiceMap.get(resourceType.value);
+
+    if (hasValue(existingDataservice)) {
+      throw new Error(`Multiple dataservices for ${resourceType.value}: ${existingDataservice} and ${target}`);
+    }
+
+    dataServiceMap.set(resourceType.value, target);
+  };
+}
+
+/**
+ * Return the dataservice matching the given resource type
+ *
+ * @param resourceType the resource type you want the matching dataservice for
+ */
+export function getDataServiceFor<T extends CacheableObject>(resourceType: ResourceType): GenericConstructor<HALDataService<any>> {
+  return dataServiceMap.get(resourceType.value);
+}

src/app/core/data/base/delete-data.spec.ts

@@ -0,0 +1,245 @@
+/**
+ * The contents of this file are subject to the license and copyright
+ * detailed in the LICENSE and NOTICE files at the root of the source
+ * tree and available online at
+ *
+ * http://www.dspace.org/license/
+ */
+import { constructIdEndpointDefault } from './identifiable-data.service';
+import { RequestService } from '../request.service';
+import { RemoteDataBuildService } from '../../cache/builders/remote-data-build.service';
+import { ObjectCacheService } from '../../cache/object-cache.service';
+import { HALEndpointService } from '../../shared/hal-endpoint.service';
+import { FindListOptions } from '../find-list-options.model';
+import { Observable, of as observableOf } from 'rxjs';
+import { getMockRequestService } from '../../../shared/mocks/request.service.mock';
+import { HALEndpointServiceStub } from '../../../shared/testing/hal-endpoint-service.stub';
+import { getMockRemoteDataBuildService } from '../../../shared/mocks/remote-data-build.service.mock';
+import { followLink } from '../../../shared/utils/follow-link-config.model';
+import { TestScheduler } from 'rxjs/testing';
+import { RemoteData } from '../remote-data';
+import { RequestEntryState } from '../request-entry-state.model';
+import { DeleteData, DeleteDataImpl } from './delete-data';
+import { NotificationsService } from '../../../shared/notifications/notifications.service';
+import { createFailedRemoteDataObject, createSuccessfulRemoteDataObject, createSuccessfulRemoteDataObject$ } from '../../../shared/remote-data.utils';
+import { fakeAsync, tick } from '@angular/core/testing';
+
+/**
+ * Tests whether calls to `DeleteData` methods are correctly patched through in a concrete data service that implements it
+ */
+export function testDeleteDataImplementation(serviceFactory: () => DeleteData<any>) {
+  let service;
+
+  describe('DeleteData implementation', () => {
+    const ID = '2ce78f3a-791b-4d70-b5eb-753d587bbadd';
+    const HREF = 'https://rest.api/core/items/' + ID;
+    const COPY_VIRTUAL_METADATA = [
+      'a', 'b', 'c'
+    ];
+
+    beforeAll(() => {
+      service = serviceFactory();
+      (service as any).deleteData = jasmine.createSpyObj('deleteData', {
+        delete: 'TEST delete',
+        deleteByHref: 'TEST deleteByHref',
+      });
+    });
+
+    it('should handle calls to delete', () => {
+      const out: any = service.delete(ID, COPY_VIRTUAL_METADATA);
+
+      expect((service as any).deleteData.delete).toHaveBeenCalledWith(ID, COPY_VIRTUAL_METADATA);
+      expect(out).toBe('TEST delete');
+    });
+
+    it('should handle calls to deleteByHref', () => {
+      const out: any = service.deleteByHref(HREF, COPY_VIRTUAL_METADATA);
+
+      expect((service as any).deleteData.deleteByHref).toHaveBeenCalledWith(HREF, COPY_VIRTUAL_METADATA);
+      expect(out).toBe('TEST deleteByHref');
+    });
+  });
+}
+
+const endpoint = 'https://rest.api/core';
+
+const BOOLEAN = { f: false, t: true };
+
+class TestService extends DeleteDataImpl<any> {
+  constructor(
+    protected requestService: RequestService,
+    protected rdbService: RemoteDataBuildService,
+    protected objectCache: ObjectCacheService,
+    protected halService: HALEndpointService,
+    protected notificationsService: NotificationsService,
+  ) {
+    super(undefined, requestService, rdbService, objectCache, halService, notificationsService, undefined, constructIdEndpointDefault);
+  }
+
+  public getBrowseEndpoint(options: FindListOptions = {}, linkPath: string = this.linkPath): Observable<string> {
+    return observableOf(endpoint);
+  }
+}
+
+describe('DeleteDataImpl', () => {
+  let service: TestService;
+  let requestService;
+  let halService;
+  let rdbService;
+  let objectCache;
+  let notificationsService;
+  let selfLink;
+  let linksToFollow;
+  let testScheduler;
+  let remoteDataMocks;
+
+  function initTestService(): TestService {
+    requestService = getMockRequestService();
+    halService = new HALEndpointServiceStub('url') as any;
+    rdbService = getMockRemoteDataBuildService();
+    objectCache = {
+
+      addPatch: () => {
+        /* empty */
+      },
+      getObjectBySelfLink: () => {
+        /* empty */
+      },
+      getByHref: () => {
+        /* empty */
+      }
+    } as any;
+    notificationsService = {} as NotificationsService;
+    selfLink = 'https://rest.api/endpoint/1698f1d3-be98-4c51-9fd8-6bfedcbd59b7';
+    linksToFollow = [
+      followLink('a'),
+      followLink('b')
+    ];
+
+    testScheduler = new TestScheduler((actual, expected) => {
+      // asserting the two objects are equal
+      // e.g. using chai.
+      expect(actual).toEqual(expected);
+    });
+
+    const timeStamp = new Date().getTime();
+    const msToLive = 15 * 60 * 1000;
+    const payload = { foo: 'bar' };
+    const statusCodeSuccess = 200;
+    const statusCodeError = 404;
+    const errorMessage = 'not found';
+    remoteDataMocks = {
+      RequestPending: new RemoteData(undefined, msToLive, timeStamp, RequestEntryState.RequestPending, undefined, undefined, undefined),
+      ResponsePending: new RemoteData(undefined, msToLive, timeStamp, RequestEntryState.ResponsePending, undefined, undefined, undefined),
+      Success: new RemoteData(timeStamp, msToLive, timeStamp, RequestEntryState.Success, undefined, payload, statusCodeSuccess),
+      SuccessStale: new RemoteData(timeStamp, msToLive, timeStamp, RequestEntryState.SuccessStale, undefined, payload, statusCodeSuccess),
+      Error: new RemoteData(timeStamp, msToLive, timeStamp, RequestEntryState.Error, errorMessage, undefined, statusCodeError),
+      ErrorStale: new RemoteData(timeStamp, msToLive, timeStamp, RequestEntryState.ErrorStale, errorMessage, undefined, statusCodeError),
+    };
+
+    return new TestService(
+      requestService,
+      rdbService,
+      objectCache,
+      halService,
+      notificationsService,
+    );
+  }
+
+  beforeEach(() => {
+    service = initTestService();
+  });
+
+  describe('delete', () => {
+    let MOCK_SUCCEEDED_RD;
+    let MOCK_FAILED_RD;
+
+    let invalidateByHrefSpy: jasmine.Spy;
+    let buildFromRequestUUIDSpy: jasmine.Spy;
+    let getIDHrefObsSpy: jasmine.Spy;
+    let deleteByHrefSpy: jasmine.Spy;
+
+    beforeEach(() => {
+      invalidateByHrefSpy = spyOn(service, 'invalidateByHref').and.returnValue(observableOf(true));
+      buildFromRequestUUIDSpy = spyOn(rdbService, 'buildFromRequestUUID').and.callThrough();
+      getIDHrefObsSpy = spyOn(service, 'getIDHrefObs').and.callThrough();
+      deleteByHrefSpy = spyOn(service, 'deleteByHref').and.callThrough();
+
+      MOCK_SUCCEEDED_RD = createSuccessfulRemoteDataObject({});
+      MOCK_FAILED_RD = createFailedRemoteDataObject('something went wrong');
+    });
+
+    it('should retrieve href by ID and call deleteByHref', () => {
+      getIDHrefObsSpy.and.returnValue(observableOf('some-href'));
+      buildFromRequestUUIDSpy.and.returnValue(createSuccessfulRemoteDataObject$({}));
+
+      service.delete('some-id', ['a', 'b', 'c']).subscribe(rd => {
+        expect(getIDHrefObsSpy).toHaveBeenCalledWith('some-id');
+        expect(deleteByHrefSpy).toHaveBeenCalledWith('some-href', ['a', 'b', 'c']);
+      });
+    });
+
+    describe('deleteByHref', () => {
+      it('should call invalidateByHref if the DELETE request succeeds', (done) => {
+        buildFromRequestUUIDSpy.and.returnValue(observableOf(MOCK_SUCCEEDED_RD));
+
+        service.deleteByHref('some-href').subscribe(rd => {
+          expect(rd).toBe(MOCK_SUCCEEDED_RD);
+          expect(invalidateByHrefSpy).toHaveBeenCalled();
+          done();
+        });
+      });
+
+      it('should call invalidateByHref even if not subscribing to returned Observable', fakeAsync(() => {
+        buildFromRequestUUIDSpy.and.returnValue(observableOf(MOCK_SUCCEEDED_RD));
+
+        service.deleteByHref('some-href');
+        tick();
+
+        expect(invalidateByHrefSpy).toHaveBeenCalled();
+      }));
+
+      it('should not call invalidateByHref if the DELETE request fails', (done) => {
+        buildFromRequestUUIDSpy.and.returnValue(observableOf(MOCK_FAILED_RD));
+
+        service.deleteByHref('some-href').subscribe(rd => {
+          expect(rd).toBe(MOCK_FAILED_RD);
+          expect(invalidateByHrefSpy).not.toHaveBeenCalled();
+          done();
+        });
+      });
+
+      it('should wait for invalidateByHref before emitting', () => {
+        testScheduler.run(({ cold, expectObservable }) => {
+          buildFromRequestUUIDSpy.and.returnValue(
+            cold('(r|)', { r: MOCK_SUCCEEDED_RD})      // RD emits right away
+          );
+          invalidateByHrefSpy.and.returnValue(
+            cold('----(t|)', BOOLEAN)                  // but we pretend that setting requests to stale takes longer
+          );
+
+          const done$ = service.deleteByHref('some-href');
+          expectObservable(done$).toBe(
+            '----(r|)', { r: MOCK_SUCCEEDED_RD}        // ...and expect the returned Observable to wait until that's done
+          );
+        });
+      });
+
+      it('should wait for the DELETE request to resolve before emitting', () => {
+        testScheduler.run(({ cold, expectObservable }) => {
+          buildFromRequestUUIDSpy.and.returnValue(
+            cold('----(r|)', { r: MOCK_SUCCEEDED_RD})   // the request takes a while
+          );
+          invalidateByHrefSpy.and.returnValue(
+            cold('(t|)', BOOLEAN)                       // but we pretend that setting to stale happens sooner
+          );                                            // e.g.: maybe already stale before this call?
+
+          const done$ = service.deleteByHref('some-href');
+          expectObservable(done$).toBe(
+            '----(r|)', { r: MOCK_SUCCEEDED_RD}         // ...and expect the returned Observable to wait for the request
+          );
+        });
+      });
+    });
+  });
+});

src/app/core/data/base/delete-data.ts

@@ -0,0 +1,108 @@
+/**
+ * The contents of this file are subject to the license and copyright
+ * detailed in the LICENSE and NOTICE files at the root of the source
+ * tree and available online at
+ *
+ * http://www.dspace.org/license/
+ */
+import { CacheableObject } from '../../cache/cacheable-object.model';
+import { AsyncSubject, combineLatest, Observable } from 'rxjs';
+import { RemoteData } from '../remote-data';
+import { NoContent } from '../../shared/NoContent.model';
+import { filter, map, switchMap } from 'rxjs/operators';
+import { DeleteRequest } from '../request.models';
+import { hasNoValue, hasValue } from '../../../shared/empty.util';
+import { getFirstCompletedRemoteData } from '../../shared/operators';
+import { RequestService } from '../request.service';
+import { RemoteDataBuildService } from '../../cache/builders/remote-data-build.service';
+import { HALEndpointService } from '../../shared/hal-endpoint.service';
+import { NotificationsService } from '../../../shared/notifications/notifications.service';
+import { ObjectCacheService } from '../../cache/object-cache.service';
+import { ConstructIdEndpoint, IdentifiableDataService } from './identifiable-data.service';
+
+export interface DeleteData<T extends CacheableObject> {
+  /**
+   * Delete an existing object on the server
+   * @param   objectId The id of the object to be removed
+   * @param   copyVirtualMetadata (optional parameter) the identifiers of the relationship types for which the virtual
+   *                            metadata should be saved as real metadata
+   * @return  A RemoteData observable with an empty payload, but still representing the state of the request: statusCode,
+   *          errorMessage, timeCompleted, etc
+   */
+  delete(objectId: string, copyVirtualMetadata?: string[]): Observable<RemoteData<NoContent>>;
+
+  /**
+   * Delete an existing object on the server
+   * @param   href The self link of the object to be removed
+   * @param   copyVirtualMetadata (optional parameter) the identifiers of the relationship types for which the virtual
+   *                            metadata should be saved as real metadata
+   * @return  A RemoteData observable with an empty payload, but still representing the state of the request: statusCode,
+   *          errorMessage, timeCompleted, etc
+   *          Only emits once all request related to the DSO has been invalidated.
+   */
+  deleteByHref(href: string, copyVirtualMetadata?: string[]): Observable<RemoteData<NoContent>>;
+}
+
+export class DeleteDataImpl<T extends CacheableObject> extends IdentifiableDataService<T> implements DeleteData<T> {
+  constructor(
+    protected linkPath: string,
+    protected requestService: RequestService,
+    protected rdbService: RemoteDataBuildService,
+    protected objectCache: ObjectCacheService,
+    protected halService: HALEndpointService,
+    protected notificationsService: NotificationsService,
+    protected responseMsToLive: number,
+    protected constructIdEndpoint: ConstructIdEndpoint,
+  ) {
+    super(linkPath, requestService, rdbService, objectCache, halService, responseMsToLive, constructIdEndpoint);
+    if (hasNoValue(constructIdEndpoint)) {
+      throw new Error(`DeleteDataImpl initialized without a constructIdEndpoint method (linkPath: ${linkPath})`);
+    }
+  }
+
+  delete(objectId: string, copyVirtualMetadata?: string[]): Observable<RemoteData<NoContent>> {
+    return this.getIDHrefObs(objectId).pipe(
+      switchMap((href: string) => this.deleteByHref(href, copyVirtualMetadata)),
+    );
+  }
+
+  deleteByHref(href: string, copyVirtualMetadata?: string[]): Observable<RemoteData<NoContent>> {
+    const requestId = this.requestService.generateRequestId();
+
+    if (copyVirtualMetadata) {
+      copyVirtualMetadata.forEach((id) =>
+        href += (href.includes('?') ? '&' : '?')
+          + 'copyVirtualMetadata='
+          + id,
+      );
+    }
+
+    const request = new DeleteRequest(requestId, href);
+    if (hasValue(this.responseMsToLive)) {
+      request.responseMsToLive = this.responseMsToLive;
+    }
+    this.requestService.send(request);
+
+    const response$ = this.rdbService.buildFromRequestUUID(requestId);
+
+    const invalidated$ = new AsyncSubject<boolean>();
+    response$.pipe(
+      getFirstCompletedRemoteData(),
+      switchMap((rd: RemoteData<NoContent>) => {
+        if (rd.hasSucceeded) {
+          return this.invalidateByHref(href);
+        } else {
+          return [true];
+        }
+      })
+    ).subscribe(() => {
+      invalidated$.next(true);
+      invalidated$.complete();
+    });
+
+    return combineLatest([response$, invalidated$]).pipe(
+      filter(([_, invalidated]) => invalidated),
+      map(([response, _]) => response),
+    );
+  }
+}

src/app/core/data/base/find-all-data.spec.ts

@@ -0,0 +1,296 @@
+/**
+ * The contents of this file are subject to the license and copyright
+ * detailed in the LICENSE and NOTICE files at the root of the source
+ * tree and available online at
+ *
+ * http://www.dspace.org/license/
+ */
+import { FindAllData, FindAllDataImpl } from './find-all-data';
+import { FindListOptions } from '../find-list-options.model';
+import { followLink } from '../../../shared/utils/follow-link-config.model';
+import { getMockRequestService } from '../../../shared/mocks/request.service.mock';
+import { HALEndpointServiceStub } from '../../../shared/testing/hal-endpoint-service.stub';
+import { getMockRemoteDataBuildService } from '../../../shared/mocks/remote-data-build.service.mock';
+import { TestScheduler } from 'rxjs/testing';
+import { RemoteData } from '../remote-data';
+import { RequestEntryState } from '../request-entry-state.model';
+import { SortDirection, SortOptions } from '../../cache/models/sort-options.model';
+import { RequestParam } from '../../cache/models/request-param.model';
+
+import { RequestService } from '../request.service';
+import { RemoteDataBuildService } from '../../cache/builders/remote-data-build.service';
+import { HALEndpointService } from '../../shared/hal-endpoint.service';
+import { ObjectCacheService } from '../../cache/object-cache.service';
+import { Observable, of as observableOf } from 'rxjs';
+
+/**
+ * Tests whether calls to `FindAllData` methods are correctly patched through in a concrete data service that implements it
+ */
+export function testFindAllDataImplementation(serviceFactory: () => FindAllData<any>) {
+  let service;
+
+  describe('FindAllData implementation', () => {
+    const OPTIONS = Object.assign(new FindListOptions(), { elementsPerPage: 10, currentPage: 3 });
+    const FOLLOWLINKS = [
+      followLink('test'),
+      followLink('something'),
+    ];
+
+    beforeAll(() => {
+      service = serviceFactory();
+      (service as any).findAllData =  jasmine.createSpyObj('findAllData', {
+        findAll: 'TEST findAll',
+      });
+    });
+
+    it('should handle calls to findAll', () => {
+      const out: any = service.findAll(OPTIONS, false, true, ...FOLLOWLINKS);
+
+      expect((service as any).findAllData.findAll).toHaveBeenCalledWith(OPTIONS, false, true, ...FOLLOWLINKS);
+      expect(out).toBe('TEST findAll');
+    });
+  });
+}
+
+const endpoint = 'https://rest.api/core';
+
+class TestService extends FindAllDataImpl<any> {
+  constructor(
+    protected requestService: RequestService,
+    protected rdbService: RemoteDataBuildService,
+    protected objectCache: ObjectCacheService,
+    protected halService: HALEndpointService,
+  ) {
+    super(undefined, requestService, rdbService, objectCache, halService, undefined);
+  }
+
+  public getBrowseEndpoint(options: FindListOptions = {}, linkPath: string = this.linkPath): Observable<string> {
+    return observableOf(endpoint);
+  }
+}
+
+describe('FindAllDataImpl', () => {
+  let service: TestService;
+  let options: FindListOptions;
+  let requestService;
+  let halService;
+  let rdbService;
+  let objectCache;
+  let selfLink;
+  let linksToFollow;
+  let testScheduler;
+  let remoteDataMocks;
+
+  function initTestService(): TestService {
+    requestService = getMockRequestService();
+    halService = new HALEndpointServiceStub('url') as any;
+    rdbService = getMockRemoteDataBuildService();
+    objectCache = {
+
+      addPatch: () => {
+        /* empty */
+      },
+      getObjectBySelfLink: () => {
+        /* empty */
+      },
+      getByHref: () => {
+        /* empty */
+      },
+    } as any;
+    selfLink = 'https://rest.api/endpoint/1698f1d3-be98-4c51-9fd8-6bfedcbd59b7';
+    linksToFollow = [
+      followLink('a'),
+      followLink('b'),
+    ];
+
+    testScheduler = new TestScheduler((actual, expected) => {
+      // asserting the two objects are equal
+      // e.g. using chai.
+      expect(actual).toEqual(expected);
+    });
+
+    const timeStamp = new Date().getTime();
+    const msToLive = 15 * 60 * 1000;
+    const payload = { foo: 'bar' };
+    const statusCodeSuccess = 200;
+    const statusCodeError = 404;
+    const errorMessage = 'not found';
+    remoteDataMocks = {
+      RequestPending: new RemoteData(undefined, msToLive, timeStamp, RequestEntryState.RequestPending, undefined, undefined, undefined),
+      ResponsePending: new RemoteData(undefined, msToLive, timeStamp, RequestEntryState.ResponsePending, undefined, undefined, undefined),
+      Success: new RemoteData(timeStamp, msToLive, timeStamp, RequestEntryState.Success, undefined, payload, statusCodeSuccess),
+      SuccessStale: new RemoteData(timeStamp, msToLive, timeStamp, RequestEntryState.SuccessStale, undefined, payload, statusCodeSuccess),
+      Error: new RemoteData(timeStamp, msToLive, timeStamp, RequestEntryState.Error, errorMessage, undefined, statusCodeError),
+      ErrorStale: new RemoteData(timeStamp, msToLive, timeStamp, RequestEntryState.ErrorStale, errorMessage, undefined, statusCodeError),
+    };
+
+    return new TestService(
+      requestService,
+      rdbService,
+      objectCache,
+      halService,
+    );
+  }
+
+  beforeEach(() => {
+    service = initTestService();
+  });
+
+  describe('getFindAllHref', () => {
+
+    it('should return an observable with the endpoint', () => {
+      options = {};
+
+      (service as any).getFindAllHref(options).subscribe((value) => {
+          expect(value).toBe(endpoint);
+        },
+      );
+    });
+
+    it('should include page in href if currentPage provided in options', () => {
+      options = { currentPage: 2 };
+      const expected = `${endpoint}?page=${options.currentPage - 1}`;
+
+      (service as any).getFindAllHref(options).subscribe((value) => {
+        expect(value).toBe(expected);
+      });
+    });
+
+    it('should include size in href if elementsPerPage provided in options', () => {
+      options = { elementsPerPage: 5 };
+      const expected = `${endpoint}?size=${options.elementsPerPage}`;
+
+      (service as any).getFindAllHref(options).subscribe((value) => {
+        expect(value).toBe(expected);
+      });
+    });
+
+    it('should include sort href if SortOptions provided in options', () => {
+      const sortOptions = new SortOptions('field1', SortDirection.ASC);
+      options = { sort: sortOptions };
+      const expected = `${endpoint}?sort=${sortOptions.field},${sortOptions.direction}`;
+
+      (service as any).getFindAllHref(options).subscribe((value) => {
+        expect(value).toBe(expected);
+      });
+    });
+
+    it('should include startsWith in href if startsWith provided in options', () => {
+      options = { startsWith: 'ab' };
+      const expected = `${endpoint}?startsWith=${options.startsWith}`;
+
+      (service as any).getFindAllHref(options).subscribe((value) => {
+        expect(value).toBe(expected);
+      });
+    });
+
+    it('should include all provided options in href', () => {
+      const sortOptions = new SortOptions('field1', SortDirection.DESC);
+      options = {
+        currentPage: 6,
+        elementsPerPage: 10,
+        sort: sortOptions,
+        startsWith: 'ab',
+
+      };
+      const expected = `${endpoint}?page=${options.currentPage - 1}&size=${options.elementsPerPage}` +
+        `&sort=${sortOptions.field},${sortOptions.direction}&startsWith=${options.startsWith}`;
+
+      (service as any).getFindAllHref(options).subscribe((value) => {
+        expect(value).toBe(expected);
+      });
+    });
+
+    it('should include all searchParams in href if any provided in options', () => {
+      options = {
+        searchParams: [
+          new RequestParam('param1', 'test'),
+          new RequestParam('param2', 'test2'),
+        ],
+      };
+      const expected = `${endpoint}?param1=test&param2=test2`;
+
+      (service as any).getFindAllHref(options).subscribe((value) => {
+        expect(value).toBe(expected);
+      });
+    });
+
+    it('should include linkPath in href if any provided', () => {
+      const expected = `${endpoint}/test/entries`;
+
+      (service as any).getFindAllHref({}, 'test/entries').subscribe((value) => {
+        expect(value).toBe(expected);
+      });
+    });
+
+    it('should include single linksToFollow as embed', () => {
+      const expected = `${endpoint}?embed=bundles`;
+
+      (service as any).getFindAllHref({}, null, followLink('bundles')).subscribe((value) => {
+        expect(value).toBe(expected);
+      });
+    });
+
+    it('should include single linksToFollow as embed and its size', () => {
+      const expected = `${endpoint}?embed.size=bundles=5&embed=bundles`;
+      const config: FindListOptions = Object.assign(new FindListOptions(), {
+        elementsPerPage: 5,
+      });
+      (service as any).getFindAllHref({}, null, followLink('bundles', { findListOptions: config })).subscribe((value) => {
+        expect(value).toBe(expected);
+      });
+    });
+
+    it('should include multiple linksToFollow as embed', () => {
+      const expected = `${endpoint}?embed=bundles&embed=owningCollection&embed=templateItemOf`;
+
+      (service as any).getFindAllHref({}, null, followLink('bundles'), followLink('owningCollection'), followLink('templateItemOf')).subscribe((value) => {
+        expect(value).toBe(expected);
+      });
+    });
+
+    it('should include multiple linksToFollow as embed and its sizes if given', () => {
+      const expected = `${endpoint}?embed=bundles&embed.size=owningCollection=2&embed=owningCollection&embed=templateItemOf`;
+
+      const config: FindListOptions = Object.assign(new FindListOptions(), {
+        elementsPerPage: 2,
+      });
+
+      (service as any).getFindAllHref({}, null, followLink('bundles'), followLink('owningCollection', { findListOptions: config }), followLink('templateItemOf')).subscribe((value) => {
+        expect(value).toBe(expected);
+      });
+    });
+
+    it('should not include linksToFollow with shouldEmbed = false', () => {
+      const expected = `${endpoint}?embed=templateItemOf`;
+
+      (service as any).getFindAllHref(
+        {},
+        null,
+        followLink('bundles', { shouldEmbed: false }),
+        followLink('owningCollection', { shouldEmbed: false }),
+        followLink('templateItemOf'),
+      ).subscribe((value) => {
+        expect(value).toBe(expected);
+      });
+    });
+
+    it('should include nested linksToFollow 3lvl', () => {
+      const expected = `${endpoint}?embed=owningCollection/itemtemplate/relationships`;
+
+      (service as any).getFindAllHref({}, null, followLink('owningCollection', {}, followLink('itemtemplate', {}, followLink('relationships')))).subscribe((value) => {
+        expect(value).toBe(expected);
+      });
+    });
+
+    it('should include nested linksToFollow 2lvl and nested embed\'s size', () => {
+      const expected = `${endpoint}?embed.size=owningCollection/itemtemplate=4&embed=owningCollection/itemtemplate`;
+      const config: FindListOptions = Object.assign(new FindListOptions(), {
+        elementsPerPage: 4,
+      });
+      (service as any).getFindAllHref({}, null, followLink('owningCollection', {}, followLink('itemtemplate', { findListOptions: config }))).subscribe((value) => {
+        expect(value).toBe(expected);
+      });
+    });
+  });
+});

src/app/core/data/base/find-all-data.ts

@@ -0,0 +1,101 @@
+/**
+ * The contents of this file are subject to the license and copyright
+ * detailed in the LICENSE and NOTICE files at the root of the source
+ * tree and available online at
+ *
+ * http://www.dspace.org/license/
+ */
+
+import { Observable } from 'rxjs';
+import { FindListOptions } from '../find-list-options.model';
+import { FollowLinkConfig } from '../../../shared/utils/follow-link-config.model';
+import { RemoteData } from '../remote-data';
+import { PaginatedList } from '../paginated-list.model';
+import { CacheableObject } from '../../cache/cacheable-object.model';
+import { BaseDataService } from './base-data.service';
+import { distinctUntilChanged, filter, map } from 'rxjs/operators';
+import { isNotEmpty } from '../../../shared/empty.util';
+import { RequestService } from '../request.service';
+import { RemoteDataBuildService } from '../../cache/builders/remote-data-build.service';
+import { ObjectCacheService } from '../../cache/object-cache.service';
+import { HALEndpointService } from '../../shared/hal-endpoint.service';
+
+/**
+ * Interface for a data service that list all of its objects.
+ */
+export interface FindAllData<T extends CacheableObject> {
+  /**
+   * Returns {@link RemoteData} of all object with a list of {@link FollowLinkConfig}, to indicate which embedded
+   * info should be added to the objects
+   *
+   * @param options                     Find list options object
+   * @param useCachedVersionIfAvailable If this is true, the request will only be sent if there's
+   *                                    no valid cached version. Defaults to true
+   * @param reRequestOnStale            Whether or not the request should automatically be re-
+   *                                    requested after the response becomes stale
+   * @param linksToFollow               List of {@link FollowLinkConfig} that indicate which
+   *                                    {@link HALLink}s should be automatically resolved
+   * @return {Observable<RemoteData<PaginatedList<T>>>}
+   *    Return an observable that emits object list
+   */
+  findAll(options?: FindListOptions, useCachedVersionIfAvailable?: boolean, reRequestOnStale?: boolean, ...linksToFollow: FollowLinkConfig<T>[]): Observable<RemoteData<PaginatedList<T>>>;
+}
+
+/**
+ * A DataService feature to list all objects.
+ *
+ * Concrete data services can use this feature by implementing {@link FindAllData}
+ * and delegating its method to an inner instance of this class.
+ */
+export class FindAllDataImpl<T extends CacheableObject> extends BaseDataService<T> implements FindAllData<T> {
+  constructor(
+    protected linkPath: string,
+    protected requestService: RequestService,
+    protected rdbService: RemoteDataBuildService,
+    protected objectCache: ObjectCacheService,
+    protected halService: HALEndpointService,
+    protected responseMsToLive: number,
+  ) {
+    super(linkPath, requestService, rdbService, objectCache, halService, responseMsToLive);
+  }
+
+  /**
+   * Returns {@link RemoteData} of all object with a list of {@link FollowLinkConfig}, to indicate which embedded
+   * info should be added to the objects
+   *
+   * @param options                     Find list options object
+   * @param useCachedVersionIfAvailable If this is true, the request will only be sent if there's
+   *                                    no valid cached version. Defaults to true
+   * @param reRequestOnStale            Whether or not the request should automatically be re-
+   *                                    requested after the response becomes stale
+   * @param linksToFollow               List of {@link FollowLinkConfig} that indicate which
+   *                                    {@link HALLink}s should be automatically resolved
+   * @return {Observable<RemoteData<PaginatedList<T>>>}
+   *    Return an observable that emits object list
+   */
+  findAll(options: FindListOptions = {}, useCachedVersionIfAvailable = true, reRequestOnStale = true, ...linksToFollow: FollowLinkConfig<T>[]): Observable<RemoteData<PaginatedList<T>>> {
+    return this.findListByHref(this.getFindAllHref(options), options, useCachedVersionIfAvailable, reRequestOnStale, ...linksToFollow);
+  }
+
+  /**
+   * Create the HREF with given options object
+   *
+   * @param options The [[FindListOptions]] object
+   * @param linkPath The link path for the object
+   * @return {Observable<string>}
+   *    Return an observable that emits created HREF
+   * @param linksToFollow   List of {@link FollowLinkConfig} that indicate which {@link HALLink}s should be automatically resolved
+   */
+  getFindAllHref(options: FindListOptions = {}, linkPath?: string, ...linksToFollow: FollowLinkConfig<T>[]): Observable<string> {
+    let endpoint$: Observable<string>;
+    const args = [];
+
+    endpoint$ = this.getBrowseEndpoint(options).pipe(
+      filter((href: string) => isNotEmpty(href)),
+      map((href: string) => isNotEmpty(linkPath) ? `${href}/${linkPath}` : href),
+      distinctUntilChanged(),
+    );
+
+    return endpoint$.pipe(map((result: string) => this.buildHrefFromFindOptions(result, options, args, ...linksToFollow)));
+  }
+}

src/app/core/data/base/hal-data-service.interface.ts

@@ -0,0 +1,41 @@
+/**
+ * The contents of this file are subject to the license and copyright
+ * detailed in the LICENSE and NOTICE files at the root of the source
+ * tree and available online at
+ *
+ * http://www.dspace.org/license/
+ */
+import { Observable } from 'rxjs';
+import { FollowLinkConfig } from '../../../shared/utils/follow-link-config.model';
+import { RemoteData } from '../remote-data';
+import { FindListOptions } from '../find-list-options.model';
+import { PaginatedList } from '../paginated-list.model';
+import { HALResource } from '../../shared/hal-resource.model';
+
+/**
+ * An interface defining the minimum functionality needed for a data service to resolve HAL resources.
+ */
+export interface HALDataService<T extends HALResource> {
+  /**
+   * Returns an Observable of {@link RemoteData} of an object, based on an href,
+   * with a list of {@link FollowLinkConfig}, to automatically resolve {@link HALLink}s of the object
+   *
+   * @param href$                       The url of object we want to retrieve. Can be a string or an Observable<string>
+   * @param useCachedVersionIfAvailable If this is true, the request will only be sent if there's no valid cached version.
+   * @param reRequestOnStale            Whether or not the request should automatically be re-requested after the response becomes stale
+   * @param linksToFollow               List of {@link FollowLinkConfig} that indicate which {@link HALLink}s should be automatically resolved
+   */
+  findByHref(href$: string | Observable<string>, useCachedVersionIfAvailable?: boolean, reRequestOnStale?: boolean, ...linksToFollow: FollowLinkConfig<T>[]): Observable<RemoteData<T>>;
+
+  /**
+   * Returns an Observable of a {@link RemoteData} of a {@link PaginatedList} of objects, based on an href,
+   * with a list of {@link FollowLinkConfig}, to automatically resolve {@link HALLink}s of the object
+   *
+   * @param href$                       The url of list we want to retrieve. Can be a string or an Observable<string>
+   * @param findListOptions             The options for to use for this find list request.
+   * @param useCachedVersionIfAvailable If this is true, the request will only be sent if there's no valid cached version.
+   * @param reRequestOnStale            Whether or not the request should automatically be re-requested after the response becomes stale
+   * @param linksToFollow               List of {@link FollowLinkConfig} that indicate which {@link HALLink}s should be automatically resolved
+   */
+  findListByHref(href$: string | Observable<string>, findListOptions?: FindListOptions, useCachedVersionIfAvailable?: boolean, reRequestOnStale?: boolean, ...linksToFollow: FollowLinkConfig<T>[]): Observable<RemoteData<PaginatedList<T>>>;
+}

src/app/core/data/base/identifiable-data.service.spec.ts

@@ -0,0 +1,145 @@
+/**
+ * The contents of this file are subject to the license and copyright
+ * detailed in the LICENSE and NOTICE files at the root of the source
+ * tree and available online at
+ *
+ * http://www.dspace.org/license/
+ */
+import { FindListOptions } from '../find-list-options.model';
+import { getMockRequestService } from '../../../shared/mocks/request.service.mock';
+import { HALEndpointServiceStub } from '../../../shared/testing/hal-endpoint-service.stub';
+import { getMockRemoteDataBuildService } from '../../../shared/mocks/remote-data-build.service.mock';
+import { followLink } from '../../../shared/utils/follow-link-config.model';
+import { TestScheduler } from 'rxjs/testing';
+import { RemoteData } from '../remote-data';
+import { RequestEntryState } from '../request-entry-state.model';
+import { Observable, of as observableOf } from 'rxjs';
+import { RequestService } from '../request.service';
+import { RemoteDataBuildService } from '../../cache/builders/remote-data-build.service';
+import { HALEndpointService } from '../../shared/hal-endpoint.service';
+import { ObjectCacheService } from '../../cache/object-cache.service';
+import { IdentifiableDataService } from './identifiable-data.service';
+
+const endpoint = 'https://rest.api/core';
+
+class TestService extends IdentifiableDataService<any> {
+  constructor(
+    protected requestService: RequestService,
+    protected rdbService: RemoteDataBuildService,
+    protected objectCache: ObjectCacheService,
+    protected halService: HALEndpointService,
+  ) {
+    super(undefined, requestService, rdbService, objectCache, halService);
+  }
+
+  public getBrowseEndpoint(options: FindListOptions = {}, linkPath: string = this.linkPath): Observable<string> {
+    return observableOf(endpoint);
+  }
+}
+
+describe('IdentifiableDataService', () => {
+  let service: TestService;
+  let requestService;
+  let halService;
+  let rdbService;
+  let objectCache;
+  let selfLink;
+  let linksToFollow;
+  let testScheduler;
+  let remoteDataMocks;
+
+  function initTestService(): TestService {
+    requestService = getMockRequestService();
+    halService = new HALEndpointServiceStub('url') as any;
+    rdbService = getMockRemoteDataBuildService();
+    objectCache = {
+
+      addPatch: () => {
+        /* empty */
+      },
+      getObjectBySelfLink: () => {
+        /* empty */
+      },
+      getByHref: () => {
+        /* empty */
+      }
+    } as any;
+    selfLink = 'https://rest.api/endpoint/1698f1d3-be98-4c51-9fd8-6bfedcbd59b7';
+    linksToFollow = [
+      followLink('a'),
+      followLink('b')
+    ];
+
+    testScheduler = new TestScheduler((actual, expected) => {
+      // asserting the two objects are equal
+      // e.g. using chai.
+      expect(actual).toEqual(expected);
+    });
+
+    const timeStamp = new Date().getTime();
+    const msToLive = 15 * 60 * 1000;
+    const payload = { foo: 'bar' };
+    const statusCodeSuccess = 200;
+    const statusCodeError = 404;
+    const errorMessage = 'not found';
+    remoteDataMocks = {
+      RequestPending: new RemoteData(undefined, msToLive, timeStamp, RequestEntryState.RequestPending, undefined, undefined, undefined),
+      ResponsePending: new RemoteData(undefined, msToLive, timeStamp, RequestEntryState.ResponsePending, undefined, undefined, undefined),
+      Success: new RemoteData(timeStamp, msToLive, timeStamp, RequestEntryState.Success, undefined, payload, statusCodeSuccess),
+      SuccessStale: new RemoteData(timeStamp, msToLive, timeStamp, RequestEntryState.SuccessStale, undefined, payload, statusCodeSuccess),
+      Error: new RemoteData(timeStamp, msToLive, timeStamp, RequestEntryState.Error, errorMessage, undefined, statusCodeError),
+      ErrorStale: new RemoteData(timeStamp, msToLive, timeStamp, RequestEntryState.ErrorStale, errorMessage, undefined, statusCodeError),
+    };
+
+    return new TestService(
+      requestService,
+      rdbService,
+      objectCache,
+      halService,
+    );
+  }
+
+  beforeEach(() => {
+    service = initTestService();
+  });
+
+  describe('getIDHref', () => {
+    const endpointMock = 'https://dspace7-internal.atmire.com/server/api/core/items';
+    const resourceIdMock = '003c99b4-d4fe-44b0-a945-e12182a7ca89';
+
+    it('should return endpoint', () => {
+      const result = (service as any).getIDHref(endpointMock, resourceIdMock);
+      expect(result).toEqual(endpointMock + '/' + resourceIdMock);
+    });
+
+    it('should include single linksToFollow as embed', () => {
+      const expected = `${endpointMock}/${resourceIdMock}?embed=bundles`;
+      const result = (service as any).getIDHref(endpointMock, resourceIdMock, followLink('bundles'));
+      expect(result).toEqual(expected);
+    });
+
+    it('should include multiple linksToFollow as embed', () => {
+      const expected = `${endpointMock}/${resourceIdMock}?embed=bundles&embed=owningCollection&embed=templateItemOf`;
+      const result = (service as any).getIDHref(endpointMock, resourceIdMock, followLink('bundles'), followLink('owningCollection'), followLink('templateItemOf'));
+      expect(result).toEqual(expected);
+    });
+
+    it('should not include linksToFollow with shouldEmbed = false', () => {
+      const expected = `${endpointMock}/${resourceIdMock}?embed=templateItemOf`;
+      const result = (service as any).getIDHref(
+        endpointMock,
+        resourceIdMock,
+        followLink('bundles', { shouldEmbed: false }),
+        followLink('owningCollection', { shouldEmbed: false }),
+        followLink('templateItemOf')
+      );
+      expect(result).toEqual(expected);
+    });
+
+    it('should include nested linksToFollow 3lvl', () => {
+      const expected = `${endpointMock}/${resourceIdMock}?embed=owningCollection/itemtemplate/relationships`;
+      const result = (service as any).getIDHref(endpointMock, resourceIdMock, followLink('owningCollection', {}, followLink('itemtemplate', {}, followLink('relationships'))));
+      expect(result).toEqual(expected);
+    });
+  });
+});

src/app/core/data/base/identifiable-data.service.ts

@@ -0,0 +1,83 @@
+/**
+ * The contents of this file are subject to the license and copyright
+ * detailed in the LICENSE and NOTICE files at the root of the source
+ * tree and available online at
+ *
+ * http://www.dspace.org/license/
+ */
+import { CacheableObject } from '../../cache/cacheable-object.model';
+import { FollowLinkConfig } from '../../../shared/utils/follow-link-config.model';
+import { Observable } from 'rxjs';
+import { map } from 'rxjs/operators';
+import { RemoteData } from '../remote-data';
+import { BaseDataService } from './base-data.service';
+import { RequestService } from '../request.service';
+import { RemoteDataBuildService } from '../../cache/builders/remote-data-build.service';
+import { ObjectCacheService } from '../../cache/object-cache.service';
+import { HALEndpointService } from '../../shared/hal-endpoint.service';
+
+/**
+ * Shorthand type for the method to construct an ID endpoint.
+ */
+export type ConstructIdEndpoint = (endpoint: string, resourceID: string) => string;
+
+/**
+ * The default method to construct an ID endpoint
+ */
+export const constructIdEndpointDefault = (endpoint, resourceID) => `${endpoint}/${resourceID}`;
+
+/**
+ * A type of data service that deals with objects that have an ID.
+ *
+ * The effective endpoint to use for the ID can be adjusted by providing a different {@link ConstructIdEndpoint} method.
+ * This method is passed as an argument so that it can be set on data service features without having to override them.
+ */
+export class IdentifiableDataService<T extends CacheableObject> extends BaseDataService<T> {
+  constructor(
+    protected linkPath: string,
+    protected requestService: RequestService,
+    protected rdbService: RemoteDataBuildService,
+    protected objectCache: ObjectCacheService,
+    protected halService: HALEndpointService,
+    protected responseMsToLive?: number,
+    protected constructIdEndpoint: ConstructIdEndpoint = constructIdEndpointDefault,
+  ) {
+    super(linkPath, requestService, rdbService, objectCache, halService, responseMsToLive);
+  }
+
+  /**
+   * Returns an observable of {@link RemoteData} of an object, based on its ID, with a list of
+   * {@link FollowLinkConfig}, to automatically resolve {@link HALLink}s of the object
+   * @param id                          ID of object we want to retrieve
+   * @param useCachedVersionIfAvailable If this is true, the request will only be sent if there's
+   *                                    no valid cached version. Defaults to true
+   * @param reRequestOnStale            Whether or not the request should automatically be re-
+   *                                    requested after the response becomes stale
+   * @param linksToFollow               List of {@link FollowLinkConfig} that indicate which
+   *                                    {@link HALLink}s should be automatically resolved
+   */
+  findById(id: string, useCachedVersionIfAvailable = true, reRequestOnStale = true, ...linksToFollow: FollowLinkConfig<T>[]): Observable<RemoteData<T>> {
+    const href$ = this.getIDHrefObs(encodeURIComponent(id), ...linksToFollow);
+    return this.findByHref(href$, useCachedVersionIfAvailable, reRequestOnStale, ...linksToFollow);
+  }
+
+  /**
+   * Create the HREF for a specific object based on its identifier; with possible embed query params based on linksToFollow
+   * @param endpoint The base endpoint for the type of object
+   * @param resourceID The identifier for the object
+   * @param linksToFollow   List of {@link FollowLinkConfig} that indicate which {@link HALLink}s should be automatically resolved
+   */
+  getIDHref(endpoint, resourceID, ...linksToFollow: FollowLinkConfig<T>[]): string {
+    return this.buildHrefFromFindOptions(this.constructIdEndpoint(endpoint, resourceID), {}, [], ...linksToFollow);
+  }
+
+  /**
+   * Create an observable for the HREF of a specific object based on its identifier
+   * @param resourceID The identifier for the object
+   * @param linksToFollow   List of {@link FollowLinkConfig} that indicate which {@link HALLink}s should be automatically resolved
+   */
+  getIDHrefObs(resourceID: string, ...linksToFollow: FollowLinkConfig<T>[]): Observable<string> {
+    return this.getEndpoint().pipe(
+      map((endpoint: string) => this.getIDHref(endpoint, resourceID, ...linksToFollow)));
+  }
+}

src/app/core/data/base/patch-data.spec.ts

@@ -0,0 +1,235 @@
+/**
+ * The contents of this file are subject to the license and copyright
+ * detailed in the LICENSE and NOTICE files at the root of the source
+ * tree and available online at
+ *
+ * http://www.dspace.org/license/
+ */
+/* eslint-disable max-classes-per-file */
+import { RequestService } from '../request.service';
+import { RemoteDataBuildService } from '../../cache/builders/remote-data-build.service';
+import { ObjectCacheService } from '../../cache/object-cache.service';
+import { HALEndpointService } from '../../shared/hal-endpoint.service';
+import { FindListOptions } from '../find-list-options.model';
+import { Observable, of as observableOf } from 'rxjs';
+import { getMockRequestService } from '../../../shared/mocks/request.service.mock';
+import { HALEndpointServiceStub } from '../../../shared/testing/hal-endpoint-service.stub';
+import { getMockRemoteDataBuildService } from '../../../shared/mocks/remote-data-build.service.mock';
+import { followLink } from '../../../shared/utils/follow-link-config.model';
+import { TestScheduler } from 'rxjs/testing';
+import { RemoteData } from '../remote-data';
+import { RequestEntryState } from '../request-entry-state.model';
+import { PatchData, PatchDataImpl } from './patch-data';
+import { ChangeAnalyzer } from '../change-analyzer';
+import { Item } from '../../shared/item.model';
+import { compare, Operation } from 'fast-json-patch';
+import { PatchRequest } from '../request.models';
+import { DSpaceObject } from '../../shared/dspace-object.model';
+import { createSuccessfulRemoteDataObject$ } from '../../../shared/remote-data.utils';
+import { constructIdEndpointDefault } from './identifiable-data.service';
+import { RestRequestMethod } from '../rest-request-method';
+
+/**
+ * Tests whether calls to `PatchData` methods are correctly patched through in a concrete data service that implements it
+ */
+export function testPatchDataImplementation(serviceFactory: () => PatchData<any>) {
+  let service;
+
+  describe('PatchData implementation', () => {
+    const OBJ = Object.assign(new DSpaceObject(), {
+      uuid: '08eec68f-45e4-47a3-80c5-f0beb5627079',
+    });
+    const OPERATIONS = [
+      { op: 'replace', path: '/0/value', value: 'test' },
+      { op: 'add', path: '/2/value', value: 'test2' },
+    ] as Operation[];
+    const METHOD = RestRequestMethod.POST;
+
+    beforeAll(() => {
+      service = serviceFactory();
+      (service as any).patchData = jasmine.createSpyObj('patchData', {
+        patch: 'TEST patch',
+        update: 'TEST update',
+        commitUpdates: undefined,
+        createPatchFromCache: 'TEST createPatchFromCache',
+      });
+    });
+
+    it('should handle calls to patch', () => {
+      const out: any = service.patch(OBJ, OPERATIONS);
+
+      expect((service as any).patchData.patch).toHaveBeenCalledWith(OBJ, OPERATIONS);
+      expect(out).toBe('TEST patch');
+    });
+
+    it('should handle calls to update', () => {
+      const out: any = service.update(OBJ);
+
+      expect((service as any).patchData.update).toHaveBeenCalledWith(OBJ);
+      expect(out).toBe('TEST update');
+    });
+
+    it('should handle calls to commitUpdates', () => {
+      service.commitUpdates(METHOD);
+      expect((service as any).patchData.commitUpdates).toHaveBeenCalledWith(METHOD);
+    });
+
+    it('should handle calls to createPatchFromCache', () => {
+      const out: any = service.createPatchFromCache(OBJ);
+
+      expect((service as any).patchData.createPatchFromCache).toHaveBeenCalledWith(OBJ);
+      expect(out).toBe('TEST createPatchFromCache');
+    });
+  });
+}
+
+const endpoint = 'https://rest.api/core';
+
+class TestService extends PatchDataImpl<any> {
+  constructor(
+    protected requestService: RequestService,
+    protected rdbService: RemoteDataBuildService,
+    protected objectCache: ObjectCacheService,
+    protected halService: HALEndpointService,
+    protected comparator: ChangeAnalyzer<Item>,
+  ) {
+    super(undefined, requestService, rdbService, objectCache, halService, comparator, undefined, constructIdEndpointDefault);
+  }
+
+  public getBrowseEndpoint(options: FindListOptions = {}, linkPath: string = this.linkPath): Observable<string> {
+    return observableOf(endpoint);
+  }
+}
+
+class DummyChangeAnalyzer implements ChangeAnalyzer<Item> {
+  diff(object1: Item, object2: Item): Operation[] {
+    return compare((object1 as any).metadata, (object2 as any).metadata);
+  }
+}
+
+describe('PatchDataImpl', () => {
+  let service: TestService;
+  let requestService;
+  let halService;
+  let rdbService;
+  let comparator;
+  let objectCache;
+  let selfLink;
+  let linksToFollow;
+  let testScheduler;
+  let remoteDataMocks;
+
+  function initTestService(): TestService {
+    requestService = getMockRequestService();
+    halService = new HALEndpointServiceStub('url') as any;
+    rdbService = getMockRemoteDataBuildService();
+    comparator = new DummyChangeAnalyzer() as any;
+    objectCache = {
+
+      addPatch: () => {
+        /* empty */
+      },
+      getObjectBySelfLink: () => {
+        /* empty */
+      },
+      getByHref: () => {
+        /* empty */
+      },
+    } as any;
+    selfLink = 'https://rest.api/endpoint/1698f1d3-be98-4c51-9fd8-6bfedcbd59b7';
+    linksToFollow = [
+      followLink('a'),
+      followLink('b'),
+    ];
+
+    testScheduler = new TestScheduler((actual, expected) => {
+      // asserting the two objects are equal
+      // e.g. using chai.
+      expect(actual).toEqual(expected);
+    });
+
+    const timeStamp = new Date().getTime();
+    const msToLive = 15 * 60 * 1000;
+    const payload = { foo: 'bar' };
+    const statusCodeSuccess = 200;
+    const statusCodeError = 404;
+    const errorMessage = 'not found';
+    remoteDataMocks = {
+      RequestPending: new RemoteData(undefined, msToLive, timeStamp, RequestEntryState.RequestPending, undefined, undefined, undefined),
+      ResponsePending: new RemoteData(undefined, msToLive, timeStamp, RequestEntryState.ResponsePending, undefined, undefined, undefined),
+      Success: new RemoteData(timeStamp, msToLive, timeStamp, RequestEntryState.Success, undefined, payload, statusCodeSuccess),
+      SuccessStale: new RemoteData(timeStamp, msToLive, timeStamp, RequestEntryState.SuccessStale, undefined, payload, statusCodeSuccess),
+      Error: new RemoteData(timeStamp, msToLive, timeStamp, RequestEntryState.Error, errorMessage, undefined, statusCodeError),
+      ErrorStale: new RemoteData(timeStamp, msToLive, timeStamp, RequestEntryState.ErrorStale, errorMessage, undefined, statusCodeError),
+    };
+
+    return new TestService(
+      requestService,
+      rdbService,
+      objectCache,
+      halService,
+      comparator,
+    );
+  }
+
+  beforeEach(() => {
+    service = initTestService();
+  });
+
+  describe('patch', () => {
+    const dso = {
+      uuid: 'dso-uuid'
+    };
+    const operations = [
+      Object.assign({
+        op: 'move',
+        from: '/1',
+        path: '/5'
+      }) as Operation
+    ];
+
+    beforeEach((done) => {
+      service.patch(dso, operations).subscribe(() => {
+        done();
+      });
+    });
+
+    it('should send a PatchRequest', () => {
+      expect(requestService.send).toHaveBeenCalledWith(jasmine.any(PatchRequest));
+    });
+  });
+
+  describe('update', () => {
+    let operations;
+    let dso;
+    let dso2;
+    const name1 = 'random string';
+    const name2 = 'another random string';
+    beforeEach(() => {
+      operations = [{ op: 'replace', path: '/0/value', value: name2 } as Operation];
+
+      dso = Object.assign(new DSpaceObject(), {
+        _links: { self: { href: selfLink } },
+        metadata: [{ key: 'dc.title', value: name1 }]
+      });
+
+      dso2 = Object.assign(new DSpaceObject(), {
+        _links: { self: { href: selfLink } },
+        metadata: [{ key: 'dc.title', value: name2 }]
+      });
+
+      spyOn(service, 'findByHref').and.returnValue(createSuccessfulRemoteDataObject$(dso));
+      spyOn(objectCache, 'addPatch');
+    });
+
+    it('should call addPatch on the object cache with the right parameters when there are differences', () => {
+      service.update(dso2).subscribe();
+      expect(objectCache.addPatch).toHaveBeenCalledWith(selfLink, operations);
+    });
+
+    it('should not call addPatch on the object cache with the right parameters when there are no differences', () => {
+      service.update(dso).subscribe();
+      expect(objectCache.addPatch).not.toHaveBeenCalled();
+    });
+  });
+});

src/app/core/data/base/patch-data.ts

@@ -0,0 +1,143 @@
+/**
+ * The contents of this file are subject to the license and copyright
+ * detailed in the LICENSE and NOTICE files at the root of the source
+ * tree and available online at
+ *
+ * http://www.dspace.org/license/
+ */
+import { CacheableObject } from '../../cache/cacheable-object.model';
+import { Operation } from 'fast-json-patch';
+import { Observable } from 'rxjs';
+import { RemoteData } from '../remote-data';
+import { find, map, mergeMap } from 'rxjs/operators';
+import { hasNoValue, hasValue, isNotEmpty } from '../../../shared/empty.util';
+import { PatchRequest } from '../request.models';
+import { getFirstSucceededRemoteData, getRemoteDataPayload } from '../../shared/operators';
+import { ChangeAnalyzer } from '../change-analyzer';
+import { RequestService } from '../request.service';
+import { RemoteDataBuildService } from '../../cache/builders/remote-data-build.service';
+import { HALEndpointService } from '../../shared/hal-endpoint.service';
+import { ObjectCacheService } from '../../cache/object-cache.service';
+import { RestRequestMethod } from '../rest-request-method';
+import { ConstructIdEndpoint, IdentifiableDataService } from './identifiable-data.service';
+
+
+/**
+ * Interface for a data service that can patch and update objects.
+ */
+export interface PatchData<T extends CacheableObject> {
+  /**
+   * Send a patch request for a specified object
+   * @param {T} object The object to send a patch request for
+   * @param {Operation[]} operations The patch operations to be performed
+   */
+  patch(object: T, operations: Operation[]): Observable<RemoteData<T>>;
+
+  /**
+   * Add a new patch to the object cache
+   * The patch is derived from the differences between the given object and its version in the object cache
+   * @param {DSpaceObject} object The given object
+   */
+  update(object: T): Observable<RemoteData<T>>;
+
+  /**
+   * Commit current object changes to the server
+   * @param method The RestRequestMethod for which de server sync buffer should be committed
+   */
+  commitUpdates(method?: RestRequestMethod): void;
+
+  /**
+   * Return a list of operations representing the difference between an object and its latest value in the cache.
+   * @param object  the object to resolve to a list of patch operations
+   */
+  createPatchFromCache(object: T): Observable<Operation[]>;
+}
+
+/**
+ * A DataService feature to patch and update objects.
+ *
+ * Concrete data services can use this feature by implementing {@link PatchData}
+ * and delegating its method to an inner instance of this class.
+ *
+ * Note that this feature requires the object in question to have an ID.
+ * Make sure to use the same {@link ConstructIdEndpoint} as in the parent data service.
+ */
+export class PatchDataImpl<T extends CacheableObject> extends IdentifiableDataService<T> implements PatchData<T> {
+  constructor(
+    protected linkPath: string,
+    protected requestService: RequestService,
+    protected rdbService: RemoteDataBuildService,
+    protected objectCache: ObjectCacheService,
+    protected halService: HALEndpointService,
+    protected comparator: ChangeAnalyzer<T>,
+    protected responseMsToLive: number,
+    protected constructIdEndpoint: ConstructIdEndpoint,
+  ) {
+    super(linkPath, requestService, rdbService, objectCache, halService, responseMsToLive, constructIdEndpoint);
+    if (hasNoValue(constructIdEndpoint)) {
+      throw new Error(`PatchDataImpl initialized without a constructIdEndpoint method (linkPath: ${linkPath})`);
+    }
+  }
+
+  /**
+   * Send a patch request for a specified object
+   * @param {T} object The object to send a patch request for
+   * @param {Operation[]} operations The patch operations to be performed
+   */
+  patch(object: T, operations: Operation[]): Observable<RemoteData<T>> {
+    const requestId = this.requestService.generateRequestId();
+
+    const hrefObs = this.halService.getEndpoint(this.linkPath).pipe(
+      map((endpoint: string) => this.getIDHref(endpoint, object.uuid)),
+    );
+
+    hrefObs.pipe(
+      find((href: string) => hasValue(href)),
+    ).subscribe((href: string) => {
+      const request = new PatchRequest(requestId, href, operations);
+      if (hasValue(this.responseMsToLive)) {
+        request.responseMsToLive = this.responseMsToLive;
+      }
+      this.requestService.send(request);
+    });
+
+    return this.rdbService.buildFromRequestUUID(requestId);
+  }
+
+  /**
+   * Add a new patch to the object cache
+   * The patch is derived from the differences between the given object and its version in the object cache
+   * @param {DSpaceObject} object The given object
+   */
+  update(object: T): Observable<RemoteData<T>> {
+    return this.createPatchFromCache(object).pipe(
+      mergeMap((operations: Operation[]) => {
+        if (isNotEmpty(operations)) {
+          this.objectCache.addPatch(object._links.self.href, operations);
+        }
+        return this.findByHref(object._links.self.href, true, true);
+      }),
+    );
+  }
+
+  /**
+   * Commit current object changes to the server
+   * @param method The RestRequestMethod for which de server sync buffer should be committed
+   */
+  commitUpdates(method?: RestRequestMethod): void {
+    this.requestService.commit(method);
+  }
+
+  /**
+   * Return a list of operations representing the difference between an object and its latest value in the cache.
+   * @param object  the object to resolve to a list of patch operations
+   */
+  createPatchFromCache(object: T): Observable<Operation[]> {
+    const oldVersion$ = this.findByHref(object._links.self.href, true, false);
+    return oldVersion$.pipe(
+      getFirstSucceededRemoteData(),
+      getRemoteDataPayload(),
+      map((oldVersion: T) => this.comparator.diff(oldVersion, object)),
+    );
+  }
+}

src/app/core/data/base/put-data.spec.ts

@@ -0,0 +1,176 @@
+/**
+ * The contents of this file are subject to the license and copyright
+ * detailed in the LICENSE and NOTICE files at the root of the source
+ * tree and available online at
+ *
+ * http://www.dspace.org/license/
+ */
+
+import { RequestService } from '../request.service';
+import { RemoteDataBuildService } from '../../cache/builders/remote-data-build.service';
+import { ObjectCacheService } from '../../cache/object-cache.service';
+import { HALEndpointService } from '../../shared/hal-endpoint.service';
+import { FindListOptions } from '../find-list-options.model';
+import { Observable, of as observableOf } from 'rxjs';
+import { getMockRequestService } from '../../../shared/mocks/request.service.mock';
+import { HALEndpointServiceStub } from '../../../shared/testing/hal-endpoint-service.stub';
+import { getMockRemoteDataBuildService } from '../../../shared/mocks/remote-data-build.service.mock';
+import { RemoteData } from '../remote-data';
+import { RequestEntryState } from '../request-entry-state.model';
+import { PutData, PutDataImpl } from './put-data';
+import { RestRequestMethod } from '../rest-request-method';
+import { DSpaceObject } from '../../shared/dspace-object.model';
+
+/**
+ * Tests whether calls to `PutData` methods are correctly patched through in a concrete data service that implements it
+ */
+export function testPutDataImplementation(serviceFactory: () => PutData<any>) {
+  let service;
+
+  describe('PutData implementation', () => {
+    const OBJ = Object.assign(new DSpaceObject(), {
+      uuid: '08eec68f-45e4-47a3-80c5-f0beb5627079',
+    });
+
+    beforeAll(() => {
+      service = serviceFactory();
+      (service as any).putData = jasmine.createSpyObj('putData', {
+        put: 'TEST put',
+      });
+    });
+
+    it('should handle calls to put', () => {
+      const out: any = service.put(OBJ);
+
+      expect((service as any).putData.put).toHaveBeenCalledWith(OBJ);
+      expect(out).toBe('TEST put');
+    });
+  });
+}
+
+
+const endpoint = 'https://rest.api/core';
+
+class TestService extends PutDataImpl<any> {
+  constructor(
+    protected requestService: RequestService,
+    protected rdbService: RemoteDataBuildService,
+    protected objectCache: ObjectCacheService,
+    protected halService: HALEndpointService,
+  ) {
+    super(undefined, requestService, rdbService, objectCache, halService, undefined);
+  }
+
+  public getBrowseEndpoint(options: FindListOptions = {}, linkPath: string = this.linkPath): Observable<string> {
+    return observableOf(endpoint);
+  }
+}
+
+describe('PutDataImpl', () => {
+  let service: TestService;
+  let requestService;
+  let halService;
+  let rdbService;
+  let objectCache;
+  let selfLink;
+  let remoteDataMocks;
+
+  let obj;
+  let buildFromRequestUUIDSpy: jasmine.Spy;
+
+  function initTestService(): TestService {
+    requestService = getMockRequestService();
+    halService = new HALEndpointServiceStub('url') as any;
+    rdbService = getMockRemoteDataBuildService();
+    objectCache = {
+
+      addPatch: () => {
+        /* empty */
+      },
+      getObjectBySelfLink: () => {
+        /* empty */
+      },
+      getByHref: () => {
+        /* empty */
+      },
+    } as any;
+    selfLink = 'https://rest.api/endpoint/1698f1d3-be98-4c51-9fd8-6bfedcbd59b7';
+
+    const timeStamp = new Date().getTime();
+    const msToLive = 15 * 60 * 1000;
+    const payload = { foo: 'bar' };
+    const statusCodeSuccess = 200;
+    const statusCodeError = 404;
+    const errorMessage = 'not found';
+    remoteDataMocks = {
+      RequestPending: new RemoteData(undefined, msToLive, timeStamp, RequestEntryState.RequestPending, undefined, undefined, undefined),
+      ResponsePending: new RemoteData(undefined, msToLive, timeStamp, RequestEntryState.ResponsePending, undefined, undefined, undefined),
+      Success: new RemoteData(timeStamp, msToLive, timeStamp, RequestEntryState.Success, undefined, payload, statusCodeSuccess),
+      SuccessStale: new RemoteData(timeStamp, msToLive, timeStamp, RequestEntryState.SuccessStale, undefined, payload, statusCodeSuccess),
+      Error: new RemoteData(timeStamp, msToLive, timeStamp, RequestEntryState.Error, errorMessage, undefined, statusCodeError),
+      ErrorStale: new RemoteData(timeStamp, msToLive, timeStamp, RequestEntryState.ErrorStale, errorMessage, undefined, statusCodeError),
+    };
+
+    return new TestService(
+      requestService,
+      rdbService,
+      objectCache,
+      halService,
+    );
+  }
+
+  beforeEach(() => {
+    service = initTestService();
+
+    obj = Object.assign(new DSpaceObject(), {
+      uuid: '1698f1d3-be98-4c51-9fd8-6bfedcbd59b7',
+      metadata: {           // recognized properties will be serialized
+        ['dc.title']: [
+          { language: 'en', value: 'some object' },
+        ]
+      },
+      data: [ 1, 2, 3, 4 ], // unrecognized properties won't be serialized
+      _links: { self: { href: selfLink } },
+    });
+
+
+    buildFromRequestUUIDSpy = spyOn(rdbService, 'buildFromRequestUUID').and.returnValue(observableOf(remoteDataMocks.Success));
+  });
+
+  describe('put', () => {
+    it('should send a PUT request with the serialized object', (done) => {
+      service.put(obj).subscribe(() => {
+        expect(requestService.send).toHaveBeenCalledWith(jasmine.objectContaining({
+          method: RestRequestMethod.PUT,
+          body: {  // _links are not serialized
+            uuid: obj.uuid,
+            metadata: obj.metadata
+          },
+        }));
+        done();
+      });
+    });
+
+    it('should send the PUT request to the object\'s self link', (done) => {
+      service.put(obj).subscribe(() => {
+        expect(requestService.send).toHaveBeenCalledWith(jasmine.objectContaining({
+          method: RestRequestMethod.PUT,
+          href: selfLink,
+        }));
+        done();
+      });
+    });
+
+    it('should return the remote data for the sent request', (done) => {
+      service.put(obj).subscribe(out => {
+        expect(requestService.send).toHaveBeenCalledWith(jasmine.objectContaining({
+          method: RestRequestMethod.PUT,
+          uuid: requestService.generateRequestId(),
+        }));
+        expect(buildFromRequestUUIDSpy).toHaveBeenCalledWith(requestService.generateRequestId());
+        expect(out).toEqual(remoteDataMocks.Success);
+        done();
+      });
+    });
+  });
+});

src/app/core/data/base/put-data.ts

@@ -0,0 +1,69 @@
+/**
+ * The contents of this file are subject to the license and copyright
+ * detailed in the LICENSE and NOTICE files at the root of the source
+ * tree and available online at
+ *
+ * http://www.dspace.org/license/
+ */
+import { CacheableObject } from '../../cache/cacheable-object.model';
+import { BaseDataService } from './base-data.service';
+import { Observable } from 'rxjs';
+import { RemoteData } from '../remote-data';
+import { DSpaceSerializer } from '../../dspace-rest/dspace.serializer';
+import { GenericConstructor } from '../../shared/generic-constructor';
+import { PutRequest } from '../request.models';
+import { hasValue } from '../../../shared/empty.util';
+import { RequestService } from '../request.service';
+import { RemoteDataBuildService } from '../../cache/builders/remote-data-build.service';
+import { ObjectCacheService } from '../../cache/object-cache.service';
+import { HALEndpointService } from '../../shared/hal-endpoint.service';
+
+/**
+ * Interface for a data service that can send PUT requests.
+ */
+export interface PutData<T extends CacheableObject> {
+  /**
+   * Send a PUT request for the specified object
+   *
+   * @param object The object to send a put request for.
+   */
+  put(object: T): Observable<RemoteData<T>>;
+}
+
+/**
+ * A DataService feature to send PUT requests.
+ *
+ * Concrete data services can use this feature by implementing {@link PutData}
+ * and delegating its method to an inner instance of this class.
+ */
+export class PutDataImpl<T extends CacheableObject> extends BaseDataService<T> implements PutData<T> {
+  constructor(
+    protected linkPath: string,
+    protected requestService: RequestService,
+    protected rdbService: RemoteDataBuildService,
+    protected objectCache: ObjectCacheService,
+    protected halService: HALEndpointService,
+    protected responseMsToLive: number,
+  ) {
+    super(linkPath, requestService, rdbService, objectCache, halService, responseMsToLive);
+  }
+
+  /**
+   * Send a PUT request for the specified object
+   *
+   * @param object The object to send a put request for.
+   */
+  put(object: T): Observable<RemoteData<T>> {
+    const requestId = this.requestService.generateRequestId();
+    const serializedObject = new DSpaceSerializer(object.constructor as GenericConstructor<{}>).serialize(object);
+    const request = new PutRequest(requestId, object._links.self.href, serializedObject);
+
+    if (hasValue(this.responseMsToLive)) {
+      request.responseMsToLive = this.responseMsToLive;
+    }
+
+    this.requestService.send(request);
+
+    return this.rdbService.buildFromRequestUUID(requestId);
+  }
+}

src/app/core/data/base/search-data.spec.ts

@@ -0,0 +1,141 @@
+/**
+ * The contents of this file are subject to the license and copyright
+ * detailed in the LICENSE and NOTICE files at the root of the source
+ * tree and available online at
+ *
+ * http://www.dspace.org/license/
+ */
+import { constructSearchEndpointDefault, SearchData, SearchDataImpl } from './search-data';
+import { FindListOptions } from '../find-list-options.model';
+import { followLink } from '../../../shared/utils/follow-link-config.model';
+import { of as observableOf } from 'rxjs';
+import { getMockRequestService } from '../../../shared/mocks/request.service.mock';
+import { getMockRemoteDataBuildService } from '../../../shared/mocks/remote-data-build.service.mock';
+
+/**
+ * Tests whether calls to `SearchData` methods are correctly patched through in a concrete data service that implements it
+ */
+export function testSearchDataImplementation(serviceFactory: () => SearchData<any>) {
+  let service;
+
+  describe('SearchData implementation', () => {
+    const OPTIONS = Object.assign(new FindListOptions(), { elementsPerPage: 10, currentPage: 3 });
+    const FOLLOWLINKS = [
+      followLink('test'),
+      followLink('something'),
+    ];
+
+    beforeAll(() => {
+      service = serviceFactory();
+      (service as any).searchData = jasmine.createSpyObj('searchData', {
+        searchBy: 'TEST searchBy',
+      });
+    });
+
+    it('should handle calls to searchBy', () => {
+      const out: any = service.searchBy('searchMethod', OPTIONS, false, true, ...FOLLOWLINKS);
+
+      expect((service as any).searchData.searchBy).toHaveBeenCalledWith('searchMethod', OPTIONS, false, true, ...FOLLOWLINKS);
+      expect(out).toBe('TEST searchBy');
+    });
+  });
+}
+
+const endpoint = 'https://rest.api/core';
+
+describe('SearchDataImpl', () => {
+  let service: SearchDataImpl<any>;
+  let requestService;
+  let halService;
+  let rdbService;
+  let linksToFollow;
+
+  let constructSearchEndpointSpy;
+  let options;
+
+  function initTestService(): SearchDataImpl<any> {
+    requestService = getMockRequestService();
+    halService = jasmine.createSpyObj('halService', {
+      getEndpoint: observableOf(endpoint),
+    });
+    rdbService = getMockRemoteDataBuildService();
+    linksToFollow = [
+      followLink('a'),
+      followLink('b'),
+    ];
+
+    constructSearchEndpointSpy = jasmine.createSpy('constructSearchEndpointSpy').and.callFake(constructSearchEndpointDefault);
+
+    options = Object.assign(new FindListOptions(), {
+      elementsPerPage: 5,
+      currentPage: 3,
+    });
+
+    return new SearchDataImpl(
+      'test',
+      requestService,
+      rdbService,
+      undefined,
+      halService,
+      undefined,
+      constructSearchEndpointSpy,
+    );
+  }
+
+  beforeEach(() => {
+    service = initTestService();
+  });
+
+  describe('getSearchEndpoint', () => {
+    it('should return the search endpoint for the given method', (done) => {
+      (service as any).getSearchEndpoint('testMethod').subscribe(searchEndpoint => {
+        expect(halService.getEndpoint).toHaveBeenCalledWith('test');
+        expect(searchEndpoint).toBe('https://rest.api/core/search/testMethod');
+        done();
+      });
+    });
+
+    it('should use constructSearchEndpoint to construct the search endpoint', (done) => {
+      (service as any).getSearchEndpoint('testMethod').subscribe(() => {
+        expect(constructSearchEndpointSpy).toHaveBeenCalledWith('https://rest.api/core', 'testMethod');
+        done();
+      });
+    });
+  });
+
+  describe('getSearchByHref', () => {
+    beforeEach(() => {
+      spyOn(service as any, 'getSearchEndpoint').and.callThrough();
+      spyOn(service, 'buildHrefFromFindOptions').and.callThrough();
+    });
+
+    it('should return the search endpoint with additional query parameters', (done) => {
+      service.getSearchByHref('testMethod', options, ...linksToFollow).subscribe(href => {
+        expect((service as any).getSearchEndpoint).toHaveBeenCalledWith('testMethod');
+        expect(service.buildHrefFromFindOptions).toHaveBeenCalledWith(
+          'https://rest.api/core/search/testMethod',
+          options,
+          [],
+          ...linksToFollow,
+        );
+
+        expect(href).toBe('https://rest.api/core/search/testMethod?page=2&size=5&embed=a&embed=b');
+
+        done();
+      });
+    });
+  });
+
+  describe('searchBy', () => {
+    it('should patch getSearchEndpoint into findListByHref and return the result', () => {
+      spyOn(service, 'getSearchByHref').and.returnValue('endpoint' as any);
+      spyOn(service, 'findListByHref').and.returnValue('resulting remote data' as any);
+
+      const out: any = service.searchBy('testMethod', options, false, true, ...linksToFollow);
+
+      expect(service.getSearchByHref).toHaveBeenCalledWith('testMethod', options, ...linksToFollow);
+      expect(service.findListByHref).toHaveBeenCalledWith('endpoint', undefined, false, true, ...linksToFollow);
+      expect(out).toBe('resulting remote data');
+    });
+  });
+});

src/app/core/data/base/search-data.ts

@@ -0,0 +1,134 @@
+/**
+ * The contents of this file are subject to the license and copyright
+ * detailed in the LICENSE and NOTICE files at the root of the source
+ * tree and available online at
+ *
+ * http://www.dspace.org/license/
+ */
+import { CacheableObject } from '../../cache/cacheable-object.model';
+import { BaseDataService } from './base-data.service';
+import { Observable } from 'rxjs';
+import { filter, map } from 'rxjs/operators';
+import { hasNoValue, isNotEmpty } from '../../../shared/empty.util';
+import { FindListOptions } from '../find-list-options.model';
+import { FollowLinkConfig } from '../../../shared/utils/follow-link-config.model';
+import { RemoteData } from '../remote-data';
+import { PaginatedList } from '../paginated-list.model';
+import { RequestService } from '../request.service';
+import { RemoteDataBuildService } from '../../cache/builders/remote-data-build.service';
+import { ObjectCacheService } from '../../cache/object-cache.service';
+import { HALEndpointService } from '../../shared/hal-endpoint.service';
+
+/**
+ * Shorthand type for method to construct a search endpoint
+ */
+export type ConstructSearchEndpoint = (href: string, searchMethod: string) => string;
+
+/**
+ * Default method to construct a search endpoint
+ */
+export const constructSearchEndpointDefault = (href: string, searchMethod: string): string => `${href}/search/${searchMethod}`;
+
+/**
+ * Interface for a data service that can search for objects.
+ */
+export interface SearchData<T extends CacheableObject> {
+  /**
+   * Make a new FindListRequest with given search method
+   *
+   * @param searchMethod                The search method for the object
+   * @param options                     The [[FindListOptions]] object
+   * @param useCachedVersionIfAvailable If this is true, the request will only be sent if there's
+   *                                    no valid cached version. Defaults to true
+   * @param reRequestOnStale            Whether or not the request should automatically be re-
+   *                                    requested after the response becomes stale
+   * @param linksToFollow               List of {@link FollowLinkConfig} that indicate which
+   *                                    {@link HALLink}s should be automatically resolved
+   * @return {Observable<RemoteData<PaginatedList<T>>}
+   *    Return an observable that emits response from the server
+   */
+  searchBy(searchMethod: string, options?: FindListOptions, useCachedVersionIfAvailable?: boolean, reRequestOnStale?: boolean, ...linksToFollow: FollowLinkConfig<T>[]): Observable<RemoteData<PaginatedList<T>>>;
+}
+
+/**
+ * A DataService feature to search for objects.
+ *
+ * Concrete data services can use this feature by implementing {@link SearchData}
+ * and delegating its method to an inner instance of this class.
+ */
+export class SearchDataImpl<T extends CacheableObject> extends BaseDataService<T> implements SearchData<T> {
+  /**
+   * @param linkPath
+   * @param requestService
+   * @param rdbService
+   * @param objectCache
+   * @param halService
+   * @param responseMsToLive
+   * @param constructSearchEndpoint      an optional method to construct the search endpoint, passed as an argument so it can be
+   *                            modified without extending this class. Defaults to `${href}/search/${searchMethod}`
+   */
+  constructor(
+    protected linkPath: string,
+    protected requestService: RequestService,
+    protected rdbService: RemoteDataBuildService,
+    protected objectCache: ObjectCacheService,
+    protected halService: HALEndpointService,
+    protected responseMsToLive: number,
+    private constructSearchEndpoint: ConstructSearchEndpoint = constructSearchEndpointDefault,
+  ) {
+    super(linkPath, requestService, rdbService, objectCache, halService, responseMsToLive);
+    if (hasNoValue(constructSearchEndpoint)) {
+      throw new Error(`SearchDataImpl initialized without a constructSearchEndpoint method (linkPath: ${linkPath})`);
+    }
+  }
+
+  /**
+   * Make a new FindListRequest with given search method
+   *
+   * @param searchMethod                The search method for the object
+   * @param options                     The [[FindListOptions]] object
+   * @param useCachedVersionIfAvailable If this is true, the request will only be sent if there's
+   *                                    no valid cached version. Defaults to true
+   * @param reRequestOnStale            Whether or not the request should automatically be re-
+   *                                    requested after the response becomes stale
+   * @param linksToFollow               List of {@link FollowLinkConfig} that indicate which
+   *                                    {@link HALLink}s should be automatically resolved
+   * @return {Observable<RemoteData<PaginatedList<T>>}
+   *    Return an observable that emits response from the server
+   */
+  searchBy(searchMethod: string, options: FindListOptions = {}, useCachedVersionIfAvailable = true, reRequestOnStale = true, ...linksToFollow: FollowLinkConfig<T>[]): Observable<RemoteData<PaginatedList<T>>> {
+    const hrefObs = this.getSearchByHref(searchMethod, options, ...linksToFollow);
+
+    return this.findListByHref(hrefObs, undefined, useCachedVersionIfAvailable, reRequestOnStale, ...linksToFollow);
+  }
+
+  /**
+   * Create the HREF for a specific object's search method with given options object
+   *
+   * @param searchMethod The search method for the object
+   * @param options The [[FindListOptions]] object
+   * @return {Observable<string>}
+   *    Return an observable that emits created HREF
+   * @param linksToFollow   List of {@link FollowLinkConfig} that indicate which {@link HALLink}s should be automatically resolved
+   */
+  getSearchByHref(searchMethod: string, options: FindListOptions = {}, ...linksToFollow: FollowLinkConfig<T>[]): Observable<string> {
+    let result$: Observable<string>;
+    const args = [];
+
+    result$ = this.getSearchEndpoint(searchMethod);
+
+    return result$.pipe(map((result: string) => this.buildHrefFromFindOptions(result, options, args, ...linksToFollow)));
+  }
+
+  /**
+   * Return object search endpoint by given search method
+   *
+   * @param searchMethod The search method for the object
+   */
+  private getSearchEndpoint(searchMethod: string): Observable<string> {
+    return this.halService.getEndpoint(this.linkPath).pipe(
+      filter((href: string) => isNotEmpty(href)),
+      map(href => this.constructSearchEndpoint(href, searchMethod)),
+    );
+  }
+}

src/app/core/data/bitstream-data.service.spec.ts

@@ -12,6 +12,9 @@ import { getMockRequestService } from '../../shared/mocks/request.service.mock';
 import { HALEndpointServiceStub } from '../../shared/testing/hal-endpoint-service.stub';
 import { RemoteDataBuildService } from '../cache/builders/remote-data-build.service';
 import { getMockRemoteDataBuildService } from '../../shared/mocks/remote-data-build.service.mock';
+import { testSearchDataImplementation } from './base/search-data.spec';
+import { testPatchDataImplementation } from './base/patch-data.spec';
+import { testDeleteDataImplementation } from './base/delete-data.spec';
 
 describe('BitstreamDataService', () => {
   let service: BitstreamDataService;
@@ -47,7 +50,14 @@ describe('BitstreamDataService', () => {
     });
     rdbService = getMockRemoteDataBuildService();
 
-    service = new BitstreamDataService(requestService, rdbService, null, objectCache, halService, null, null, null, null, bitstreamFormatService);
+    service = new BitstreamDataService(requestService, rdbService, objectCache, halService, null, bitstreamFormatService, null, null);
+  });
+
+  describe('composition', () => {
+    const initService = () => new BitstreamDataService(null, null, null, null, null, null, null, null);
+    testSearchDataImplementation(initService);
+    testPatchDataImplementation(initService);
+    testDeleteDataImplementation(initService);
   });
 
   describe('when updating the bitstream\'s format', () => {

src/app/core/data/bitstream-data.service.ts

@@ -1,12 +1,9 @@
-import { HttpClient, HttpHeaders } from '@angular/common/http';
+import { HttpHeaders } from '@angular/common/http';
 import { Injectable } from '@angular/core';
-import { Store } from '@ngrx/store';
 import { combineLatest as observableCombineLatest, Observable } from 'rxjs';
 import { map, switchMap, take } from 'rxjs/operators';
 import { hasValue } from '../../shared/empty.util';
-import { NotificationsService } from '../../shared/notifications/notifications.service';
 import { FollowLinkConfig } from '../../shared/utils/follow-link-config.model';
-import { dataService } from '../cache/builders/build-decorators';
 import { RemoteDataBuildService } from '../cache/builders/remote-data-build.service';
 import { ObjectCacheService } from '../cache/object-cache.service';
 import { Bitstream } from '../shared/bitstream.model';
@@ -15,8 +12,6 @@ import { Bundle } from '../shared/bundle.model';
 import { HALEndpointService } from '../shared/hal-endpoint.service';
 import { Item } from '../shared/item.model';
 import { BundleDataService } from './bundle-data.service';
-import { DataService } from './data.service';
-import { DSOChangeAnalyzer } from './dso-change-analyzer.service';
 import { buildPaginatedList, PaginatedList } from './paginated-list.model';
 import { RemoteData } from './remote-data';
 import { PutRequest } from './request.models';
@@ -28,36 +23,45 @@ import { createSuccessfulRemoteDataObject$ } from '../../shared/remote-data.util
 import { PageInfo } from '../shared/page-info.model';
 import { RequestParam } from '../cache/models/request-param.model';
 import { sendRequest } from '../shared/request.operators';
-import { CoreState } from '../core-state.model';
 import { FindListOptions } from './find-list-options.model';
+import { SearchData, SearchDataImpl } from './base/search-data';
+import { PatchData, PatchDataImpl } from './base/patch-data';
+import { DSOChangeAnalyzer } from './dso-change-analyzer.service';
+import { RestRequestMethod } from './rest-request-method';
+import { DeleteData, DeleteDataImpl } from './base/delete-data';
+import { NotificationsService } from '../../shared/notifications/notifications.service';
+import { NoContent } from '../shared/NoContent.model';
+import { IdentifiableDataService } from './base/identifiable-data.service';
+import { dataService } from './base/data-service.decorator';
+import { Operation } from 'fast-json-patch';
 
 /**
  * A service to retrieve {@link Bitstream}s from the REST API
  */
 @Injectable({
-  providedIn: 'root'
+  providedIn: 'root',
 })
 @dataService(BITSTREAM)
-export class BitstreamDataService extends DataService<Bitstream> {
+export class BitstreamDataService extends IdentifiableDataService<Bitstream> implements SearchData<Bitstream>, PatchData<Bitstream>, DeleteData<Bitstream> {
-
+  private searchData: SearchDataImpl<Bitstream>;
-  /**
+  private patchData: PatchDataImpl<Bitstream>;
-   * The HAL path to the bitstream endpoint
+  private deleteData: DeleteDataImpl<Bitstream>;
-   */
-  protected linkPath = 'bitstreams';
 
   constructor(
     protected requestService: RequestService,
     protected rdbService: RemoteDataBuildService,
-    protected store: Store<CoreState>,
     protected objectCache: ObjectCacheService,
     protected halService: HALEndpointService,
-    protected notificationsService: NotificationsService,
-    protected http: HttpClient,
-    protected comparator: DSOChangeAnalyzer<Bitstream>,
     protected bundleService: BundleDataService,
-    protected bitstreamFormatService: BitstreamFormatDataService
+    protected bitstreamFormatService: BitstreamFormatDataService,
+    protected comparator: DSOChangeAnalyzer<Bitstream>,
+    protected notificationsService: NotificationsService,
   ) {
-    super();
+    super('bitstreams', requestService, rdbService, objectCache, halService);
+
+    this.searchData = new SearchDataImpl(this.linkPath, requestService, rdbService, objectCache, halService, this.responseMsToLive);
+    this.patchData = new PatchDataImpl<Bitstream>(this.linkPath, requestService, rdbService, objectCache, halService, comparator, this.responseMsToLive, this.constructIdEndpoint);
+    this.deleteData = new DeleteDataImpl(this.linkPath, requestService, rdbService, objectCache, halService, notificationsService, this.responseMsToLive, this.constructIdEndpoint);
   }
 
   /**
@@ -73,7 +77,7 @@ export class BitstreamDataService extends DataService<Bitstream> {
    *                                    {@link HALLink}s should be automatically resolved
    */
   findAllByBundle(bundle: Bundle, options?: FindListOptions, useCachedVersionIfAvailable = true, reRequestOnStale = true, ...linksToFollow: FollowLinkConfig<Bitstream>[]): Observable<RemoteData<PaginatedList<Bitstream>>> {
-    return this.findAllByHref(bundle._links.bitstreams.href, options, useCachedVersionIfAvailable, reRequestOnStale, ...linksToFollow);
+    return this.findListByHref(bundle._links.bitstreams.href, options, useCachedVersionIfAvailable, reRequestOnStale, ...linksToFollow);
   }
 
   /**
@@ -180,8 +184,97 @@ export class BitstreamDataService extends DataService<Bitstream> {
       hrefObs,
       useCachedVersionIfAvailable,
       reRequestOnStale,
-      ...linksToFollow
+      ...linksToFollow,
     );
   }
 
+  /**
+   * Create the HREF for a specific object's search method with given options object
+   *
+   * @param searchMethod The search method for the object
+   * @param options The [[FindListOptions]] object
+   * @return {Observable<string>}
+   *    Return an observable that emits created HREF
+   * @param linksToFollow   List of {@link FollowLinkConfig} that indicate which {@link HALLink}s should be automatically resolved
+   */
+  public getSearchByHref(searchMethod: string, options?: FindListOptions, ...linksToFollow: FollowLinkConfig<Bitstream>[]): Observable<string> {
+    return this.searchData.getSearchByHref(searchMethod, options, ...linksToFollow);
+  }
+
+  /**
+   * Make a new FindListRequest with given search method
+   *
+   * @param searchMethod                The search method for the object
+   * @param options                     The [[FindListOptions]] object
+   * @param useCachedVersionIfAvailable If this is true, the request will only be sent if there's
+   *                                    no valid cached version. Defaults to true
+   * @param reRequestOnStale            Whether or not the request should automatically be re-
+   *                                    requested after the response becomes stale
+   * @param linksToFollow               List of {@link FollowLinkConfig} that indicate which
+   *                                    {@link HALLink}s should be automatically resolved
+   * @return {Observable<RemoteData<PaginatedList<T>>}
+   *    Return an observable that emits response from the server
+   */
+  public searchBy(searchMethod: string, options?: FindListOptions, useCachedVersionIfAvailable?: boolean, reRequestOnStale?: boolean, ...linksToFollow: FollowLinkConfig<Bitstream>[]): Observable<RemoteData<PaginatedList<Bitstream>>> {
+    return this.searchData.searchBy(searchMethod, options, useCachedVersionIfAvailable, reRequestOnStale, ...linksToFollow);
+  }
+
+  /**
+   * Commit current object changes to the server
+   * @param method The RestRequestMethod for which de server sync buffer should be committed
+   */
+  public commitUpdates(method?: RestRequestMethod): void {
+    this.patchData.commitUpdates(method);
+  }
+
+  /**
+   * Send a patch request for a specified object
+   * @param {T} object The object to send a patch request for
+   * @param {Operation[]} operations The patch operations to be performed
+   */
+  public patch(object: Bitstream, operations: []): Observable<RemoteData<Bitstream>> {
+    return this.patchData.patch(object, operations);
+  }
+
+  /**
+   * Add a new patch to the object cache
+   * The patch is derived from the differences between the given object and its version in the object cache
+   * @param {DSpaceObject} object The given object
+   */
+  public update(object: Bitstream): Observable<RemoteData<Bitstream>> {
+    return this.patchData.update(object);
+  }
+
+  /**
+   * Return a list of operations representing the difference between an object and its latest value in the cache.
+   * @param object  the object to resolve to a list of patch operations
+   */
+  public createPatchFromCache(object: Bitstream): Observable<Operation[]> {
+    return this.patchData.createPatchFromCache(object);
+  }
+
+  /**
+   * Delete an existing object on the server
+   * @param   objectId The id of the object to be removed
+   * @param   copyVirtualMetadata (optional parameter) the identifiers of the relationship types for which the virtual
+   *                            metadata should be saved as real metadata
+   * @return  A RemoteData observable with an empty payload, but still representing the state of the request: statusCode,
+   *          errorMessage, timeCompleted, etc
+   */
+  delete(objectId: string, copyVirtualMetadata?: string[]): Observable<RemoteData<NoContent>> {
+    return this.deleteData.delete(objectId, copyVirtualMetadata);
+  }
+
+  /**
+   * Delete an existing object on the server
+   * @param   href The self link of the object to be removed
+   * @param   copyVirtualMetadata (optional parameter) the identifiers of the relationship types for which the virtual
+   *                            metadata should be saved as real metadata
+   * @return  A RemoteData observable with an empty payload, but still representing the state of the request: statusCode,
+   *          errorMessage, timeCompleted, etc
+   *          Only emits once all request related to the DSO has been invalidated.
+   */
+  deleteByHref(href: string, copyVirtualMetadata?: string[]): Observable<RemoteData<NoContent>> {
+    return this.deleteData.deleteByHref(href, copyVirtualMetadata);
+  }
 }

src/app/core/data/bitstream-format-data.service.spec.ts

@@ -6,19 +6,16 @@ import { ObjectCacheService } from '../cache/object-cache.service';
 import { cold, getTestScheduler, hot } from 'jasmine-marbles';
 import { HALEndpointService } from '../shared/hal-endpoint.service';
 import { NotificationsService } from '../../shared/notifications/notifications.service';
-import { HttpClient } from '@angular/common/http';
 import { RemoteDataBuildService } from '../cache/builders/remote-data-build.service';
 import { BitstreamFormat } from '../shared/bitstream-format.model';
 import { waitForAsync } from '@angular/core/testing';
-import {
+import { BitstreamFormatsRegistryDeselectAction, BitstreamFormatsRegistryDeselectAllAction, BitstreamFormatsRegistrySelectAction } from '../../admin/admin-registries/bitstream-formats/bitstream-format.actions';
-  BitstreamFormatsRegistryDeselectAction,
-  BitstreamFormatsRegistryDeselectAllAction,
-  BitstreamFormatsRegistrySelectAction
-} from '../../admin/admin-registries/bitstream-formats/bitstream-format.actions';
 import { TestScheduler } from 'rxjs/testing';
 import { createSuccessfulRemoteDataObject } from '../../shared/remote-data.utils';
 import { CoreState } from '../core-state.model';
 import { RequestEntry } from './request-entry.model';
+import { testFindAllDataImplementation } from './base/find-all-data.spec';
+import { testDeleteDataImplementation } from './base/delete-data.spec';
 
 describe('BitstreamFormatDataService', () => {
   let service: BitstreamFormatDataService;
@@ -50,8 +47,6 @@ describe('BitstreamFormatDataService', () => {
   } as HALEndpointService;
 
   const notificationsService = {} as NotificationsService;
-  const http = {} as HttpClient;
-  const comparator = {} as any;
 
   let rd;
   let rdbService: RemoteDataBuildService;
@@ -65,15 +60,19 @@ describe('BitstreamFormatDataService', () => {
     return new BitstreamFormatDataService(
       requestService,
       rdbService,
-      store,
       objectCache,
       halService,
       notificationsService,
-      http,
+      store,
-      comparator
     );
   }
 
+  describe('composition', () => {
+    const initService = () => new BitstreamFormatDataService(null, null, null, null, null, null);
+    testFindAllDataImplementation(initService);
+    testDeleteDataImplementation(initService);
+  });
+
   describe('getBrowseEndpoint', () => {
     beforeEach(waitForAsync(() => {
       scheduler = getTestScheduler();

src/app/core/data/bitstream-format-data.service.ts

@@ -1,16 +1,10 @@
-import { HttpClient } from '@angular/common/http';
 import { Injectable } from '@angular/core';
 import { createSelector, select, Store } from '@ngrx/store';
 import { Observable } from 'rxjs';
 import { distinctUntilChanged, map, tap } from 'rxjs/operators';
-import {
+import { BitstreamFormatsRegistryDeselectAction, BitstreamFormatsRegistryDeselectAllAction, BitstreamFormatsRegistrySelectAction } from '../../admin/admin-registries/bitstream-formats/bitstream-format.actions';
-  BitstreamFormatsRegistryDeselectAction,
-  BitstreamFormatsRegistryDeselectAllAction,
-  BitstreamFormatsRegistrySelectAction
-} from '../../admin/admin-registries/bitstream-formats/bitstream-format.actions';
 import { BitstreamFormatRegistryState } from '../../admin/admin-registries/bitstream-formats/bitstream-format.reducers';
 import { NotificationsService } from '../../shared/notifications/notifications.service';
-import { dataService } from '../cache/builders/build-decorators';
 import { RemoteDataBuildService } from '../cache/builders/remote-data-build.service';
 import { ObjectCacheService } from '../cache/object-cache.service';
 import { coreSelector } from '../core.selectors';
@@ -18,40 +12,53 @@ import { BitstreamFormat } from '../shared/bitstream-format.model';
 import { BITSTREAM_FORMAT } from '../shared/bitstream-format.resource-type';
 import { Bitstream } from '../shared/bitstream.model';
 import { HALEndpointService } from '../shared/hal-endpoint.service';
-import { DataService } from './data.service';
-import { DefaultChangeAnalyzer } from './default-change-analyzer.service';
 import { RemoteData } from './remote-data';
 import { PostRequest, PutRequest } from './request.models';
 import { RequestService } from './request.service';
 import { sendRequest } from '../shared/request.operators';
 import { CoreState } from '../core-state.model';
+import { IdentifiableDataService } from './base/identifiable-data.service';
+import { DeleteData, DeleteDataImpl } from './base/delete-data';
+import { FindAllData, FindAllDataImpl } from './base/find-all-data';
+import { FollowLinkConfig } from 'src/app/shared/utils/follow-link-config.model';
+import { FindListOptions } from './find-list-options.model';
+import { PaginatedList } from './paginated-list.model';
+import { NoContent } from '../shared/NoContent.model';
+import { dataService } from './base/data-service.decorator';
 
 const bitstreamFormatsStateSelector = createSelector(
   coreSelector,
-  (state: CoreState) => state.bitstreamFormats
+  (state: CoreState) => state.bitstreamFormats,
+);
+const selectedBitstreamFormatSelector = createSelector(
+  bitstreamFormatsStateSelector,
+  (bitstreamFormatRegistryState: BitstreamFormatRegistryState) => bitstreamFormatRegistryState.selectedBitstreamFormats,
 );
-const selectedBitstreamFormatSelector = createSelector(bitstreamFormatsStateSelector,
-  (bitstreamFormatRegistryState: BitstreamFormatRegistryState) => bitstreamFormatRegistryState.selectedBitstreamFormats);
 
 /**
  * A service responsible for fetching/sending data from/to the REST API on the bitstreamformats endpoint
  */
 @Injectable()
 @dataService(BITSTREAM_FORMAT)
-export class BitstreamFormatDataService extends DataService<BitstreamFormat> {
+export class BitstreamFormatDataService extends IdentifiableDataService<BitstreamFormat> implements FindAllData<BitstreamFormat>, DeleteData<BitstreamFormat> {
 
   protected linkPath = 'bitstreamformats';
 
+  private findAllData: FindAllDataImpl<BitstreamFormat>;
+  private deleteData: DeleteDataImpl<BitstreamFormat>;
+
   constructor(
     protected requestService: RequestService,
     protected rdbService: RemoteDataBuildService,
-    protected store: Store<CoreState>,
     protected objectCache: ObjectCacheService,
     protected halService: HALEndpointService,
     protected notificationsService: NotificationsService,
-    protected http: HttpClient,
+    protected store: Store<CoreState>,
-    protected comparator: DefaultChangeAnalyzer<BitstreamFormat>) {
+  ) {
-    super();
+    super('bitstreamformats', requestService, rdbService, objectCache, halService);
+
+    this.findAllData = new FindAllDataImpl(this.linkPath, requestService, rdbService, objectCache, halService, this.responseMsToLive);
+    this.deleteData = new DeleteDataImpl(this.linkPath, requestService, rdbService, objectCache, halService, notificationsService, this.responseMsToLive, this.constructIdEndpoint);
   }
 
   /**
@@ -60,7 +67,7 @@ export class BitstreamFormatDataService extends DataService<BitstreamFormat> {
    */
   public getUpdateEndpoint(formatId: string): Observable<string> {
     return this.getBrowseEndpoint().pipe(
-      map((endpoint: string) => this.getIDHref(endpoint, formatId))
+      map((endpoint: string) => this.getIDHref(endpoint, formatId)),
     );
   }
 
@@ -147,4 +154,47 @@ export class BitstreamFormatDataService extends DataService<BitstreamFormat> {
   findByBitstream(bitstream: Bitstream): Observable<RemoteData<BitstreamFormat>> {
     return this.findByHref(bitstream._links.format.href);
   }
+
+  /**
+   * Returns {@link RemoteData} of all object with a list of {@link FollowLinkConfig}, to indicate which embedded
+   * info should be added to the objects
+   *
+   * @param options                     Find list options object
+   * @param useCachedVersionIfAvailable If this is true, the request will only be sent if there's
+   *                                    no valid cached version. Defaults to true
+   * @param reRequestOnStale            Whether or not the request should automatically be re-
+   *                                    requested after the response becomes stale
+   * @param linksToFollow               List of {@link FollowLinkConfig} that indicate which
+   *                                    {@link HALLink}s should be automatically resolved
+   * @return {Observable<RemoteData<PaginatedList<T>>>}
+   *    Return an observable that emits object list
+   */
+  findAll(options?: FindListOptions, useCachedVersionIfAvailable?: boolean, reRequestOnStale?: boolean, ...linksToFollow: FollowLinkConfig<BitstreamFormat>[]): Observable<RemoteData<PaginatedList<BitstreamFormat>>> {
+    return this.findAllData.findAll(options, useCachedVersionIfAvailable, reRequestOnStale, ...linksToFollow);
+  }
+
+  /**
+   * Delete an existing object on the server
+   * @param   objectId The id of the object to be removed
+   * @param   copyVirtualMetadata (optional parameter) the identifiers of the relationship types for which the virtual
+   *                            metadata should be saved as real metadata
+   * @return  A RemoteData observable with an empty payload, but still representing the state of the request: statusCode,
+   *          errorMessage, timeCompleted, etc
+   */
+  delete(objectId: string, copyVirtualMetadata?: string[]): Observable<RemoteData<NoContent>> {
+    return this.deleteData.delete(objectId, copyVirtualMetadata);
+  }
+
+  /**
+   * Delete an existing object on the server
+   * @param   href The self link of the object to be removed
+   * @param   copyVirtualMetadata (optional parameter) the identifiers of the relationship types for which the virtual
+   *                            metadata should be saved as real metadata
+   * @return  A RemoteData observable with an empty payload, but still representing the state of the request: statusCode,
+   *          errorMessage, timeCompleted, etc
+   *          Only emits once all request related to the DSO has been invalidated.
+   */
+  deleteByHref(href: string, copyVirtualMetadata?: string[]): Observable<RemoteData<NoContent>> {
+    return this.deleteData.deleteByHref(href, copyVirtualMetadata);
+  }
 }

src/app/core/data/bundle-data.service.spec.ts

@@ -13,6 +13,7 @@ import { createSuccessfulRemoteDataObject$ } from '../../shared/remote-data.util
 import { createPaginatedList } from '../../shared/testing/utils.test';
 import { Bundle } from '../shared/bundle.model';
 import { CoreState } from '../core-state.model';
+import { testPatchDataImplementation } from './base/patch-data.spec';
 
 class DummyChangeAnalyzer implements ChangeAnalyzer<Item> {
   diff(object1: Item, object2: Item): Operation[] {
@@ -64,9 +65,6 @@ describe('BundleDataService', () => {
       store,
       objectCache,
       halService,
-      notificationsService,
-      http,
-      comparator,
     );
   }
 
@@ -74,14 +72,20 @@ describe('BundleDataService', () => {
     service = initTestService();
   });
 
+  describe('composition', () => {
+    const initService = () => new BundleDataService(null, null, null, null, null);
+
+    testPatchDataImplementation(initService);
+  });
+
   describe('findAllByItem', () => {
     beforeEach(() => {
-      spyOn(service, 'findAllByHref');
+      spyOn(service, 'findListByHref');
       service.findAllByItem(item);
     });
 
-    it('should call findAllByHref with the item\'s bundles link', () => {
+    it('should call findListByHref with the item\'s bundles link', () => {
-      expect(service.findAllByHref).toHaveBeenCalledWith(bundleLink, undefined, true, true);
+      expect(service.findListByHref).toHaveBeenCalledWith(bundleLink, undefined, true, true);
     });
   });
 

src/app/core/data/bundle-data.service.ts

@@ -1,20 +1,14 @@
-import { HttpClient } from '@angular/common/http';
 import { Injectable } from '@angular/core';
-import { Store } from '@ngrx/store';
 import { Observable } from 'rxjs';
 import { map, switchMap, take } from 'rxjs/operators';
 import { hasValue } from '../../shared/empty.util';
-import { NotificationsService } from '../../shared/notifications/notifications.service';
 import { FollowLinkConfig } from '../../shared/utils/follow-link-config.model';
-import { dataService } from '../cache/builders/build-decorators';
 import { RemoteDataBuildService } from '../cache/builders/remote-data-build.service';
 import { ObjectCacheService } from '../cache/object-cache.service';
 import { Bundle } from '../shared/bundle.model';
 import { BUNDLE } from '../shared/bundle.resource-type';
 import { HALEndpointService } from '../shared/hal-endpoint.service';
 import { Item } from '../shared/item.model';
-import { DataService } from './data.service';
-import { DefaultChangeAnalyzer } from './default-change-analyzer.service';
 import { PaginatedList } from './paginated-list.model';
 import { RemoteData } from './remote-data';
 import { GetRequest } from './request.models';
@@ -22,30 +16,36 @@ import { RequestService } from './request.service';
 import { PaginatedSearchOptions } from '../../shared/search/models/paginated-search-options.model';
 import { Bitstream } from '../shared/bitstream.model';
 import { RequestEntryState } from './request-entry-state.model';
-import { CoreState } from '../core-state.model';
 import { FindListOptions } from './find-list-options.model';
+import { IdentifiableDataService } from './base/identifiable-data.service';
+import { PatchData, PatchDataImpl } from './base/patch-data';
+import { DSOChangeAnalyzer } from './dso-change-analyzer.service';
+import { RestRequestMethod } from './rest-request-method';
+import { Operation } from 'fast-json-patch';
+import { dataService } from './base/data-service.decorator';
 
 /**
  * A service to retrieve {@link Bundle}s from the REST API
  */
 @Injectable(
-  {providedIn: 'root'}
+  { providedIn: 'root' },
 )
 @dataService(BUNDLE)
-export class BundleDataService extends DataService<Bundle> {
+export class BundleDataService extends IdentifiableDataService<Bundle> implements PatchData<Bundle> {
-  protected linkPath = 'bundles';
+  private bitstreamsEndpoint = 'bitstreams';
-  protected bitstreamsEndpoint = 'bitstreams';
+
+  private patchData: PatchDataImpl<Bundle>;
 
   constructor(
     protected requestService: RequestService,
     protected rdbService: RemoteDataBuildService,
-    protected store: Store<CoreState>,
     protected objectCache: ObjectCacheService,
     protected halService: HALEndpointService,
-    protected notificationsService: NotificationsService,
+    protected comparator: DSOChangeAnalyzer<Bundle>,
-    protected http: HttpClient,
+  ) {
-    protected comparator: DefaultChangeAnalyzer<Bundle>) {
+    super('bundles', requestService, rdbService, objectCache, halService);
-    super();
+
+    this.patchData = new PatchDataImpl<Bundle>(this.linkPath, requestService, rdbService, objectCache, halService, comparator, this.responseMsToLive, this.constructIdEndpoint);
   }
 
   /**
@@ -61,7 +61,7 @@ export class BundleDataService extends DataService<Bundle> {
    *                                    {@link HALLink}s should be automatically resolved
    */
   findAllByItem(item: Item, options?: FindListOptions, useCachedVersionIfAvailable = true, reRequestOnStale = true, ...linksToFollow: FollowLinkConfig<Bundle>[]): Observable<RemoteData<PaginatedList<Bundle>>> {
-    return this.findAllByHref(item._links.bundles.href, options, useCachedVersionIfAvailable, reRequestOnStale, ...linksToFollow);
+    return this.findListByHref(item._links.bundles.href, options, useCachedVersionIfAvailable, reRequestOnStale, ...linksToFollow);
   }
 
   /**
@@ -133,7 +133,7 @@ export class BundleDataService extends DataService<Bundle> {
     const hrefObs = this.getBitstreamsEndpoint(bundleId, searchOptions);
 
     hrefObs.pipe(
-      take(1)
+      take(1),
     ).subscribe((href) => {
       const request = new GetRequest(this.requestService.generateRequestId(), href);
       this.requestService.send(request, true);
@@ -141,4 +141,38 @@ export class BundleDataService extends DataService<Bundle> {
 
     return this.rdbService.buildList<Bitstream>(hrefObs, ...linksToFollow);
   }
+
+  /**
+   * Commit current object changes to the server
+   * @param method The RestRequestMethod for which de server sync buffer should be committed
+   */
+  public commitUpdates(method?: RestRequestMethod): void {
+    this.patchData.commitUpdates(method);
+  }
+
+  /**
+   * Send a patch request for a specified object
+   * @param {T} object The object to send a patch request for
+   * @param {Operation[]} operations The patch operations to be performed
+   */
+  public patch(object: Bundle, operations: Operation[]): Observable<RemoteData<Bundle>> {
+    return this.patchData.patch(object, operations);
+  }
+
+  /**
+   * Add a new patch to the object cache
+   * The patch is derived from the differences between the given object and its version in the object cache
+   * @param {DSpaceObject} object The given object
+   */
+  public update(object: Bundle): Observable<RemoteData<Bundle>> {
+    return this.patchData.update(object);
+  }
+
+  /**
+   * Return a list of operations representing the difference between an object and its latest value in the cache.
+   * @param object  the object to resolve to a list of patch operations
+   */
+  public createPatchFromCache(object: Bundle): Observable<Operation[]> {
+    return this.patchData.createPatchFromCache(object);
+  }
 }

src/app/core/data/collection-data.service.spec.ts

@@ -13,16 +13,17 @@ import { RemoteDataBuildService } from '../cache/builders/remote-data-build.serv
 import { Collection } from '../shared/collection.model';
 import { PageInfo } from '../shared/page-info.model';
 import { buildPaginatedList } from './paginated-list.model';
-import {
+import { createFailedRemoteDataObject$, createSuccessfulRemoteDataObject, createSuccessfulRemoteDataObject$ } from '../../shared/remote-data.utils';
-  createFailedRemoteDataObject$,
-  createSuccessfulRemoteDataObject,
-  createSuccessfulRemoteDataObject$
-} from '../../shared/remote-data.utils';
 import { cold, getTestScheduler, hot } from 'jasmine-marbles';
 import { TestScheduler } from 'rxjs/testing';
 import { Observable } from 'rxjs';
 import { RemoteData } from './remote-data';
 import { hasNoValue } from '../../shared/empty.util';
+import { testCreateDataImplementation } from './base/create-data.spec';
+import { testFindAllDataImplementation } from './base/find-all-data.spec';
+import { testSearchDataImplementation } from './base/search-data.spec';
+import { testPatchDataImplementation } from './base/patch-data.spec';
+import { testDeleteDataImplementation } from './base/delete-data.spec';
 
 const url = 'fake-url';
 const collectionId = 'fake-collection-id';
@@ -75,6 +76,16 @@ describe('CollectionDataService', () => {
   const paginatedList = buildPaginatedList(pageInfo, array);
   const paginatedListRD = createSuccessfulRemoteDataObject(paginatedList);
 
+  describe('composition', () => {
+    const initService = () => new CollectionDataService(null, null, null, null, null, null, null, null, null);
+
+    testCreateDataImplementation(initService);
+    testFindAllDataImplementation(initService);
+    testSearchDataImplementation(initService);
+    testPatchDataImplementation(initService);
+    testDeleteDataImplementation(initService);
+  });
+
   describe('when the requests are successful', () => {
     beforeEach(() => {
       createService();
@@ -201,7 +212,7 @@ describe('CollectionDataService', () => {
     notificationsService = new NotificationsServiceStub();
     translate = getMockTranslateService();
 
-    service = new CollectionDataService(requestService, rdbService, null, null, objectCache, halService, notificationsService, null, null, null, translate);
+    service = new CollectionDataService(requestService, rdbService, objectCache, halService, null, notificationsService, null, null, translate);
   }
 
 });

src/app/core/data/collection-data.service.ts

@@ -1,6 +1,5 @@
-import { HttpClient, HttpHeaders } from '@angular/common/http';
+import { HttpHeaders } from '@angular/common/http';
 import { Injectable } from '@angular/core';
-import { Store } from '@ngrx/store';
 import { TranslateService } from '@ngx-translate/core';
 import { Observable } from 'rxjs';
 import { filter, map, switchMap, take } from 'rxjs/operators';
@@ -9,7 +8,6 @@ import { NotificationOptions } from '../../shared/notifications/models/notificat
 import { INotification } from '../../shared/notifications/models/notification.model';
 import { NotificationsService } from '../../shared/notifications/notifications.service';
 import { FollowLinkConfig } from '../../shared/utils/follow-link-config.model';
-import { dataService } from '../cache/builders/build-decorators';
 import { RemoteDataBuildService } from '../cache/builders/remote-data-build.service';
 import { RequestParam } from '../cache/models/request-param.model';
 import { ObjectCacheService } from '../cache/object-cache.service';
@@ -33,30 +31,28 @@ import {
 import { RequestService } from './request.service';
 import { BitstreamDataService } from './bitstream-data.service';
 import { RestRequest } from './rest-request.model';
-import { CoreState } from '../core-state.model';
 import { FindListOptions } from './find-list-options.model';
+import { Community } from '../shared/community.model';
+import { dataService } from './base/data-service.decorator';
 
 @Injectable()
 @dataService(COLLECTION)
 export class CollectionDataService extends ComColDataService<Collection> {
-  protected linkPath = 'collections';
   protected errorTitle = 'collection.source.update.notifications.error.title';
   protected contentSourceError = 'collection.source.update.notifications.error.content';
 
   constructor(
     protected requestService: RequestService,
     protected rdbService: RemoteDataBuildService,
-    protected store: Store<CoreState>,
-    protected cds: CommunityDataService,
     protected objectCache: ObjectCacheService,
     protected halService: HALEndpointService,
+    protected comparator: DSOChangeAnalyzer<Community>,
     protected notificationsService: NotificationsService,
-    protected http: HttpClient,
     protected bitstreamDataService: BitstreamDataService,
-    protected comparator: DSOChangeAnalyzer<Collection>,
+    protected communityDataService: CommunityDataService,
-    protected translate: TranslateService
+    protected translate: TranslateService,
   ) {
-    super();
+    super('collections', requestService, rdbService, objectCache, halService, comparator, notificationsService, bitstreamDataService);
   }
 
   /**
@@ -284,15 +280,15 @@ export class CollectionDataService extends ComColDataService<Collection> {
    * @param findListOptions Pagination and search options.
    */
   findMappedCollectionsFor(item: Item, findListOptions?: FindListOptions): Observable<RemoteData<PaginatedList<Collection>>> {
-    return this.findAllByHref(item._links.mappedCollections.href, findListOptions);
+    return this.findListByHref(item._links.mappedCollections.href, findListOptions);
   }
 
 
   protected getScopeCommunityHref(options: FindListOptions) {
-    return this.cds.getEndpoint().pipe(
+    return this.communityDataService.getEndpoint().pipe(
-      map((endpoint: string) => this.cds.getIDHref(endpoint, options.scopeID)),
+      map((endpoint: string) => this.communityDataService.getIDHref(endpoint, options.scopeID)),
       filter((href: string) => isNotEmpty(href)),
-      take(1)
+      take(1),
     );
   }
 }

src/app/core/data/comcol-data.service.spec.ts

@@ -13,16 +13,16 @@ import { ComColDataService } from './comcol-data.service';
 import { CommunityDataService } from './community-data.service';
 import { DSOChangeAnalyzer } from './dso-change-analyzer.service';
 import { RequestService } from './request.service';
-import {
+import { createFailedRemoteDataObject, createFailedRemoteDataObject$, createSuccessfulRemoteDataObject, createSuccessfulRemoteDataObject$ } from '../../shared/remote-data.utils';
-  createFailedRemoteDataObject$,
-  createSuccessfulRemoteDataObject$,
-  createFailedRemoteDataObject,
-  createSuccessfulRemoteDataObject
-} from '../../shared/remote-data.utils';
 import { BitstreamDataService } from './bitstream-data.service';
 import { CoreState } from '../core-state.model';
 import { FindListOptions } from './find-list-options.model';
 import { Bitstream } from '../shared/bitstream.model';
+import { testCreateDataImplementation } from './base/create-data.spec';
+import { testFindAllDataImplementation } from './base/find-all-data.spec';
+import { testSearchDataImplementation } from './base/search-data.spec';
+import { testPatchDataImplementation } from './base/patch-data.spec';
+import { testDeleteDataImplementation } from './base/delete-data.spec';
 
 const LINK_NAME = 'test';
 
@@ -47,7 +47,7 @@ class TestService extends ComColDataService<any> {
     protected comparator: DSOChangeAnalyzer<Community>,
     protected linkPath: string
   ) {
-    super();
+    super('something', requestService, rdbService, objectCache, halService, comparator, notificationsService, bitstreamDataService);
   }
 
   protected getFindByParentHref(parentUUID: string): Observable<string> {
@@ -154,6 +154,15 @@ describe('ComColDataService', () => {
     service = initTestService();
   });
 
+  describe('composition', () => {
+    const initService = () => new TestService(null, null, null, null, null, null, null, null, null, null, null);
+    testCreateDataImplementation(initService);
+    testFindAllDataImplementation(initService);
+    testSearchDataImplementation(initService);
+    testPatchDataImplementation(initService);
+    testDeleteDataImplementation(initService);
+  });
+
   describe('getBrowseEndpoint', () => {
     it(`should call createAndSendGetRequest with the scope Community's self link`, () => {
       testScheduler.run(({ cold, flush, expectObservable }) => {

src/app/core/data/comcol-data.service.ts

@@ -4,7 +4,6 @@ import { hasValue, isEmpty, isNotEmpty } from '../../shared/empty.util';
 import { ObjectCacheService } from '../cache/object-cache.service';
 import { Community } from '../shared/community.model';
 import { HALLink } from '../shared/hal-link.model';
-import { DataService } from './data.service';
 import { PaginatedList } from './paginated-list.model';
 import { RemoteData } from './remote-data';
 import { HALEndpointService } from '../shared/hal-endpoint.service';
@@ -17,11 +16,45 @@ import { createFailedRemoteDataObject$ } from '../../shared/remote-data.utils';
 import { URLCombiner } from '../url-combiner/url-combiner';
 import { FollowLinkConfig } from '../../shared/utils/follow-link-config.model';
 import { FindListOptions } from './find-list-options.model';
+import { IdentifiableDataService } from './base/identifiable-data.service';
+import { PatchData, PatchDataImpl } from './base/patch-data';
+import { DeleteData, DeleteDataImpl } from './base/delete-data';
+import { FindAllData, FindAllDataImpl } from './base/find-all-data';
+import { SearchData, SearchDataImpl } from './base/search-data';
+import { RestRequestMethod } from './rest-request-method';
+import { CreateData, CreateDataImpl } from './base/create-data';
+import { RequestParam } from '../cache/models/request-param.model';
+import { RequestService } from './request.service';
+import { RemoteDataBuildService } from '../cache/builders/remote-data-build.service';
+import { NotificationsService } from '../../shared/notifications/notifications.service';
+import { DSOChangeAnalyzer } from './dso-change-analyzer.service';
+import { Operation } from 'fast-json-patch';
 
-export abstract class ComColDataService<T extends Community | Collection> extends DataService<T> {
+export abstract class ComColDataService<T extends Community | Collection> extends IdentifiableDataService<T> implements CreateData<T>, FindAllData<T>, SearchData<T>, PatchData<T>, DeleteData<T> {
-  protected abstract objectCache: ObjectCacheService;
+  private createData: CreateData<T>;
-  protected abstract halService: HALEndpointService;
+  private findAllData: FindAllData<T>;
-  protected abstract bitstreamDataService: BitstreamDataService;
+  private searchData: SearchData<T>;
+  private patchData: PatchData<T>;
+  private deleteData: DeleteData<T>;
+
+  protected constructor(
+    protected linkPath: string,
+    protected requestService: RequestService,
+    protected rdbService: RemoteDataBuildService,
+    protected objectCache: ObjectCacheService,
+    protected halService: HALEndpointService,
+    protected comparator: DSOChangeAnalyzer<T>,
+    protected notificationsService: NotificationsService,
+    protected bitstreamDataService: BitstreamDataService,
+  ) {
+    super(linkPath, requestService, rdbService, objectCache, halService);
+
+    this.createData = new CreateDataImpl(this.linkPath, requestService, rdbService, objectCache, halService, notificationsService, this.responseMsToLive);
+    this.findAllData = new FindAllDataImpl(this.linkPath, requestService, rdbService, objectCache, halService, this.responseMsToLive);
+    this.searchData = new SearchDataImpl<T>(this.linkPath, requestService, rdbService, objectCache, halService, this.responseMsToLive);
+    this.patchData = new PatchDataImpl<T>(this.linkPath, requestService, rdbService, objectCache, halService, comparator, this.responseMsToLive, this.constructIdEndpoint);
+    this.deleteData = new DeleteDataImpl(this.linkPath, requestService, rdbService, objectCache, halService, notificationsService, this.responseMsToLive, this.constructIdEndpoint);
+  }
 
   /**
    * Get the scoped endpoint URL by fetching the object with
@@ -66,7 +99,7 @@ export abstract class ComColDataService<T extends Community | Collection> extend
     const href$ = this.getFindByParentHref(parentUUID).pipe(
       map((href: string) => this.buildHrefFromFindOptions(href, options))
     );
-    return this.findAllByHref(href$, options, true, true, ...linksToFollow);
+    return this.findListByHref(href$, options, true, true, ...linksToFollow);
   }
 
   /**
@@ -129,4 +162,110 @@ export abstract class ComColDataService<T extends Community | Collection> extend
     const parentCommunity = dso._links.parentCommunity;
     return isNotEmpty(parentCommunity) ? parentCommunity.href : null;
   }
+
+
+  /**
+   * Create a new object on the server, and store the response in the object cache
+   *
+   * @param object    The object to create
+   * @param params    Array with additional params to combine with query string
+   */
+  create(object: T, ...params: RequestParam[]): Observable<RemoteData<T>> {
+    return this.createData.create(object, ...params);
+  }
+
+  /**
+   * Returns {@link RemoteData} of all object with a list of {@link FollowLinkConfig}, to indicate which embedded
+   * info should be added to the objects
+   *
+   * @param options                     Find list options object
+   * @param useCachedVersionIfAvailable If this is true, the request will only be sent if there's
+   *                                    no valid cached version. Defaults to true
+   * @param reRequestOnStale            Whether or not the request should automatically be re-
+   *                                    requested after the response becomes stale
+   * @param linksToFollow               List of {@link FollowLinkConfig} that indicate which
+   *                                    {@link HALLink}s should be automatically resolved
+   * @return {Observable<RemoteData<PaginatedList<T>>>}
+   *    Return an observable that emits object list
+   */
+  public findAll(options?: FindListOptions, useCachedVersionIfAvailable?: boolean, reRequestOnStale?: boolean, ...linksToFollow: FollowLinkConfig<T>[]): Observable<RemoteData<PaginatedList<T>>> {
+    return this.findAllData.findAll(options, useCachedVersionIfAvailable, reRequestOnStale, ...linksToFollow);
+  }
+
+  /**
+   * Make a new FindListRequest with given search method
+   *
+   * @param searchMethod                The search method for the object
+   * @param options                     The [[FindListOptions]] object
+   * @param useCachedVersionIfAvailable If this is true, the request will only be sent if there's
+   *                                    no valid cached version. Defaults to true
+   * @param reRequestOnStale            Whether or not the request should automatically be re-
+   *                                    requested after the response becomes stale
+   * @param linksToFollow               List of {@link FollowLinkConfig} that indicate which
+   *                                    {@link HALLink}s should be automatically resolved
+   * @return {Observable<RemoteData<PaginatedList<T>>}
+   *    Return an observable that emits response from the server
+   */
+  public searchBy(searchMethod: string, options?: FindListOptions, useCachedVersionIfAvailable?: boolean, reRequestOnStale?: boolean, ...linksToFollow: FollowLinkConfig<T>[]): Observable<RemoteData<PaginatedList<T>>> {
+    return this.searchData.searchBy(searchMethod, options, useCachedVersionIfAvailable, reRequestOnStale, ...linksToFollow);
+  }
+
+  /**
+   * Commit current object changes to the server
+   * @param method The RestRequestMethod for which de server sync buffer should be committed
+   */
+  public commitUpdates(method?: RestRequestMethod): void {
+    this.patchData.commitUpdates(method);
+  }
+
+  /**
+   * Send a patch request for a specified object
+   * @param {T} object The object to send a patch request for
+   * @param {Operation[]} operations The patch operations to be performed
+   */
+  public patch(object: T, operations: []): Observable<RemoteData<T>> {
+    return this.patchData.patch(object, operations);
+  }
+
+  /**
+   * Add a new patch to the object cache
+   * The patch is derived from the differences between the given object and its version in the object cache
+   * @param {DSpaceObject} object The given object
+   */
+  public update(object: T): Observable<RemoteData<T>> {
+    return this.patchData.update(object);
+  }
+
+  /**
+   * Return a list of operations representing the difference between an object and its latest value in the cache.
+   * @param object  the object to resolve to a list of patch operations
+   */
+  public createPatchFromCache(object: T): Observable<Operation[]> {
+    return this.patchData.createPatchFromCache(object);
+  }
+
+  /**
+   * Delete an existing object on the server
+   * @param   objectId The id of the object to be removed
+   * @param   copyVirtualMetadata (optional parameter) the identifiers of the relationship types for which the virtual
+   *                            metadata should be saved as real metadata
+   * @return  A RemoteData observable with an empty payload, but still representing the state of the request: statusCode,
+   *          errorMessage, timeCompleted, etc
+   */
+  public delete(objectId: string, copyVirtualMetadata?: string[]): Observable<RemoteData<NoContent>> {
+    return this.deleteData.delete(objectId, copyVirtualMetadata);
+  }
+
+  /**
+   * Delete an existing object on the server
+   * @param   href The self link of the object to be removed
+   * @param   copyVirtualMetadata (optional parameter) the identifiers of the relationship types for which the virtual
+   *                            metadata should be saved as real metadata
+   * @return  A RemoteData observable with an empty payload, but still representing the state of the request: statusCode,
+   *          errorMessage, timeCompleted, etc
+   *          Only emits once all request related to the DSO has been invalidated.
+   */
+  public deleteByHref(href: string, copyVirtualMetadata?: string[]): Observable<RemoteData<NoContent>> {
+    return this.deleteData.deleteByHref(href, copyVirtualMetadata);
+  }
 }

src/app/core/data/community-data.service.ts

@@ -1,11 +1,8 @@
-import { HttpClient } from '@angular/common/http';
 import { Injectable } from '@angular/core';
 
-import { Store } from '@ngrx/store';
 import { Observable } from 'rxjs';
 import { filter, map, switchMap, take } from 'rxjs/operators';
 import { NotificationsService } from '../../shared/notifications/notifications.service';
-import { dataService } from '../cache/builders/build-decorators';
 import { RemoteDataBuildService } from '../cache/builders/remote-data-build.service';
 import { ObjectCacheService } from '../cache/object-cache.service';
 import { Community } from '../shared/community.model';
@@ -19,36 +16,36 @@ import { RequestService } from './request.service';
 import { BitstreamDataService } from './bitstream-data.service';
 import { FollowLinkConfig } from '../../shared/utils/follow-link-config.model';
 import { isNotEmpty } from '../../shared/empty.util';
-import { CoreState } from '../core-state.model';
 import { FindListOptions } from './find-list-options.model';
+import { dataService } from './base/data-service.decorator';
 
 @Injectable()
 @dataService(COMMUNITY)
 export class CommunityDataService extends ComColDataService<Community> {
-  protected linkPath = 'communities';
   protected topLinkPath = 'search/top';
 
   constructor(
     protected requestService: RequestService,
     protected rdbService: RemoteDataBuildService,
-    protected store: Store<CoreState>,
     protected objectCache: ObjectCacheService,
     protected halService: HALEndpointService,
+    protected comparator: DSOChangeAnalyzer<Community>,
     protected notificationsService: NotificationsService,
     protected bitstreamDataService: BitstreamDataService,
-    protected http: HttpClient,
-    protected comparator: DSOChangeAnalyzer<Community>
   ) {
-    super();
+    super('communities', requestService, rdbService, objectCache, halService, comparator, notificationsService, bitstreamDataService);
   }
 
+  // this method is overridden in order to make it public
   getEndpoint() {
     return this.halService.getEndpoint(this.linkPath);
   }
 
   findTop(options: FindListOptions = {}, ...linksToFollow: FollowLinkConfig<Community>[]): Observable<RemoteData<PaginatedList<Community>>> {
-    const hrefObs = this.getFindAllHref(options, this.topLinkPath);
+    return this.getEndpoint().pipe(
-    return this.findAllByHref(hrefObs, undefined, true, true, ...linksToFollow);
+      map(href => `${href}/search/top`),
+      switchMap(href => this.findListByHref(href, options, true, true, ...linksToFollow))
+    );
   }
 
   protected getFindByParentHref(parentUUID: string): Observable<string> {

src/app/core/data/configuration-data.service.spec.ts

@@ -5,8 +5,6 @@ import { HALEndpointService } from '../shared/hal-endpoint.service';
 import { GetRequest } from './request.models';
 import { RequestService } from './request.service';
 import { ObjectCacheService } from '../cache/object-cache.service';
-import { NotificationsService } from '../../shared/notifications/notifications.service';
-import { HttpClient } from '@angular/common/http';
 import { ConfigurationDataService } from './configuration-data.service';
 import { ConfigurationProperty } from '../shared/configuration-property.model';
 
@@ -44,18 +42,12 @@ describe('ConfigurationDataService', () => {
       })
     });
     objectCache = {} as ObjectCacheService;
-    const notificationsService = {} as NotificationsService;
-    const http = {} as HttpClient;
-    const comparator = {} as any;
 
     service = new ConfigurationDataService(
       requestService,
       rdbService,
       objectCache,
       halService,
-      notificationsService,
-      http,
-      comparator
     );
   });
 

src/app/core/data/configuration-data.service.ts

@@ -1,55 +1,30 @@
 /* eslint-disable max-classes-per-file */
-import { HttpClient } from '@angular/common/http';
 import { Injectable } from '@angular/core';
-import { Store } from '@ngrx/store';
 import { Observable } from 'rxjs';
-import { NotificationsService } from '../../shared/notifications/notifications.service';
-import { dataService } from '../cache/builders/build-decorators';
 import { RemoteDataBuildService } from '../cache/builders/remote-data-build.service';
 import { ObjectCacheService } from '../cache/object-cache.service';
 import { HALEndpointService } from '../shared/hal-endpoint.service';
-import { DataService } from './data.service';
 import { RemoteData } from './remote-data';
 import { RequestService } from './request.service';
 import { ConfigurationProperty } from '../shared/configuration-property.model';
-import { DefaultChangeAnalyzer } from './default-change-analyzer.service';
 import { CONFIG_PROPERTY } from '../shared/config-property.resource-type';
-import { CoreState } from '../core-state.model';
+import { IdentifiableDataService } from './base/identifiable-data.service';
-
+import { dataService } from './base/data-service.decorator';
-class DataServiceImpl extends DataService<ConfigurationProperty> {
-  protected linkPath = 'properties';
-
-  constructor(
-    protected requestService: RequestService,
-    protected rdbService: RemoteDataBuildService,
-    protected store: Store<CoreState>,
-    protected objectCache: ObjectCacheService,
-    protected halService: HALEndpointService,
-    protected notificationsService: NotificationsService,
-    protected http: HttpClient,
-    protected comparator: DefaultChangeAnalyzer<ConfigurationProperty>) {
-    super();
-  }
-}
 
 @Injectable()
 @dataService(CONFIG_PROPERTY)
 /**
  * Data Service responsible for retrieving Configuration properties
  */
-export class ConfigurationDataService {
+export class ConfigurationDataService extends IdentifiableDataService<ConfigurationProperty> {
-  protected linkPath = 'properties';
-  private dataService: DataServiceImpl;
 
   constructor(
     protected requestService: RequestService,
     protected rdbService: RemoteDataBuildService,
     protected objectCache: ObjectCacheService,
     protected halService: HALEndpointService,
-    protected notificationsService: NotificationsService,
+  ) {
-    protected http: HttpClient,
+    super('properties', requestService, rdbService, objectCache, halService);
-    protected comparator: DefaultChangeAnalyzer<ConfigurationProperty>) {
-    this.dataService = new DataServiceImpl(requestService, rdbService, null, objectCache, halService, notificationsService, http, comparator);
   }
 
   /**
@@ -57,6 +32,6 @@ export class ConfigurationDataService {
    * @param name
    */
   findByPropertyName(name: string): Observable<RemoteData<ConfigurationProperty>> {
-    return this.dataService.findById(name);
+    return this.findById(name);
   }
 }

src/app/core/data/data.service.ts

@@ -1,702 +0,0 @@
-import { HttpClient } from '@angular/common/http';
-import { Store } from '@ngrx/store';
-import { Operation } from 'fast-json-patch';
-import { AsyncSubject, from as observableFrom, Observable, of as observableOf } from 'rxjs';
-import {
-  distinctUntilChanged,
-  filter,
-  find,
-  map,
-  mergeMap,
-  skipWhile,
-  switchMap,
-  take,
-  takeWhile,
-  tap,
-  toArray
-} from 'rxjs/operators';
-import { hasValue, isNotEmpty, isNotEmptyOperator } from '../../shared/empty.util';
-import { NotificationOptions } from '../../shared/notifications/models/notification-options.model';
-import { NotificationsService } from '../../shared/notifications/notifications.service';
-import { FollowLinkConfig } from '../../shared/utils/follow-link-config.model';
-import { getClassForType } from '../cache/builders/build-decorators';
-import { RemoteDataBuildService } from '../cache/builders/remote-data-build.service';
-import { RequestParam } from '../cache/models/request-param.model';
-import { ObjectCacheEntry } from '../cache/object-cache.reducer';
-import { ObjectCacheService } from '../cache/object-cache.service';
-import { DSpaceSerializer } from '../dspace-rest/dspace.serializer';
-import { DSpaceObject } from '../shared/dspace-object.model';
-import { HALEndpointService } from '../shared/hal-endpoint.service';
-import { getFirstCompletedRemoteData, getFirstSucceededRemoteData, getRemoteDataPayload } from '../shared/operators';
-import { URLCombiner } from '../url-combiner/url-combiner';
-import { ChangeAnalyzer } from './change-analyzer';
-import { PaginatedList } from './paginated-list.model';
-import { RemoteData } from './remote-data';
-import { CreateRequest, DeleteRequest, GetRequest, PatchRequest, PutRequest } from './request.models';
-import { RequestService } from './request.service';
-import { RestRequestMethod } from './rest-request-method';
-import { UpdateDataService } from './update-data.service';
-import { GenericConstructor } from '../shared/generic-constructor';
-import { NoContent } from '../shared/NoContent.model';
-import { CacheableObject } from '../cache/cacheable-object.model';
-import { CoreState } from '../core-state.model';
-import { FindListOptions } from './find-list-options.model';
-
-export abstract class DataService<T extends CacheableObject> implements UpdateDataService<T> {
-  protected abstract requestService: RequestService;
-  protected abstract rdbService: RemoteDataBuildService;
-  protected abstract store: Store<CoreState>;
-  protected abstract linkPath: string;
-  protected abstract halService: HALEndpointService;
-  protected abstract objectCache: ObjectCacheService;
-  protected abstract notificationsService: NotificationsService;
-  protected abstract http: HttpClient;
-  protected abstract comparator: ChangeAnalyzer<T>;
-
-  /**
-   * Allows subclasses to reset the response cache time.
-   */
-  protected responseMsToLive: number;
-
-  /**
-   * Get the endpoint for browsing
-   * @param options The [[FindListOptions]] object
-   * @param linkPath The link path for the object
-   * @returns {Observable<string>}
-   */
-  getBrowseEndpoint(options: FindListOptions = {}, linkPath?: string): Observable<string> {
-    return this.getEndpoint();
-  }
-
-  /**
-   * Get the base endpoint for all requests
-   */
-  protected getEndpoint(): Observable<string> {
-    return this.halService.getEndpoint(this.linkPath);
-  }
-
-  /**
-   * Create the HREF with given options object
-   *
-   * @param options The [[FindListOptions]] object
-   * @param linkPath The link path for the object
-   * @return {Observable<string>}
-   *    Return an observable that emits created HREF
-   * @param linksToFollow   List of {@link FollowLinkConfig} that indicate which {@link HALLink}s should be automatically resolved
-   */
-  public getFindAllHref(options: FindListOptions = {}, linkPath?: string, ...linksToFollow: FollowLinkConfig<T>[]): Observable<string> {
-    let endpoint$: Observable<string>;
-    const args = [];
-
-    endpoint$ = this.getBrowseEndpoint(options).pipe(
-      filter((href: string) => isNotEmpty(href)),
-      map((href: string) => isNotEmpty(linkPath) ? `${href}/${linkPath}` : href),
-      distinctUntilChanged()
-    );
-
-    return endpoint$.pipe(map((result: string) => this.buildHrefFromFindOptions(result, options, args, ...linksToFollow)));
-  }
-
-  /**
-   * Create the HREF for a specific object's search method with given options object
-   *
-   * @param searchMethod The search method for the object
-   * @param options The [[FindListOptions]] object
-   * @return {Observable<string>}
-   *    Return an observable that emits created HREF
-   * @param linksToFollow   List of {@link FollowLinkConfig} that indicate which {@link HALLink}s should be automatically resolved
-   */
-  public getSearchByHref(searchMethod: string, options: FindListOptions = {}, ...linksToFollow: FollowLinkConfig<T>[]): Observable<string> {
-    let result$: Observable<string>;
-    const args = [];
-
-    result$ = this.getSearchEndpoint(searchMethod);
-
-    return result$.pipe(map((result: string) => this.buildHrefFromFindOptions(result, options, args, ...linksToFollow)));
-  }
-
-  /**
-   * Turn an options object into a query string and combine it with the given HREF
-   *
-   * @param href The HREF to which the query string should be appended
-   * @param options The [[FindListOptions]] object
-   * @param extraArgs Array with additional params to combine with query string
-   * @return {Observable<string>}
-   *    Return an observable that emits created HREF
-   * @param linksToFollow   List of {@link FollowLinkConfig} that indicate which {@link HALLink}s should be automatically resolved
-   */
-  public buildHrefFromFindOptions(href: string, options: FindListOptions, extraArgs: string[] = [], ...linksToFollow: FollowLinkConfig<T>[]): string {
-    let args = [...extraArgs];
-
-    if (hasValue(options.currentPage) && typeof options.currentPage === 'number') {
-      /* TODO: this is a temporary fix for the pagination start index (0 or 1) discrepancy between the rest and the frontend respectively */
-      args = this.addHrefArg(href, args, `page=${options.currentPage - 1}`);
-    }
-    if (hasValue(options.elementsPerPage)) {
-      args = this.addHrefArg(href, args, `size=${options.elementsPerPage}`);
-    }
-    if (hasValue(options.sort)) {
-      args = this.addHrefArg(href, args, `sort=${options.sort.field},${options.sort.direction}`);
-    }
-    if (hasValue(options.startsWith)) {
-      args = this.addHrefArg(href, args, `startsWith=${options.startsWith}`);
-    }
-    if (hasValue(options.searchParams)) {
-      options.searchParams.forEach((param: RequestParam) => {
-        args = this.addHrefArg(href, args, `${param.fieldName}=${param.fieldValue}`);
-      });
-    }
-    args = this.addEmbedParams(href, args, ...linksToFollow);
-    if (isNotEmpty(args)) {
-      return new URLCombiner(href, `?${args.join('&')}`).toString();
-    } else {
-      return href;
-    }
-  }
-
-  /**
-   * Turn an array of RequestParam into a query string and combine it with the given HREF
-   *
-   * @param href The HREF to which the query string should be appended
-   * @param params Array with additional params to combine with query string
-   * @param linksToFollow   List of {@link FollowLinkConfig} that indicate which {@link HALLink}s should be automatically resolved
-   *
-   * @return {Observable<string>}
-   * Return an observable that emits created HREF
-   */
-  buildHrefWithParams(href: string, params: RequestParam[], ...linksToFollow: FollowLinkConfig<T>[]): string {
-
-    let args = [];
-    if (hasValue(params)) {
-      params.forEach((param: RequestParam) => {
-        args = this.addHrefArg(href, args, `${param.fieldName}=${param.fieldValue}`);
-      });
-    }
-
-    args = this.addEmbedParams(href, args, ...linksToFollow);
-
-    if (isNotEmpty(args)) {
-      return new URLCombiner(href, `?${args.join('&')}`).toString();
-    } else {
-      return href;
-    }
-  }
-
-  /**
-   * Adds the embed options to the link for the request
-   * @param href            The href the params are to be added to
-   * @param args            params for the query string
-   * @param linksToFollow   links we want to embed in query string if shouldEmbed is true
-   */
-  protected addEmbedParams(href: string, args: string[], ...linksToFollow: FollowLinkConfig<T>[]) {
-    linksToFollow.forEach((linkToFollow: FollowLinkConfig<T>) => {
-      if (hasValue(linkToFollow) && linkToFollow.shouldEmbed) {
-        const embedString = 'embed=' + String(linkToFollow.name);
-        // Add the embeds size if given in the FollowLinkConfig.FindListOptions
-        if (hasValue(linkToFollow.findListOptions) && hasValue(linkToFollow.findListOptions.elementsPerPage)) {
-          args = this.addHrefArg(href, args,
-            'embed.size=' + String(linkToFollow.name) + '=' + linkToFollow.findListOptions.elementsPerPage);
-        }
-        // Adds the nested embeds and their size if given
-        if (isNotEmpty(linkToFollow.linksToFollow)) {
-          args = this.addNestedEmbeds(embedString, href, args, ...linkToFollow.linksToFollow);
-        } else {
-          args = this.addHrefArg(href, args, embedString);
-        }
-      }
-    });
-    return args;
-  }
-
-  /**
-   * Add a new argument to the list of arguments, only if it doesn't already exist in the given href,
-   * or the current list of arguments
-   *
-   * @param href        The href the arguments are to be added to
-   * @param currentArgs The current list of arguments
-   * @param newArg      The new argument to add
-   * @return            The next list of arguments, with newArg included if it wasn't already.
-   *                    Note this function will not modify any of the input params.
-   */
-  protected addHrefArg(href: string, currentArgs: string[], newArg: string): string[] {
-    if (href.includes(newArg) || currentArgs.includes(newArg)) {
-      return [...currentArgs];
-    } else {
-      return [...currentArgs, newArg];
-    }
-  }
-
-  /**
-   * Add the nested followLinks to the embed param, separated by a /, and their sizes, recursively
-   * @param embedString     embedString so far (recursive)
-   * @param href            The href the params are to be added to
-   * @param args            params for the query string
-   * @param linksToFollow   links we want to embed in query string if shouldEmbed is true
-   */
-  protected addNestedEmbeds(embedString: string, href: string, args: string[], ...linksToFollow: FollowLinkConfig<T>[]): string[] {
-    let nestEmbed = embedString;
-    linksToFollow.forEach((linkToFollow: FollowLinkConfig<T>) => {
-      if (hasValue(linkToFollow) && linkToFollow.shouldEmbed) {
-        nestEmbed = nestEmbed + '/' + String(linkToFollow.name);
-        // Add the nested embeds size if given in the FollowLinkConfig.FindListOptions
-        if (hasValue(linkToFollow.findListOptions) && hasValue(linkToFollow.findListOptions.elementsPerPage)) {
-          const nestedEmbedSize = 'embed.size=' + nestEmbed.split('=')[1] + '=' + linkToFollow.findListOptions.elementsPerPage;
-          args = this.addHrefArg(href, args, nestedEmbedSize);
-        }
-        if (hasValue(linkToFollow.linksToFollow) && isNotEmpty(linkToFollow.linksToFollow)) {
-          args = this.addNestedEmbeds(nestEmbed, href, args, ...linkToFollow.linksToFollow);
-        } else {
-          args = this.addHrefArg(href, args, nestEmbed);
-        }
-      }
-    });
-    return args;
-  }
-
-  /**
-   * Returns {@link RemoteData} of all object with a list of {@link FollowLinkConfig}, to indicate which embedded
-   * info should be added to the objects
-   *
-   * @param options                     Find list options object
-   * @param useCachedVersionIfAvailable If this is true, the request will only be sent if there's
-   *                                    no valid cached version. Defaults to true
-   * @param reRequestOnStale            Whether or not the request should automatically be re-
-   *                                    requested after the response becomes stale
-   * @param linksToFollow               List of {@link FollowLinkConfig} that indicate which
-   *                                    {@link HALLink}s should be automatically resolved
-   * @return {Observable<RemoteData<PaginatedList<T>>>}
-   *    Return an observable that emits object list
-   */
-  findAll(options: FindListOptions = {}, useCachedVersionIfAvailable = true, reRequestOnStale = true, ...linksToFollow: FollowLinkConfig<T>[]): Observable<RemoteData<PaginatedList<T>>> {
-    return this.findAllByHref(this.getFindAllHref(options), options, useCachedVersionIfAvailable, reRequestOnStale, ...linksToFollow);
-  }
-
-  /**
-   * Create the HREF for a specific object based on its identifier; with possible embed query params based on linksToFollow
-   * @param endpoint The base endpoint for the type of object
-   * @param resourceID The identifier for the object
-   * @param linksToFollow   List of {@link FollowLinkConfig} that indicate which {@link HALLink}s should be automatically resolved
-   */
-  getIDHref(endpoint, resourceID, ...linksToFollow: FollowLinkConfig<T>[]): string {
-    return this.buildHrefFromFindOptions(endpoint + '/' + resourceID, {}, [], ...linksToFollow);
-  }
-
-  /**
-   * Create an observable for the HREF of a specific object based on its identifier
-   * @param resourceID The identifier for the object
-   * @param linksToFollow   List of {@link FollowLinkConfig} that indicate which {@link HALLink}s should be automatically resolved
-   */
-  getIDHrefObs(resourceID: string, ...linksToFollow: FollowLinkConfig<T>[]): Observable<string> {
-    return this.getEndpoint().pipe(
-      map((endpoint: string) => this.getIDHref(endpoint, resourceID, ...linksToFollow)));
-  }
-
-  /**
-   * Returns an observable of {@link RemoteData} of an object, based on its ID, with a list of
-   * {@link FollowLinkConfig}, to automatically resolve {@link HALLink}s of the object
-   * @param id                          ID of object we want to retrieve
-   * @param useCachedVersionIfAvailable If this is true, the request will only be sent if there's
-   *                                    no valid cached version. Defaults to true
-   * @param reRequestOnStale            Whether or not the request should automatically be re-
-   *                                    requested after the response becomes stale
-   * @param linksToFollow               List of {@link FollowLinkConfig} that indicate which
-   *                                    {@link HALLink}s should be automatically resolved
-   */
-  findById(id: string, useCachedVersionIfAvailable = true, reRequestOnStale = true, ...linksToFollow: FollowLinkConfig<T>[]): Observable<RemoteData<T>> {
-    const href$ = this.getIDHrefObs(encodeURIComponent(id), ...linksToFollow);
-    return this.findByHref(href$, useCachedVersionIfAvailable, reRequestOnStale, ...linksToFollow);
-  }
-
-  /**
-   * An operator that will call the given function if the incoming RemoteData is stale and
-   * shouldReRequest is true
-   *
-   * @param shouldReRequest  Whether or not to call the re-request function if the RemoteData is stale
-   * @param requestFn        The function to call if the RemoteData is stale and shouldReRequest is
-   *                         true
-   */
-  protected reRequestStaleRemoteData<O>(shouldReRequest: boolean, requestFn: () => Observable<RemoteData<O>>) {
-    return (source: Observable<RemoteData<O>>): Observable<RemoteData<O>> => {
-      if (shouldReRequest === true) {
-        return source.pipe(
-          tap((remoteData: RemoteData<O>) => {
-            if (hasValue(remoteData) && remoteData.isStale) {
-              requestFn();
-            }
-          })
-        );
-      } else {
-        return source;
-      }
-    };
-  }
-
-  /**
-   * Returns an observable of {@link RemoteData} of an object, based on an href, with a list of
-   * {@link FollowLinkConfig}, to automatically resolve {@link HALLink}s of the object
-   * @param href$                       The url of object we want to retrieve. Can be a string or
-   *                                    an Observable<string>
-   * @param useCachedVersionIfAvailable If this is true, the request will only be sent if there's
-   *                                    no valid cached version. Defaults to true
-   * @param reRequestOnStale            Whether or not the request should automatically be re-
-   *                                    requested after the response becomes stale
-   * @param linksToFollow               List of {@link FollowLinkConfig} that indicate which
-   *                                    {@link HALLink}s should be automatically resolved
-   */
-  findByHref(href$: string | Observable<string>, useCachedVersionIfAvailable = true, reRequestOnStale = true, ...linksToFollow: FollowLinkConfig<T>[]): Observable<RemoteData<T>> {
-    if (typeof href$ === 'string') {
-      href$ = observableOf(href$);
-    }
-
-    const requestHref$ = href$.pipe(
-      isNotEmptyOperator(),
-      take(1),
-      map((href: string) => this.buildHrefFromFindOptions(href, {}, [], ...linksToFollow))
-    );
-
-    this.createAndSendGetRequest(requestHref$, useCachedVersionIfAvailable);
-
-    return this.rdbService.buildSingle<T>(requestHref$, ...linksToFollow).pipe(
-      // This skip ensures that if a stale object is present in the cache when you do a
-      // call it isn't immediately returned, but we wait until the remote data for the new request
-      // is created. If useCachedVersionIfAvailable is false it also ensures you don't get a
-      // cached completed object
-      skipWhile((rd: RemoteData<T>) => useCachedVersionIfAvailable ? rd.isStale : rd.hasCompleted),
-      this.reRequestStaleRemoteData(reRequestOnStale, () =>
-        this.findByHref(href$, useCachedVersionIfAvailable, reRequestOnStale, ...linksToFollow))
-    );
-  }
-
-  /**
-   * Returns a list of observables of {@link RemoteData} of objects, based on an href, with a list
-   * of {@link FollowLinkConfig}, to automatically resolve {@link HALLink}s of the object
-   * @param href$                       The url of object we want to retrieve. Can be a string or
-   *                                    an Observable<string>
-   * @param findListOptions             Find list options object
-   * @param useCachedVersionIfAvailable If this is true, the request will only be sent if there's
-   *                                    no valid cached version. Defaults to true
-   * @param reRequestOnStale            Whether or not the request should automatically be re-
-   *                                    requested after the response becomes stale
-   * @param linksToFollow               List of {@link FollowLinkConfig} that indicate which
-   *                                    {@link HALLink}s should be automatically resolved
-   */
-  findAllByHref(href$: string | Observable<string>, findListOptions: FindListOptions = {}, useCachedVersionIfAvailable = true, reRequestOnStale = true, ...linksToFollow: FollowLinkConfig<T>[]): Observable<RemoteData<PaginatedList<T>>> {
-    if (typeof href$ === 'string') {
-      href$ = observableOf(href$);
-    }
-
-    const requestHref$ = href$.pipe(
-      isNotEmptyOperator(),
-      take(1),
-      map((href: string) => this.buildHrefFromFindOptions(href, findListOptions, [], ...linksToFollow))
-    );
-
-    this.createAndSendGetRequest(requestHref$, useCachedVersionIfAvailable);
-
-    return this.rdbService.buildList<T>(requestHref$, ...linksToFollow).pipe(
-      // This skip ensures that if a stale object is present in the cache when you do a
-      // call it isn't immediately returned, but we wait until the remote data for the new request
-      // is created. If useCachedVersionIfAvailable is false it also ensures you don't get a
-      // cached completed object
-      skipWhile((rd: RemoteData<PaginatedList<T>>) => useCachedVersionIfAvailable ? rd.isStale : rd.hasCompleted),
-      this.reRequestStaleRemoteData(reRequestOnStale, () =>
-        this.findAllByHref(href$, findListOptions, useCachedVersionIfAvailable, reRequestOnStale, ...linksToFollow))
-    );
-  }
-
-  /**
-   * Create a GET request for the given href, and send it.
-   *
-   * @param href$                       The url of object we want to retrieve. Can be a string or
-   *                                    an Observable<string>
-   * @param useCachedVersionIfAvailable If this is true, the request will only be sent if there's
-   *                                    no valid cached version. Defaults to true
-   */
-  protected createAndSendGetRequest(href$: string | Observable<string>, useCachedVersionIfAvailable = true): void {
-    if (isNotEmpty(href$)) {
-      if (typeof href$ === 'string') {
-        href$ = observableOf(href$);
-      }
-
-      href$.pipe(
-        isNotEmptyOperator(),
-        take(1)
-      ).subscribe((href: string) => {
-        const requestId = this.requestService.generateRequestId();
-        const request = new GetRequest(requestId, href);
-        if (hasValue(this.responseMsToLive)) {
-          request.responseMsToLive = this.responseMsToLive;
-        }
-        this.requestService.send(request, useCachedVersionIfAvailable);
-      });
-    }
-  }
-
-  /**
-   * Return object search endpoint by given search method
-   *
-   * @param searchMethod The search method for the object
-   */
-  protected getSearchEndpoint(searchMethod: string): Observable<string> {
-    return this.halService.getEndpoint(this.linkPath).pipe(
-      filter((href: string) => isNotEmpty(href)),
-      map((href: string) => `${href}/search/${searchMethod}`));
-  }
-
-  /**
-   * Make a new FindListRequest with given search method
-   *
-   * @param searchMethod                The search method for the object
-   * @param options                     The [[FindListOptions]] object
-   * @param useCachedVersionIfAvailable If this is true, the request will only be sent if there's
-   *                                    no valid cached version. Defaults to true
-   * @param reRequestOnStale            Whether or not the request should automatically be re-
-   *                                    requested after the response becomes stale
-   * @param linksToFollow               List of {@link FollowLinkConfig} that indicate which
-   *                                    {@link HALLink}s should be automatically resolved
-   * @return {Observable<RemoteData<PaginatedList<T>>}
-   *    Return an observable that emits response from the server
-   */
-  searchBy(searchMethod: string, options: FindListOptions = {}, useCachedVersionIfAvailable = true, reRequestOnStale = true, ...linksToFollow: FollowLinkConfig<T>[]): Observable<RemoteData<PaginatedList<T>>> {
-    const hrefObs = this.getSearchByHref(searchMethod, options, ...linksToFollow);
-
-    return this.findAllByHref(hrefObs, undefined, useCachedVersionIfAvailable, reRequestOnStale, ...linksToFollow);
-  }
-
-  /**
-   * Send a patch request for a specified object
-   * @param {T} object The object to send a patch request for
-   * @param {Operation[]} operations The patch operations to be performed
-   */
-  patch(object: T, operations: Operation[]): Observable<RemoteData<T>> {
-    const requestId = this.requestService.generateRequestId();
-
-    const hrefObs = this.halService.getEndpoint(this.linkPath).pipe(
-      map((endpoint: string) => this.getIDHref(endpoint, object.uuid)));
-
-    hrefObs.pipe(
-      find((href: string) => hasValue(href)),
-    ).subscribe((href: string) => {
-      const request = new PatchRequest(requestId, href, operations);
-      if (hasValue(this.responseMsToLive)) {
-        request.responseMsToLive = this.responseMsToLive;
-      }
-      this.requestService.send(request);
-    });
-
-    return this.rdbService.buildFromRequestUUID(requestId);
-  }
-
-  createPatchFromCache(object: T): Observable<Operation[]> {
-    const oldVersion$ = this.findByHref(object._links.self.href, true, false);
-    return oldVersion$.pipe(
-      getFirstSucceededRemoteData(),
-      getRemoteDataPayload(),
-      map((oldVersion: T) => this.comparator.diff(oldVersion, object)));
-  }
-
-  /**
-   * Send a PUT request for the specified object
-   *
-   * @param object The object to send a put request for.
-   */
-  put(object: T): Observable<RemoteData<T>> {
-    const requestId = this.requestService.generateRequestId();
-    const serializedObject = new DSpaceSerializer(object.constructor as GenericConstructor<{}>).serialize(object);
-    const request = new PutRequest(requestId, object._links.self.href, serializedObject);
-
-    if (hasValue(this.responseMsToLive)) {
-      request.responseMsToLive = this.responseMsToLive;
-    }
-
-    this.requestService.send(request);
-
-    return this.rdbService.buildFromRequestUUID(requestId);
-  }
-
-  /**
-   * Add a new patch to the object cache
-   * The patch is derived from the differences between the given object and its version in the object cache
-   * @param {DSpaceObject} object The given object
-   */
-  update(object: T): Observable<RemoteData<T>> {
-    return this.createPatchFromCache(object)
-      .pipe(
-        mergeMap((operations: Operation[]) => {
-            if (isNotEmpty(operations)) {
-              this.objectCache.addPatch(object._links.self.href, operations);
-            }
-            return this.findByHref(object._links.self.href, true, true);
-          }
-        )
-      );
-  }
-
-  /**
-   * Create a new DSpaceObject on the server, and store the response
-   * in the object cache
-   *
-   * @param {CacheableObject} object
-   *    The object to create
-   * @param {RequestParam[]} params
-   *    Array with additional params to combine with query string
-   */
-  create(object: T, ...params: RequestParam[]): Observable<RemoteData<T>> {
-    const requestId = this.requestService.generateRequestId();
-    const endpoint$ = this.getEndpoint().pipe(
-      isNotEmptyOperator(),
-      distinctUntilChanged(),
-      map((endpoint: string) => this.buildHrefWithParams(endpoint, params))
-    );
-
-    const serializedObject = new DSpaceSerializer(getClassForType(object.type)).serialize(object);
-
-    endpoint$.pipe(
-      take(1)
-    ).subscribe((endpoint: string) => {
-      const request = new CreateRequest(requestId, endpoint, JSON.stringify(serializedObject));
-      if (hasValue(this.responseMsToLive)) {
-        request.responseMsToLive = this.responseMsToLive;
-      }
-      this.requestService.send(request);
-    });
-
-    const result$ = this.rdbService.buildFromRequestUUID<T>(requestId);
-
-    // TODO a dataservice is not the best place to show a notification,
-    // this should move up to the components that use this method
-    result$.pipe(
-      takeWhile((rd: RemoteData<T>) => rd.isLoading, true)
-    ).subscribe((rd: RemoteData<T>) => {
-      if (rd.hasFailed) {
-        this.notificationsService.error('Server Error:', rd.errorMessage, new NotificationOptions(-1));
-      }
-    });
-
-    return result$;
-  }
-
-  /**
-   * Invalidate an existing DSpaceObject by marking all requests it is included in as stale
-   * @param   objectId The id of the object to be invalidated
-   * @return  An Observable that will emit `true` once all requests are stale
-   */
-  invalidate(objectId: string): Observable<boolean> {
-    return this.getIDHrefObs(objectId).pipe(
-      switchMap((href: string) => this.invalidateByHref(href))
-    );
-  }
-
-  /**
-   * Invalidate an existing DSpaceObject by marking all requests it is included in as stale
-   * @param   href The self link of the object to be invalidated
-   * @return  An Observable that will emit `true` once all requests are stale
-   */
-  invalidateByHref(href: string): Observable<boolean> {
-    const done$ = new AsyncSubject<boolean>();
-
-    this.objectCache.getByHref(href).pipe(
-      take(1),
-      switchMap((oce: ObjectCacheEntry) => observableFrom(oce.requestUUIDs).pipe(
-        mergeMap((requestUUID: string) => this.requestService.setStaleByUUID(requestUUID)),
-        toArray(),
-      )),
-    ).subscribe(() => {
-      done$.next(true);
-      done$.complete();
-    });
-
-    return done$;
-  }
-
-  /**
-   * Delete an existing DSpace Object on the server
-   * @param   objectId The id of the object to be removed
-   * @param   copyVirtualMetadata (optional parameter) the identifiers of the relationship types for which the virtual
-   *                            metadata should be saved as real metadata
-   * @return  A RemoteData observable with an empty payload, but still representing the state of the request: statusCode,
-   *          errorMessage, timeCompleted, etc
-   */
-  delete(objectId: string, copyVirtualMetadata?: string[]): Observable<RemoteData<NoContent>> {
-    return this.getIDHrefObs(objectId).pipe(
-      switchMap((href: string) => this.deleteByHref(href, copyVirtualMetadata))
-    );
-  }
-
-  /**
-   * Delete an existing DSpace Object on the server
-   * @param   href The self link of the object to be removed
-   * @param   copyVirtualMetadata (optional parameter) the identifiers of the relationship types for which the virtual
-   *                            metadata should be saved as real metadata
-   * @return  A RemoteData observable with an empty payload, but still representing the state of the request: statusCode,
-   *          errorMessage, timeCompleted, etc
-   *          Only emits once all request related to the DSO has been invalidated.
-   */
-  deleteByHref(href: string, copyVirtualMetadata?: string[]): Observable<RemoteData<NoContent>> {
-    const requestId = this.requestService.generateRequestId();
-
-    if (copyVirtualMetadata) {
-      copyVirtualMetadata.forEach((id) =>
-        href += (href.includes('?') ? '&' : '?')
-          + 'copyVirtualMetadata='
-          + id
-      );
-    }
-
-    const request = new DeleteRequest(requestId, href);
-    if (hasValue(this.responseMsToLive)) {
-      request.responseMsToLive = this.responseMsToLive;
-    }
-    this.requestService.send(request);
-
-    const response$ = this.rdbService.buildFromRequestUUID(requestId);
-
-    const invalidated$ = new AsyncSubject<boolean>();
-    response$.pipe(
-      getFirstCompletedRemoteData(),
-      switchMap((rd: RemoteData<NoContent>) => {
-        if (rd.hasSucceeded) {
-          return this.invalidateByHref(href);
-        } else {
-          return [true];
-        }
-      })
-    ).subscribe(() => {
-      invalidated$.next(true);
-      invalidated$.complete();
-    });
-
-    return response$.pipe(
-      switchMap((rd: RemoteData<NoContent>) => {
-        if (rd.hasSucceeded) {
-          return invalidated$.pipe(
-            filter((invalidated: boolean) => invalidated),
-            map(() => rd)
-          );
-        } else {
-          return [rd];
-        }
-      })
-    );
-  }
-
-  /**
-   * Commit current object changes to the server
-   * @param method The RestRequestMethod for which de server sync buffer should be committed
-   */
-  commitUpdates(method?: RestRequestMethod) {
-    this.requestService.commit(method);
-  }
-
-  /**
-   * Return the links to traverse from the root of the api to the
-   * endpoint this DataService represents
-   *
-   * e.g. if the api root links to 'foo', and the endpoint at 'foo'
-   * links to 'bar' the linkPath for the BarDataService would be
-   * 'foo/bar'
-   */
-  getLinkPath(): string {
-    return this.linkPath;
-  }
-}

src/app/core/data/dso-redirect-data.service.ts

@@ -1,95 +0,0 @@
-import { HttpClient } from '@angular/common/http';
-import { Injectable } from '@angular/core';
-import { Router } from '@angular/router';
-import { Store } from '@ngrx/store';
-import { Observable } from 'rxjs';
-import { tap } from 'rxjs/operators';
-import { hasValue } from '../../shared/empty.util';
-import { NotificationsService } from '../../shared/notifications/notifications.service';
-import { FollowLinkConfig } from '../../shared/utils/follow-link-config.model';
-import { RemoteDataBuildService } from '../cache/builders/remote-data-build.service';
-import { ObjectCacheService } from '../cache/object-cache.service';
-import { HALEndpointService } from '../shared/hal-endpoint.service';
-import { DataService } from './data.service';
-import { DSOChangeAnalyzer } from './dso-change-analyzer.service';
-import { RemoteData } from './remote-data';
-import { IdentifierType } from './request.models';
-import { RequestService } from './request.service';
-import { getFirstCompletedRemoteData } from '../shared/operators';
-import { DSpaceObject } from '../shared/dspace-object.model';
-import { Item } from '../shared/item.model';
-import { getItemPageRoute } from '../../item-page/item-page-routing-paths';
-import { CoreState } from '../core-state.model';
-
-@Injectable()
-export class DsoRedirectDataService extends DataService<any> {
-
-  // Set the default link path to the identifier lookup endpoint.
-  protected linkPath = 'pid';
-  private uuidEndpoint = 'dso';
-
-  constructor(
-    protected requestService: RequestService,
-    protected rdbService: RemoteDataBuildService,
-    protected store: Store<CoreState>,
-    protected objectCache: ObjectCacheService,
-    protected halService: HALEndpointService,
-    protected notificationsService: NotificationsService,
-    protected http: HttpClient,
-    protected comparator: DSOChangeAnalyzer<any>,
-    private router: Router) {
-    super();
-  }
-
-  setLinkPath(identifierType: IdentifierType) {
-    // The default 'pid' endpoint for identifiers does not support uuid lookups.
-    // For uuid lookups we need to change the linkPath.
-    if (identifierType === IdentifierType.UUID) {
-      this.linkPath = this.uuidEndpoint;
-    }
-  }
-
-  getIDHref(endpoint, resourceID, ...linksToFollow: FollowLinkConfig<any>[]): string {
-    // Supporting both identifier (pid) and uuid (dso) endpoints
-    return this.buildHrefFromFindOptions( endpoint.replace(/\{\?id\}/, `?id=${resourceID}`)
-        .replace(/\{\?uuid\}/, `?uuid=${resourceID}`),
-      {}, [], ...linksToFollow);
-  }
-
-  findByIdAndIDType(id: string, identifierType = IdentifierType.UUID): Observable<RemoteData<DSpaceObject>> {
-    this.setLinkPath(identifierType);
-    return this.findById(id).pipe(
-      getFirstCompletedRemoteData(),
-      tap((response) => {
-        if (response.hasSucceeded) {
-          const dso = response.payload;
-          const uuid = dso.uuid;
-          if (hasValue(uuid)) {
-            let newRoute = this.getEndpointFromDSOType(response.payload.type);
-            if (dso.type.startsWith('item')) {
-              newRoute = getItemPageRoute(dso as Item);
-            } else if (hasValue(newRoute)) {
-              newRoute += '/' + uuid;
-            }
-            if (hasValue(newRoute)) {
-              this.router.navigate([newRoute]);
-            }
-          }
-        }
-      })
-    );
-  }
-  // Is there an existing method somewhere else that converts dso type to route?
-  getEndpointFromDSOType(dsoType: string): string {
-    // Are there other types to consider?
-    if (dsoType.startsWith('item')) {
-      return 'items';
-    } else if (dsoType.startsWith('community')) {
-      return 'communities';
-    } else if (dsoType.startsWith('collection')) {
-      return 'collections';
-    } else {
-      return '';
-    }
-  }
-}

src/app/core/data/dso-redirect.service.spec.ts

@@ -1,22 +1,18 @@
-import { HttpClient } from '@angular/common/http';
-import { Store } from '@ngrx/store';
 import { cold, getTestScheduler } from 'jasmine-marbles';
 import { TestScheduler } from 'rxjs/testing';
-import { NotificationsService } from '../../shared/notifications/notifications.service';
 import { followLink } from '../../shared/utils/follow-link-config.model';
 import { RemoteDataBuildService } from '../cache/builders/remote-data-build.service';
 import { ObjectCacheService } from '../cache/object-cache.service';
 import { HALEndpointService } from '../shared/hal-endpoint.service';
-import { DsoRedirectDataService } from './dso-redirect-data.service';
+import { DsoRedirectService } from './dso-redirect.service';
 import { GetRequest, IdentifierType } from './request.models';
 import { RequestService } from './request.service';
 import { createSuccessfulRemoteDataObject } from '../../shared/remote-data.utils';
 import { Item } from '../shared/item.model';
-import { CoreState } from '../core-state.model';
 
-describe('DsoRedirectDataService', () => {
+describe('DsoRedirectService', () => {
   let scheduler: TestScheduler;
-  let service: DsoRedirectDataService;
+  let service: DsoRedirectService;
   let halService: HALEndpointService;
   let requestService: RequestService;
   let rdbService: RemoteDataBuildService;
@@ -29,10 +25,6 @@ describe('DsoRedirectDataService', () => {
   const requestHandleURL = `https://rest.api/rest/api/pid/find?id=${encodedHandle}`;
   const requestUUIDURL = `https://rest.api/rest/api/pid/find?id=${dsoUUID}`;
   const requestUUID = '34cfed7c-f597-49ef-9cbe-ea351f0023c2';
-  const store = {} as Store<CoreState>;
-  const notificationsService = {} as NotificationsService;
-  const http = {} as HttpClient;
-  const comparator = {} as any;
   const objectCache = {} as ObjectCacheService;
 
   beforeEach(() => {
@@ -59,20 +51,16 @@ describe('DsoRedirectDataService', () => {
         a: remoteData
       })
     });
-    service = new DsoRedirectDataService(
+    service = new DsoRedirectService(
       requestService,
       rdbService,
-      store,
       objectCache,
       halService,
-      notificationsService,
+      router,
-      http,
-      comparator,
-      router
     );
   });
 
-  describe('findById', () => {
+  describe('findByIdAndIDType', () => {
     it('should call HALEndpointService with the path to the pid endpoint', () => {
       scheduler.schedule(() => service.findByIdAndIDType(dsoHandle, IdentifierType.HANDLE));
       scheduler.flush();
@@ -141,7 +129,7 @@ describe('DsoRedirectDataService', () => {
       redir.subscribe();
       scheduler.schedule(() => redir);
       scheduler.flush();
-      expect(router.navigate).toHaveBeenCalledWith([remoteData.payload.type + 's/' + remoteData.payload.uuid]);
+      expect(router.navigate).toHaveBeenCalledWith(['/collections/' + remoteData.payload.uuid]);
     });
 
     it('should navigate to communities route', () => {
@@ -150,55 +138,58 @@ describe('DsoRedirectDataService', () => {
       redir.subscribe();
       scheduler.schedule(() => redir);
       scheduler.flush();
-      expect(router.navigate).toHaveBeenCalledWith(['communities/' + remoteData.payload.uuid]);
+      expect(router.navigate).toHaveBeenCalledWith(['/communities/' + remoteData.payload.uuid]);
     });
   });
 
-  describe('getIDHref', () => {
+  describe('DataService', () => {  // todo: should only test the id/uuid interpolation thingy
+    describe('getIDHref', () => {  // todo: should be able to move this up to IdentifiableDataService?
       it('should return endpoint', () => {
-      const result = (service as any).getIDHref(pidLink, dsoUUID);
+        const result = (service as any).dataService.getIDHref(pidLink, dsoUUID);
         expect(result).toEqual(requestUUIDURL);
       });
 
       it('should include single linksToFollow as embed', () => {
         const expected = `${requestUUIDURL}&embed=bundles`;
-      const result = (service as any).getIDHref(pidLink, dsoUUID, followLink('bundles'));
+        const result = (service as any).dataService.getIDHref(pidLink, dsoUUID, followLink('bundles'));
         expect(result).toEqual(expected);
       });
 
       it('should include multiple linksToFollow as embed', () => {
         const expected = `${requestUUIDURL}&embed=bundles&embed=owningCollection&embed=templateItemOf`;
-      const result = (service as any).getIDHref(pidLink, dsoUUID, followLink('bundles'), followLink('owningCollection'), followLink('templateItemOf'));
+        const result = (service as any).dataService.getIDHref(pidLink, dsoUUID, followLink('bundles'), followLink('owningCollection'), followLink('templateItemOf'));
         expect(result).toEqual(expected);
       });
 
       it('should not include linksToFollow with shouldEmbed = false', () => {
         const expected = `${requestUUIDURL}&embed=templateItemOf`;
-      const result = (service as any).getIDHref(
+        const result = (service as any).dataService.getIDHref(
           pidLink,
           dsoUUID,
           followLink('bundles', { shouldEmbed: false }),
           followLink('owningCollection', { shouldEmbed: false }),
-        followLink('templateItemOf')
+          followLink('templateItemOf'),
         );
         expect(result).toEqual(expected);
       });
 
       it('should include nested linksToFollow 3lvl', () => {
         const expected = `${requestUUIDURL}&embed=owningCollection/itemtemplate/relationships`;
-      const result = (service as any).getIDHref(
+        const result = (service as any).dataService.getIDHref(
           pidLink,
           dsoUUID,
-        followLink('owningCollection',
+          followLink(
+            'owningCollection',
             {},
-          followLink('itemtemplate',
+            followLink(
+              'itemtemplate',
               {},
-            followLink('relationships')
+              followLink('relationships'),
-          )
+            ),
-        )
+          ),
         );
         expect(result).toEqual(expected);
       });
     });
-
+  });
 });

src/app/core/data/dso-redirect.service.ts

@@ -0,0 +1,104 @@
+/**
+ * The contents of this file are subject to the license and copyright
+ * detailed in the LICENSE and NOTICE files at the root of the source
+ * tree and available online at
+ *
+ * http://www.dspace.org/license/
+ */
+/* eslint-disable max-classes-per-file */
+import { Injectable } from '@angular/core';
+import { Router } from '@angular/router';
+import { Observable } from 'rxjs';
+import { tap } from 'rxjs/operators';
+import { hasValue } from '../../shared/empty.util';
+import { RemoteDataBuildService } from '../cache/builders/remote-data-build.service';
+import { ObjectCacheService } from '../cache/object-cache.service';
+import { HALEndpointService } from '../shared/hal-endpoint.service';
+import { RemoteData } from './remote-data';
+import { IdentifierType } from './request.models';
+import { RequestService } from './request.service';
+import { getFirstCompletedRemoteData } from '../shared/operators';
+import { DSpaceObject } from '../shared/dspace-object.model';
+import { IdentifiableDataService } from './base/identifiable-data.service';
+import { getDSORoute } from '../../app-routing-paths';
+
+const ID_ENDPOINT = 'pid';
+const UUID_ENDPOINT = 'dso';
+
+/**
+ * A data service to retrieve DSpaceObjects by persistent identifier or UUID.
+ * Doesn't define a constant {@link linkPath} but switches between two endpoints on demand:
+ * {@link setLinkPath} must be called before each request.
+ */
+class DsoByIdOrUUIDDataService extends IdentifiableDataService<DSpaceObject> {
+  constructor(
+    protected requestService: RequestService,
+    protected rdbService: RemoteDataBuildService,
+    protected objectCache: ObjectCacheService,
+    protected halService: HALEndpointService,
+  ) {
+    super(
+      undefined, requestService, rdbService, objectCache, halService, undefined,
+      // interpolate id/uuid as query parameter
+      (endpoint: string, resourceID: string): string => {
+        return endpoint.replace(/{\?id}/, `?id=${resourceID}`)
+                       .replace(/{\?uuid}/, `?uuid=${resourceID}`);
+      },
+    );
+  }
+
+  /**
+   * The default 'pid' endpoint for identifiers does not support uuid lookups.
+   * For uuid lookups we need to change the linkPath.
+   * @param identifierType
+   */
+  setLinkPath(identifierType: IdentifierType) {
+    if (identifierType === IdentifierType.UUID) {
+      this.linkPath = UUID_ENDPOINT;
+    } else {
+      this.linkPath = ID_ENDPOINT;
+    }
+  }
+}
+
+/**
+ * A service to handle redirects from identifier paths to DSO path
+ * e.g.: redirect from /handle/... to /items/...
+ */
+@Injectable()
+export class DsoRedirectService {
+  private dataService: DsoByIdOrUUIDDataService;
+
+  constructor(
+    protected requestService: RequestService,
+    protected rdbService: RemoteDataBuildService,
+    protected objectCache: ObjectCacheService,
+    protected halService: HALEndpointService,
+    private router: Router,
+  ) {
+    this.dataService = new DsoByIdOrUUIDDataService(requestService, rdbService, objectCache, halService);
+  }
+
+  /**
+   * Retrieve a DSpaceObject by
+   * @param id              the identifier of the object to retrieve
+   * @param identifierType  the type of the given identifier (defaults to UUID)
+   */
+  findByIdAndIDType(id: string, identifierType = IdentifierType.UUID): Observable<RemoteData<DSpaceObject>> {
+    this.dataService.setLinkPath(identifierType);
+    return this.dataService.findById(id).pipe(
+      getFirstCompletedRemoteData(),
+      tap((response) => {
+        if (response.hasSucceeded) {
+          const dso = response.payload;
+          if (hasValue(dso.uuid)) {
+            let newRoute = getDSORoute(dso);
+            if (hasValue(newRoute)) {
+              this.router.navigate([newRoute]);
+            }
+          }
+        }
+      })
+    );
+  }
+}

src/app/core/data/dspace-object-data.service.spec.ts

@@ -7,8 +7,6 @@ import { GetRequest } from './request.models';
 import { RequestService } from './request.service';
 import { DSpaceObjectDataService } from './dspace-object-data.service';
 import { ObjectCacheService } from '../cache/object-cache.service';
-import { NotificationsService } from '../../shared/notifications/notifications.service';
-import { HttpClient } from '@angular/common/http';
 
 describe('DSpaceObjectDataService', () => {
   let scheduler: TestScheduler;
@@ -42,18 +40,12 @@ describe('DSpaceObjectDataService', () => {
       })
     });
     objectCache = {} as ObjectCacheService;
-    const notificationsService = {} as NotificationsService;
-    const http = {} as HttpClient;
-    const comparator = {} as any;
 
     service = new DSpaceObjectDataService(
       requestService,
       rdbService,
       objectCache,
       halService,
-      notificationsService,
-      http,
-      comparator
     );
   });
 

src/app/core/data/dspace-object-data.service.ts

@@ -1,106 +1,28 @@
-/* eslint-disable max-classes-per-file */
-import { HttpClient } from '@angular/common/http';
 import { Injectable } from '@angular/core';
-import { Store } from '@ngrx/store';
-import { Observable } from 'rxjs';
-import { NotificationsService } from '../../shared/notifications/notifications.service';
-import { FollowLinkConfig } from '../../shared/utils/follow-link-config.model';
-import { dataService } from '../cache/builders/build-decorators';
 import { RemoteDataBuildService } from '../cache/builders/remote-data-build.service';
 import { ObjectCacheService } from '../cache/object-cache.service';
 import { DSpaceObject } from '../shared/dspace-object.model';
 import { DSPACE_OBJECT } from '../shared/dspace-object.resource-type';
 import { HALEndpointService } from '../shared/hal-endpoint.service';
-import { DataService } from './data.service';
-import { DSOChangeAnalyzer } from './dso-change-analyzer.service';
-import { RemoteData } from './remote-data';
 import { RequestService } from './request.service';
-import { PaginatedList } from './paginated-list.model';
+import { IdentifiableDataService } from './base/identifiable-data.service';
-import { CoreState } from '../core-state.model';
+import { dataService } from './base/data-service.decorator';
-import { FindListOptions } from './find-list-options.model';
-
-class DataServiceImpl extends DataService<DSpaceObject> {
-  protected linkPath = 'dso';
-
-  constructor(
-    protected requestService: RequestService,
-    protected rdbService: RemoteDataBuildService,
-    protected store: Store<CoreState>,
-    protected objectCache: ObjectCacheService,
-    protected halService: HALEndpointService,
-    protected notificationsService: NotificationsService,
-    protected http: HttpClient,
-    protected comparator: DSOChangeAnalyzer<DSpaceObject>) {
-    super();
-  }
-
-  getIDHref(endpoint, resourceID,  ...linksToFollow: FollowLinkConfig<DSpaceObject>[]): string {
-    return this.buildHrefFromFindOptions( endpoint.replace(/\{\?uuid\}/, `?uuid=${resourceID}`),
-      {}, [], ...linksToFollow);
-  }
-}
 
 @Injectable()
 @dataService(DSPACE_OBJECT)
-export class DSpaceObjectDataService {
+export class DSpaceObjectDataService extends IdentifiableDataService<DSpaceObject> {
-  protected linkPath = 'dso';
-  private dataService: DataServiceImpl;
-
   constructor(
     protected requestService: RequestService,
     protected rdbService: RemoteDataBuildService,
     protected objectCache: ObjectCacheService,
     protected halService: HALEndpointService,
-    protected notificationsService: NotificationsService,
+  ) {
-    protected http: HttpClient,
+    super(
-    protected comparator: DSOChangeAnalyzer<DSpaceObject>) {
+      'dso', requestService, rdbService, objectCache, halService, undefined,
-    this.dataService = new DataServiceImpl(requestService, rdbService, null, objectCache, halService, notificationsService, http, comparator);
+      // interpolate uuid as query parameter
+      (endpoint: string, resourceID: string): string => {
+        return endpoint.replace(/{\?uuid}/, `?uuid=${resourceID}`);
+      },
+    );
   }
-
-  /**
-   * Returns an observable of {@link RemoteData} of an object, based on its ID, with a list of {@link FollowLinkConfig},
-   * to automatically resolve {@link HALLink}s of the object
-   * @param id                ID of object we want to retrieve
-   * @param useCachedVersionIfAvailable If this is true, the request will only be sent if there's
-   *                                    no valid cached version. Defaults to true
-   * @param reRequestOnStale            Whether or not the request should automatically be re-
-   *                                    requested after the response becomes stale
-   * @param linksToFollow               List of {@link FollowLinkConfig} that indicate which
-   *                                    {@link HALLink}s should be automatically resolved
-   */
-  findById(id: string, useCachedVersionIfAvailable = true, reRequestOnStale = true, ...linksToFollow: FollowLinkConfig<DSpaceObject>[]): Observable<RemoteData<DSpaceObject>> {
-    return this.dataService.findById(id, useCachedVersionIfAvailable, reRequestOnStale, ...linksToFollow);
-
-  }
-  /**
-   * Returns an observable of {@link RemoteData} of an object, based on an href, with a list of {@link FollowLinkConfig},
-   * to automatically resolve {@link HALLink}s of the object
-   * @param href                        The url of object we want to retrieve
-   * @param useCachedVersionIfAvailable If this is true, the request will only be sent if there's
-   *                                    no valid cached version. Defaults to true
-   * @param reRequestOnStale            Whether or not the request should automatically be re-
-   *                                    requested after the response becomes stale
-   * @param linksToFollow               List of {@link FollowLinkConfig} that indicate which
-   *                                    {@link HALLink}s should be automatically resolved
-   */
-  findByHref(href: string, useCachedVersionIfAvailable = true, reRequestOnStale = true, ...linksToFollow: FollowLinkConfig<DSpaceObject>[]): Observable<RemoteData<DSpaceObject>> {
-    return this.dataService.findByHref(href, useCachedVersionIfAvailable, reRequestOnStale, ...linksToFollow);
-  }
-
-  /**
-   * Returns a list of observables of {@link RemoteData} of objects, based on an href, with a list of {@link FollowLinkConfig},
-   * to automatically resolve {@link HALLink}s of the object
-   * @param href                        The url of object we want to retrieve
-   * @param findListOptions             Find list options object
-   * @param useCachedVersionIfAvailable If this is true, the request will only be sent if there's
-   *                                    no valid cached version. Defaults to true
-   * @param reRequestOnStale            Whether or not the request should automatically be re-
-   *                                    requested after the response becomes stale
-   * @param linksToFollow               List of {@link FollowLinkConfig} that indicate which
-   *                                    {@link HALLink}s should be automatically resolved
-   */
-  findAllByHref(href: string, findListOptions: FindListOptions = {}, useCachedVersionIfAvailable = true, reRequestOnStale = true, ...linksToFollow: FollowLinkConfig<DSpaceObject>[]): Observable<RemoteData<PaginatedList<DSpaceObject>>> {
-    return this.dataService.findAllByHref(href, findListOptions, useCachedVersionIfAvailable, reRequestOnStale, ...linksToFollow);
-  }
-
 }

src/app/core/data/entity-type-data.service.spec.ts

@@ -0,0 +1,19 @@
+/**
+ * The contents of this file are subject to the license and copyright
+ * detailed in the LICENSE and NOTICE files at the root of the source
+ * tree and available online at
+ *
+ * http://www.dspace.org/license/
+ */
+
+import { testFindAllDataImplementation } from './base/find-all-data.spec';
+import { testSearchDataImplementation } from './base/search-data.spec';
+import { EntityTypeDataService } from './entity-type-data.service';
+
+describe('EntityTypeDataService', () => {
+  describe('composition', () => {
+    const initService = () => new EntityTypeDataService(null, null, null, null, null);
+    testFindAllDataImplementation(initService);
+    testSearchDataImplementation(initService);
+  });
+});

src/app/core/data/entity-type-data.service.ts

@@ -1,13 +1,8 @@
 import { FollowLinkConfig } from '../../shared/utils/follow-link-config.model';
-import { DataService } from './data.service';
 import { RequestService } from './request.service';
 import { RemoteDataBuildService } from '../cache/builders/remote-data-build.service';
-import { Store } from '@ngrx/store';
 import { HALEndpointService } from '../shared/hal-endpoint.service';
 import { ObjectCacheService } from '../cache/object-cache.service';
-import { NotificationsService } from '../../shared/notifications/notifications.service';
-import { HttpClient } from '@angular/common/http';
-import { DefaultChangeAnalyzer } from './default-change-analyzer.service';
 import { Injectable } from '@angular/core';
 import { Observable } from 'rxjs';
 import { filter, map, switchMap, take } from 'rxjs/operators';
@@ -16,28 +11,31 @@ import { RelationshipType } from '../shared/item-relationships/relationship-type
 import { PaginatedList } from './paginated-list.model';
 import { ItemType } from '../shared/item-relationships/item-type.model';
 import { getFirstSucceededRemoteData, getRemoteDataPayload } from '../shared/operators';
-import { RelationshipTypeService } from './relationship-type.service';
+import { RelationshipTypeDataService } from './relationship-type-data.service';
-import { CoreState } from '../core-state.model';
 import { FindListOptions } from './find-list-options.model';
+import { BaseDataService } from './base/base-data.service';
+import { SearchData, SearchDataImpl } from './base/search-data';
+import { FindAllData, FindAllDataImpl } from './base/find-all-data';
 
 /**
  * Service handling all ItemType requests
  */
 @Injectable()
-export class EntityTypeService extends DataService<ItemType> {
+export class EntityTypeDataService extends BaseDataService<ItemType> implements FindAllData<ItemType>, SearchData<ItemType> {
+  private findAllData: FindAllData<ItemType>;
+  private searchData: SearchDataImpl<ItemType>;
 
-  protected linkPath = 'entitytypes';
+  constructor(
-
+    protected requestService: RequestService,
-  constructor(protected requestService: RequestService,
     protected rdbService: RemoteDataBuildService,
-              protected store: Store<CoreState>,
-              protected halService: HALEndpointService,
     protected objectCache: ObjectCacheService,
-              protected notificationsService: NotificationsService,
+    protected halService: HALEndpointService,
-              protected relationshipTypeService: RelationshipTypeService,
+    protected relationshipTypeService: RelationshipTypeDataService,
-              protected http: HttpClient,
+  ) {
-              protected comparator: DefaultChangeAnalyzer<ItemType>) {
+    super('entitytypes', requestService, rdbService, objectCache, halService);
-    super();
+
+    this.findAllData = new FindAllDataImpl(this.linkPath, requestService, rdbService, objectCache, halService, this.responseMsToLive);
+    this.searchData = new SearchDataImpl(this.linkPath, requestService, rdbService, objectCache, halService, this.responseMsToLive);
   }
 
   getBrowseEndpoint(options, linkPath?: string): Observable<string> {
@@ -147,7 +145,7 @@ export class EntityTypeService extends DataService<ItemType> {
    */
   getEntityTypeRelationships(entityTypeId: string, useCachedVersionIfAvailable = true, reRequestOnStale = true, ...linksToFollow: FollowLinkConfig<RelationshipType>[]): Observable<RemoteData<PaginatedList<RelationshipType>>> {
     const href$ = this.getRelationshipTypesEndpoint(entityTypeId);
-    return this.relationshipTypeService.findAllByHref(href$, undefined, useCachedVersionIfAvailable, reRequestOnStale, ...linksToFollow);
+    return this.relationshipTypeService.findListByHref(href$, undefined, useCachedVersionIfAvailable, reRequestOnStale, ...linksToFollow);
   }
 
   /**
@@ -158,7 +156,43 @@ export class EntityTypeService extends DataService<ItemType> {
     return this.halService.getEndpoint(this.linkPath).pipe(
       take(1),
       switchMap((endPoint: string) =>
-        this.findByHref(endPoint + '/label/' + label))
+        this.findByHref(endPoint + '/label/' + label)),
     );
   }
+
+  /**
+   * Returns {@link RemoteData} of all object with a list of {@link FollowLinkConfig}, to indicate which embedded
+   * info should be added to the objects
+   *
+   * @param options                     Find list options object
+   * @param useCachedVersionIfAvailable If this is true, the request will only be sent if there's
+   *                                    no valid cached version. Defaults to true
+   * @param reRequestOnStale            Whether or not the request should automatically be re-
+   *                                    requested after the response becomes stale
+   * @param linksToFollow               List of {@link FollowLinkConfig} that indicate which
+   *                                    {@link HALLink}s should be automatically resolved
+   * @return {Observable<RemoteData<PaginatedList<T>>>}
+   *    Return an observable that emits object list
+   */
+  public findAll(options?: FindListOptions, useCachedVersionIfAvailable?: boolean, reRequestOnStale?: boolean, ...linksToFollow: FollowLinkConfig<ItemType>[]): Observable<RemoteData<PaginatedList<ItemType>>> {
+    return this.findAllData.findAll(options, useCachedVersionIfAvailable, reRequestOnStale, ...linksToFollow);
+  }
+
+  /**
+   * Make a new FindListRequest with given search method
+   *
+   * @param searchMethod                The search method for the object
+   * @param options                     The [[FindListOptions]] object
+   * @param useCachedVersionIfAvailable If this is true, the request will only be sent if there's
+   *                                    no valid cached version. Defaults to true
+   * @param reRequestOnStale            Whether or not the request should automatically be re-
+   *                                    requested after the response becomes stale
+   * @param linksToFollow               List of {@link FollowLinkConfig} that indicate which
+   *                                    {@link HALLink}s should be automatically resolved
+   * @return {Observable<RemoteData<PaginatedList<T>>}
+   *    Return an observable that emits response from the server
+   */
+  searchBy(searchMethod: string, options?: FindListOptions, useCachedVersionIfAvailable?: boolean, reRequestOnStale?: boolean, ...linksToFollow: FollowLinkConfig<ItemType>[]): Observable<RemoteData<PaginatedList<ItemType>>> {
+    return this.searchData.searchBy(searchMethod, options, useCachedVersionIfAvailable, reRequestOnStale, ...linksToFollow);
+  }
 }

src/app/core/data/eperson-registration.service.ts

@@ -13,11 +13,9 @@ import { RegistrationResponseParsingService } from './registration-response-pars
 import { RemoteData } from './remote-data';
 import { RemoteDataBuildService } from '../cache/builders/remote-data-build.service';
 
-@Injectable(
+@Injectable({
-  {
   providedIn: 'root',
-  }
+})
-)
 /**
  * Service that will register a new email address and request a token
  */

src/app/core/data/external-source-data.service.spec.ts

@@ -1,12 +1,13 @@
-import { ExternalSourceService } from './external-source.service';
+import { ExternalSourceDataService } from './external-source-data.service';
 import { createSuccessfulRemoteDataObject$ } from '../../shared/remote-data.utils';
 import { createPaginatedList } from '../../shared/testing/utils.test';
 import { ExternalSourceEntry } from '../shared/external-source-entry.model';
 import { of as observableOf } from 'rxjs';
 import { GetRequest } from './request.models';
+import { testSearchDataImplementation } from './base/search-data.spec';
 
 describe('ExternalSourceService', () => {
-  let service: ExternalSourceService;
+  let service: ExternalSourceDataService;
 
   let requestService;
   let rdbService;
@@ -48,15 +49,20 @@ describe('ExternalSourceService', () => {
       buildList: createSuccessfulRemoteDataObject$(createPaginatedList(entries))
     });
     halService = jasmine.createSpyObj('halService', {
-      getEndpoint: observableOf('external-sources-REST-endpoint')
+      getEndpoint: observableOf('external-sources-REST-endpoint'),
     });
-    service = new ExternalSourceService(requestService, rdbService, undefined, undefined, halService, undefined, undefined, undefined);
+    service = new ExternalSourceDataService(requestService, rdbService, undefined, halService);
   }
 
   beforeEach(() => {
     init();
   });
 
+  describe('composition', () => {
+    const initService = () => new ExternalSourceDataService(null, null, null, null);
+    testSearchDataImplementation(initService);
+  });
+
   describe('getExternalSourceEntries', () => {
     let result;
 

src/app/core/data/external-source-data.service.ts

@@ -1,13 +1,9 @@
 import { Injectable } from '@angular/core';
-import { DataService } from './data.service';
 import { ExternalSource } from '../shared/external-source.model';
 import { RequestService } from './request.service';
 import { RemoteDataBuildService } from '../cache/builders/remote-data-build.service';
-import { Store } from '@ngrx/store';
 import { ObjectCacheService } from '../cache/object-cache.service';
 import { HALEndpointService } from '../shared/hal-endpoint.service';
-import { NotificationsService } from '../../shared/notifications/notifications.service';
-import { HttpClient } from '@angular/common/http';
 import { Observable } from 'rxjs';
 import { distinctUntilChanged, map, switchMap, take } from 'rxjs/operators';
 import { PaginatedSearchOptions } from '../../shared/search/models/paginated-search-options.model';
@@ -15,28 +11,27 @@ import { hasValue, isNotEmptyOperator } from '../../shared/empty.util';
 import { RemoteData } from './remote-data';
 import { PaginatedList } from './paginated-list.model';
 import { ExternalSourceEntry } from '../shared/external-source-entry.model';
-import { DefaultChangeAnalyzer } from './default-change-analyzer.service';
 import { FollowLinkConfig } from '../../shared/utils/follow-link-config.model';
-import { CoreState } from '../core-state.model';
 import { FindListOptions } from './find-list-options.model';
+import { IdentifiableDataService } from './base/identifiable-data.service';
+import { SearchData, SearchDataImpl } from './base/search-data';
 
 /**
  * A service handling all external source requests
  */
 @Injectable()
-export class ExternalSourceService extends DataService<ExternalSource> {
+export class ExternalSourceDataService extends IdentifiableDataService<ExternalSource> implements SearchData<ExternalSource> {
-  protected linkPath = 'externalsources';
+  private searchData: SearchData<ExternalSource>;
 
   constructor(
     protected requestService: RequestService,
     protected rdbService: RemoteDataBuildService,
-    protected store: Store<CoreState>,
     protected objectCache: ObjectCacheService,
     protected halService: HALEndpointService,
-    protected notificationsService: NotificationsService,
+  ) {
-    protected http: HttpClient,
+    super('externalsources', requestService, rdbService, objectCache, halService);
-    protected comparator: DefaultChangeAnalyzer<ExternalSource>) {
+
-    super();
+    this.searchData = new SearchDataImpl(this.linkPath, requestService, rdbService, objectCache, halService, this.responseMsToLive);
   }
 
   /**
@@ -75,10 +70,28 @@ export class ExternalSourceService extends DataService<ExternalSource> {
       isNotEmptyOperator(),
       distinctUntilChanged(),
       map((endpoint: string) => hasValue(searchOptions) ? searchOptions.toRestUrl(endpoint) : endpoint),
-      take(1)
+      take(1),
     );
 
     // TODO create a dedicated ExternalSourceEntryDataService and move this entire method to it. Then the "as any"s won't be necessary
-    return this.findAllByHref(href$, undefined, useCachedVersionIfAvailable, reRequestOnStale, ...linksToFollow as any) as any;
+    return this.findListByHref(href$, undefined, useCachedVersionIfAvailable, reRequestOnStale, ...linksToFollow as any) as any;
+  }
+
+  /**
+   * Make a new FindListRequest with given search method
+   *
+   * @param searchMethod                The search method for the object
+   * @param options                     The [[FindListOptions]] object
+   * @param useCachedVersionIfAvailable If this is true, the request will only be sent if there's
+   *                                    no valid cached version. Defaults to true
+   * @param reRequestOnStale            Whether or not the request should automatically be re-
+   *                                    requested after the response becomes stale
+   * @param linksToFollow               List of {@link FollowLinkConfig} that indicate which
+   *                                    {@link HALLink}s should be automatically resolved
+   * @return {Observable<RemoteData<PaginatedList<T>>}
+   *    Return an observable that emits response from the server
+   */
+  public searchBy(searchMethod: string, options?: FindListOptions, useCachedVersionIfAvailable?: boolean, reRequestOnStale?: boolean, ...linksToFollow: FollowLinkConfig<ExternalSource>[]): Observable<RemoteData<PaginatedList<ExternalSource>>> {
+    return this.searchData.searchBy(searchMethod, options, useCachedVersionIfAvailable, reRequestOnStale, ...linksToFollow);
   }
 }

src/app/core/data/feature-authorization/authorization-data.service.spec.ts

@@ -1,6 +1,5 @@
 import { AuthorizationDataService } from './authorization-data.service';
 import { SiteDataService } from '../site-data.service';
-import { AuthService } from '../../auth/auth.service';
 import { Site } from '../../shared/site.model';
 import { EPerson } from '../../eperson/models/eperson.model';
 import { of as observableOf } from 'rxjs';
@@ -12,11 +11,11 @@ import { createFailedRemoteDataObject$, createSuccessfulRemoteDataObject$ } from
 import { createPaginatedList } from '../../../shared/testing/utils.test';
 import { Feature } from '../../shared/feature.model';
 import { FindListOptions } from '../find-list-options.model';
+import { testSearchDataImplementation } from '../base/search-data.spec';
 
 describe('AuthorizationDataService', () => {
   let service: AuthorizationDataService;
   let siteService: SiteDataService;
-  let authService: AuthService;
 
   let site: Site;
   let ePerson: EPerson;
@@ -37,13 +36,9 @@ describe('AuthorizationDataService', () => {
       uuid: 'test-eperson'
     });
     siteService = jasmine.createSpyObj('siteService', {
-      find: observableOf(site)
+      find: observableOf(site),
     });
-    authService = {
+    service = new AuthorizationDataService(requestService, undefined, undefined, undefined, siteService);
-      isAuthenticated: () => observableOf(true),
-      getAuthenticatedUserFromStore: () => observableOf(ePerson)
-    } as AuthService;
-    service = new AuthorizationDataService(requestService, undefined, undefined, undefined, undefined, undefined, undefined, undefined, authService, siteService);
   }
 
   beforeEach(() => {
@@ -51,6 +46,11 @@ describe('AuthorizationDataService', () => {
     spyOn(service, 'searchBy').and.returnValue(observableOf(undefined));
   });
 
+  describe('composition', () => {
+    const initService = () => new AuthorizationDataService(null, null, null, null, null);
+    testSearchDataImplementation(initService);
+  });
+
   it('should call setStaleByHrefSubstring method', () => {
     service.invalidateAuthorizationsRequestCache();
     expect((service as any).requestService.setStaleByHrefSubstring).toHaveBeenCalledWith((service as any).linkPath);

src/app/core/data/feature-authorization/authorization-data.service.ts

@@ -1,18 +1,11 @@
 import { Observable, of as observableOf } from 'rxjs';
 import { Injectable } from '@angular/core';
 import { AUTHORIZATION } from '../../shared/authorization.resource-type';
-import { dataService } from '../../cache/builders/build-decorators';
-import { DataService } from '../data.service';
 import { Authorization } from '../../shared/authorization.model';
 import { RequestService } from '../request.service';
 import { RemoteDataBuildService } from '../../cache/builders/remote-data-build.service';
-import { Store } from '@ngrx/store';
 import { ObjectCacheService } from '../../cache/object-cache.service';
 import { HALEndpointService } from '../../shared/hal-endpoint.service';
-import { NotificationsService } from '../../../shared/notifications/notifications.service';
-import { HttpClient } from '@angular/common/http';
-import { DSOChangeAnalyzer } from '../dso-change-analyzer.service';
-import { AuthService } from '../../auth/auth.service';
 import { SiteDataService } from '../site-data.service';
 import { followLink, FollowLinkConfig } from '../../../shared/utils/follow-link-config.model';
 import { RemoteData } from '../remote-data';
@@ -24,31 +17,32 @@ import { AuthorizationSearchParams } from './authorization-search-params';
 import { addSiteObjectUrlIfEmpty, oneAuthorizationMatchesFeature } from './authorization-utils';
 import { FeatureID } from './feature-id';
 import { getFirstCompletedRemoteData } from '../../shared/operators';
-import { CoreState } from '../../core-state.model';
 import { FindListOptions } from '../find-list-options.model';
+import { BaseDataService } from '../base/base-data.service';
+import { SearchData, SearchDataImpl } from '../base/search-data';
+import { dataService } from '../base/data-service.decorator';
 
 /**
  * A service to retrieve {@link Authorization}s from the REST API
  */
 @Injectable()
 @dataService(AUTHORIZATION)
-export class AuthorizationDataService extends DataService<Authorization> {
+export class AuthorizationDataService extends BaseDataService<Authorization> implements SearchData<Authorization> {
   protected linkPath = 'authorizations';
   protected searchByObjectPath = 'object';
 
+  private searchData: SearchDataImpl<Authorization>;
+
   constructor(
     protected requestService: RequestService,
     protected rdbService: RemoteDataBuildService,
-    protected store: Store<CoreState>,
     protected objectCache: ObjectCacheService,
     protected halService: HALEndpointService,
-    protected notificationsService: NotificationsService,
+    protected siteService: SiteDataService,
-    protected http: HttpClient,
-    protected comparator: DSOChangeAnalyzer<Authorization>,
-    protected authService: AuthService,
-    protected siteService: SiteDataService
   ) {
-    super();
+    super('authorizations', requestService, rdbService, objectCache, halService);
+
+    this.searchData = new SearchDataImpl(this.linkPath, requestService, rdbService, objectCache, halService, this.responseMsToLive);
   }
 
   /**
@@ -130,7 +124,25 @@ export class AuthorizationDataService extends DataService<Authorization> {
       params.push(new RequestParam('eperson', ePersonUuid));
     }
     return Object.assign(new FindListOptions(), options, {
-      searchParams: [...params]
+      searchParams: [...params],
     });
   }
+
+  /**
+   * Make a new FindListRequest with given search method
+   *
+   * @param searchMethod                The search method for the object
+   * @param options                     The [[FindListOptions]] object
+   * @param useCachedVersionIfAvailable If this is true, the request will only be sent if there's
+   *                                    no valid cached version. Defaults to true
+   * @param reRequestOnStale            Whether or not the request should automatically be re-
+   *                                    requested after the response becomes stale
+   * @param linksToFollow               List of {@link FollowLinkConfig} that indicate which
+   *                                    {@link HALLink}s should be automatically resolved
+   * @return {Observable<RemoteData<PaginatedList<T>>}
+   *    Return an observable that emits response from the server
+   */
+  searchBy(searchMethod: string, options?: FindListOptions, useCachedVersionIfAvailable?: boolean, reRequestOnStale?: boolean, ...linksToFollow: FollowLinkConfig<Authorization>[]): Observable<RemoteData<PaginatedList<Authorization>>> {
+    return this.searchData.searchBy(searchMethod, options, useCachedVersionIfAvailable, reRequestOnStale, ...linksToFollow);
+  }
 }

src/app/core/data/feature-authorization/feature-data.service.ts

@@ -1,36 +1,27 @@
 import { Injectable } from '@angular/core';
 import { FEATURE } from '../../shared/feature.resource-type';
-import { dataService } from '../../cache/builders/build-decorators';
-import { DataService } from '../data.service';
 import { Feature } from '../../shared/feature.model';
 import { RequestService } from '../request.service';
 import { RemoteDataBuildService } from '../../cache/builders/remote-data-build.service';
-import { Store } from '@ngrx/store';
 import { ObjectCacheService } from '../../cache/object-cache.service';
 import { HALEndpointService } from '../../shared/hal-endpoint.service';
-import { NotificationsService } from '../../../shared/notifications/notifications.service';
+import { BaseDataService } from '../base/base-data.service';
-import { HttpClient } from '@angular/common/http';
+import { dataService } from '../base/data-service.decorator';
-import { DSOChangeAnalyzer } from '../dso-change-analyzer.service';
-import { CoreState } from '../../core-state.model';
 
 /**
  * A service to retrieve {@link Feature}s from the REST API
  */
 @Injectable()
 @dataService(FEATURE)
-export class FeatureDataService extends DataService<Feature> {
+export class FeatureDataService extends BaseDataService<Feature> {
   protected linkPath = 'features';
 
   constructor(
     protected requestService: RequestService,
     protected rdbService: RemoteDataBuildService,
-    protected store: Store<CoreState>,
     protected objectCache: ObjectCacheService,
     protected halService: HALEndpointService,
-    protected notificationsService: NotificationsService,
-    protected http: HttpClient,
-    protected comparator: DSOChangeAnalyzer<Feature>
   ) {
-    super();
+    super('features', requestService, rdbService, objectCache, halService);
   }
 }

src/app/core/data/href-only-data.service.spec.ts

@@ -1,8 +1,8 @@
 import { HrefOnlyDataService } from './href-only-data.service';
 import { followLink, FollowLinkConfig } from '../../shared/utils/follow-link-config.model';
 import { createSuccessfulRemoteDataObject$ } from '../../shared/remote-data.utils';
-import { DataService } from './data.service';
 import { FindListOptions } from './find-list-options.model';
+import { BaseDataService } from './base/base-data.service';
 
 describe(`HrefOnlyDataService`, () => {
   let service: HrefOnlyDataService;
@@ -15,12 +15,12 @@ describe(`HrefOnlyDataService`, () => {
     href = 'https://rest.api/server/api/core/items/de7fa215-4a25-43a7-a4d7-17534a09fdfc';
     followLinks = [ followLink('link1'), followLink('link2') ];
     findListOptions = new FindListOptions();
-    service = new HrefOnlyDataService(null, null, null, null, null, null, null, null);
+    service = new HrefOnlyDataService(null, null, null, null);
   });
 
   it(`should instantiate a private DataService`, () => {
     expect((service as any).dataService).toBeDefined();
-    expect((service as any).dataService).toBeInstanceOf(DataService);
+    expect((service as any).dataService).toBeInstanceOf(BaseDataService);
   });
 
     describe(`findByHref`, () => {
@@ -28,7 +28,7 @@ describe(`HrefOnlyDataService`, () => {
         spy = spyOn((service as any).dataService, 'findByHref').and.returnValue(createSuccessfulRemoteDataObject$(null));
       });
 
-      it(`should delegate to findByHref on the internal DataService`, () => {
+      it(`should forward to findByHref on the internal DataService`, () => {
         service.findByHref(href, false, false, ...followLinks);
         expect(spy).toHaveBeenCalledWith(href, false, false, ...followLinks);
       });
@@ -48,33 +48,33 @@ describe(`HrefOnlyDataService`, () => {
       });
     });
 
-    describe(`findAllByHref`, () => {
+    describe(`findListByHref`, () => {
       beforeEach(() => {
-        spy = spyOn((service as any).dataService, 'findAllByHref').and.returnValue(createSuccessfulRemoteDataObject$(null));
+        spy = spyOn((service as any).dataService, 'findListByHref').and.returnValue(createSuccessfulRemoteDataObject$(null));
       });
 
-      it(`should delegate to findAllByHref on the internal DataService`, () => {
+      it(`should delegate to findListByHref on the internal DataService`, () => {
-        service.findAllByHref(href, findListOptions, false, false, ...followLinks);
+        service.findListByHref(href, findListOptions, false, false, ...followLinks);
         expect(spy).toHaveBeenCalledWith(href, findListOptions, false, false, ...followLinks);
       });
 
       describe(`when findListOptions is omitted`, () => {
-        it(`should call findAllByHref on the internal DataService with findListOptions = {}`, () => {
+        it(`should call findListByHref on the internal DataService with findListOptions = {}`, () => {
-            service.findAllByHref(href);
+            service.findListByHref(href);
             expect(spy).toHaveBeenCalledWith(jasmine.anything(), {}, jasmine.anything(), jasmine.anything());
         });
       });
 
       describe(`when useCachedVersionIfAvailable is omitted`, () => {
-        it(`should call findAllByHref on the internal DataService with useCachedVersionIfAvailable = true`, () => {
+        it(`should call findListByHref on the internal DataService with useCachedVersionIfAvailable = true`, () => {
-            service.findAllByHref(href);
+            service.findListByHref(href);
             expect(spy).toHaveBeenCalledWith(jasmine.anything(), jasmine.anything(), true, jasmine.anything());
         });
       });
 
       describe(`when reRequestOnStale is omitted`, () => {
-        it(`should call findAllByHref on the internal DataService with reRequestOnStale = true`, () => {
+        it(`should call findListByHref on the internal DataService with reRequestOnStale = true`, () => {
-            service.findAllByHref(href);
+            service.findListByHref(href);
             expect(spy).toHaveBeenCalledWith(jasmine.anything(), jasmine.anything(), jasmine.anything(), true);
         });
       });

src/app/core/data/href-only-data.service.ts

@@ -1,42 +1,20 @@
-/* eslint-disable max-classes-per-file */
-import { DataService } from './data.service';
 import { RequestService } from './request.service';
 import { RemoteDataBuildService } from '../cache/builders/remote-data-build.service';
-import { Store } from '@ngrx/store';
 import { ObjectCacheService } from '../cache/object-cache.service';
 import { HALEndpointService } from '../shared/hal-endpoint.service';
-import { NotificationsService } from '../../shared/notifications/notifications.service';
-import { HttpClient } from '@angular/common/http';
-import { DefaultChangeAnalyzer } from './default-change-analyzer.service';
 import { Injectable } from '@angular/core';
 import { VOCABULARY_ENTRY } from '../submission/vocabularies/models/vocabularies.resource-type';
 import { FollowLinkConfig } from '../../shared/utils/follow-link-config.model';
-import { dataService } from '../cache/builders/build-decorators';
 import { RemoteData } from './remote-data';
 import { Observable } from 'rxjs';
 import { PaginatedList } from './paginated-list.model';
 import { ITEM_TYPE } from '../shared/item-relationships/item-type.resource-type';
 import { LICENSE } from '../shared/license.resource-type';
 import { CacheableObject } from '../cache/cacheable-object.model';
-import { CoreState } from '../core-state.model';
 import { FindListOptions } from './find-list-options.model';
-
+import { BaseDataService } from './base/base-data.service';
-class DataServiceImpl extends DataService<any> {
+import { HALDataService } from './base/hal-data-service.interface';
-  // linkPath isn't used if we're only searching by href.
+import { dataService } from './base/data-service.decorator';
-  protected linkPath = undefined;
-
-  constructor(
-    protected requestService: RequestService,
-    protected rdbService: RemoteDataBuildService,
-    protected store: Store<CoreState>,
-    protected objectCache: ObjectCacheService,
-    protected halService: HALEndpointService,
-    protected notificationsService: NotificationsService,
-    protected http: HttpClient,
-    protected comparator: DefaultChangeAnalyzer<any>) {
-    super();
-  }
-}
 
 /**
  * A DataService with only findByHref methods. Its purpose is to be used for resources that don't
@@ -44,26 +22,37 @@ class DataServiceImpl extends DataService<any> {
  * for their links to be resolved by the LinkService.
  *
  * an @dataService annotation can be added for any number of these resource types
+ *
+ *
+ * Additionally, this service may be used to retrieve objects by `href` regardless of their type
+ * For example
+ * ```
+ * const items$: Observable<RemoteData<PaginatedList<Item>>> = hrefOnlyDataService.findListByHref<Item>(href);
+ * const sites$: Observable<RemoteData<PaginatedList<Site>>> = hrefOnlyDataService.findListByHref<Site>(href);
+ * ```
+ * This means we cannot extend from {@link BaseDataService} directly because the method signatures would not match.
  */
 @Injectable({
-  providedIn: 'root'
+  providedIn: 'root',
 })
 @dataService(VOCABULARY_ENTRY)
 @dataService(ITEM_TYPE)
 @dataService(LICENSE)
-export class HrefOnlyDataService {
+export class HrefOnlyDataService implements HALDataService<any> {
-  private dataService: DataServiceImpl;
+  /**
+   * Works with a {@link BaseDataService} internally, but only exposes two of its methods
+   * with altered signatures to (optionally) constrain the arbitrary return type.
+   * @private
+   */
+  private dataService: BaseDataService<any>;
 
   constructor(
     protected requestService: RequestService,
     protected rdbService: RemoteDataBuildService,
-    protected store: Store<CoreState>,
     protected objectCache: ObjectCacheService,
     protected halService: HALEndpointService,
-    protected notificationsService: NotificationsService,
+  ) {
-    protected http: HttpClient,
+    this.dataService = new BaseDataService(undefined, requestService, rdbService, objectCache, halService);
-    protected comparator: DefaultChangeAnalyzer<any>) {
-    this.dataService = new DataServiceImpl(requestService, rdbService, store, objectCache, halService, notificationsService, http, comparator);
   }
 
   /**
@@ -93,7 +82,7 @@ export class HrefOnlyDataService {
    * @param linksToFollow               List of {@link FollowLinkConfig} that indicate which
    *                                    {@link HALLink}s should be automatically resolved
    */
-  findAllByHref<T extends CacheableObject>(href: string | Observable<string>, findListOptions: FindListOptions = {}, useCachedVersionIfAvailable = true, reRequestOnStale = true, ...linksToFollow: FollowLinkConfig<T>[]): Observable<RemoteData<PaginatedList<T>>> {
+  findListByHref<T extends CacheableObject>(href: string | Observable<string>, findListOptions: FindListOptions = {}, useCachedVersionIfAvailable = true, reRequestOnStale = true, ...linksToFollow: FollowLinkConfig<T>[]): Observable<RemoteData<PaginatedList<T>>> {
-    return this.dataService.findAllByHref(href, findListOptions, useCachedVersionIfAvailable, reRequestOnStale, ...linksToFollow);
+    return this.dataService.findListByHref(href, findListOptions, useCachedVersionIfAvailable, reRequestOnStale, ...linksToFollow);
   }
 }

src/app/core/data/item-data.service.spec.ts

@@ -10,18 +10,21 @@ import { ObjectCacheService } from '../cache/object-cache.service';
 import { RestResponse } from '../cache/response.models';
 import { ExternalSourceEntry } from '../shared/external-source-entry.model';
 import { ItemDataService } from './item-data.service';
-import { DeleteRequest, GetRequest, PostRequest } from './request.models';
+import { DeleteRequest, PostRequest } from './request.models';
 import { RequestService } from './request.service';
 import { getMockRemoteDataBuildService } from '../../shared/mocks/remote-data-build.service.mock';
 import { CoreState } from '../core-state.model';
 import { RequestEntry } from './request-entry.model';
 import { FindListOptions } from './find-list-options.model';
 import { HALEndpointServiceStub } from 'src/app/shared/testing/hal-endpoint-service.stub';
+import { testCreateDataImplementation } from './base/create-data.spec';
+import { testPatchDataImplementation } from './base/patch-data.spec';
+import { testDeleteDataImplementation } from './base/delete-data.spec';
 
 describe('ItemDataService', () => {
   let scheduler: TestScheduler;
   let service: ItemDataService;
-  let bs: BrowseService;
+  let browseService: BrowseService;
   const requestService = Object.assign(getMockRequestService(), {
     generateRequestId(): string {
       return scopeID;
@@ -78,24 +81,29 @@ describe('ItemDataService', () => {
     return new ItemDataService(
       requestService,
       rdbService,
-      store,
-      bs,
       objectCache,
       halEndpointService,
       notificationsService,
-      http,
       comparator,
-      bundleService
+      browseService,
+      bundleService,
     );
   }
 
+  describe('composition', () => {
+    const initService = () => new ItemDataService(null, null, null, null, null, null, null, null);
+    testCreateDataImplementation(initService);
+    testPatchDataImplementation(initService);
+    testDeleteDataImplementation(initService);
+  });
+
   describe('getBrowseEndpoint', () => {
     beforeEach(() => {
       scheduler = getTestScheduler();
     });
 
     it('should return the endpoint to fetch Items within the given scope and starting with the given string', () => {
-      bs = initMockBrowseService(true);
+      browseService = initMockBrowseService(true);
       service = initTestService();
 
       const result = service.getBrowseEndpoint(options);
@@ -106,7 +114,7 @@ describe('ItemDataService', () => {
 
     describe('if the dc.date.issue browse isn\'t configured for items', () => {
       beforeEach(() => {
-        bs = initMockBrowseService(false);
+        browseService = initMockBrowseService(false);
         service = initTestService();
       });
       it('should throw an error', () => {

src/app/core/data/item-data.service.ts

@@ -1,12 +1,18 @@
-import { HttpClient, HttpHeaders } from '@angular/common/http';
+/**
+ * The contents of this file are subject to the license and copyright
+ * detailed in the LICENSE and NOTICE files at the root of the source
+ * tree and available online at
+ *
+ * http://www.dspace.org/license/
+ */
+/* eslint-disable max-classes-per-file */
+import { HttpHeaders } from '@angular/common/http';
 import { Injectable } from '@angular/core';
-import { Store } from '@ngrx/store';
 import { Observable } from 'rxjs';
 import { distinctUntilChanged, filter, find, map, switchMap, take } from 'rxjs/operators';
 import { hasValue, isNotEmpty, isNotEmptyOperator } from '../../shared/empty.util';
 import { NotificationsService } from '../../shared/notifications/notifications.service';
 import { BrowseService } from '../browse/browse.service';
-import { dataService } from '../cache/builders/build-decorators';
 import { RemoteDataBuildService } from '../cache/builders/remote-data-build.service';
 import { ObjectCacheService } from '../cache/object-cache.service';
 import { HttpOptions } from '../dspace-rest/dspace-rest.service';
@@ -16,8 +22,6 @@ import { HALEndpointService } from '../shared/hal-endpoint.service';
 import { Item } from '../shared/item.model';
 import { ITEM } from '../shared/item.resource-type';
 import { URLCombiner } from '../url-combiner/url-combiner';
-
-import { DataService } from './data.service';
 import { DSOChangeAnalyzer } from './dso-change-analyzer.service';
 import { PaginatedList } from './paginated-list.model';
 import { RemoteData } from './remote-data';
@@ -34,27 +38,42 @@ import { ResponseParsingService } from './parsing.service';
 import { StatusCodeOnlyResponseParsingService } from './status-code-only-response-parsing.service';
 import { sendRequest } from '../shared/request.operators';
 import { RestRequest } from './rest-request.model';
-import { CoreState } from '../core-state.model';
 import { FindListOptions } from './find-list-options.model';
+import { ConstructIdEndpoint, IdentifiableDataService } from './base/identifiable-data.service';
+import { PatchData, PatchDataImpl } from './base/patch-data';
+import { DeleteData, DeleteDataImpl } from './base/delete-data';
+import { RestRequestMethod } from './rest-request-method';
+import { CreateData, CreateDataImpl } from './base/create-data';
+import { RequestParam } from '../cache/models/request-param.model';
+import { dataService } from './base/data-service.decorator';
 
-@Injectable()
+/**
-@dataService(ITEM)
+ * An abstract service for CRUD operations on Items
-export class ItemDataService extends DataService<Item> {
+ * Doesn't specify an endpoint because multiple endpoints support Item-like functionality (e.g. items, itemtemplates)
-  protected linkPath = 'items';
+ * Extend this class to implement data services for Items
+ */
+export abstract class BaseItemDataService extends IdentifiableDataService<Item> implements CreateData<Item>, PatchData<Item>, DeleteData<Item> {
+  private createData: CreateData<Item>;
+  private patchData: PatchData<Item>;
+  private deleteData: DeleteData<Item>;
 
-  constructor(
+  protected constructor(
+    protected linkPath,
     protected requestService: RequestService,
     protected rdbService: RemoteDataBuildService,
-    protected store: Store<CoreState>,
-    protected bs: BrowseService,
     protected objectCache: ObjectCacheService,
     protected halService: HALEndpointService,
     protected notificationsService: NotificationsService,
-    protected http: HttpClient,
     protected comparator: DSOChangeAnalyzer<Item>,
-    protected bundleService: BundleDataService
+    protected browseService: BrowseService,
+    protected bundleService: BundleDataService,
+    protected constructIdEndpoint: ConstructIdEndpoint = (endpoint, resourceID) => `${endpoint}/${resourceID}`,
   ) {
-    super();
+    super(linkPath, requestService, rdbService, objectCache, halService, undefined, constructIdEndpoint);
+
+    this.createData = new CreateDataImpl(this.linkPath, requestService, rdbService, objectCache, halService, notificationsService, this.responseMsToLive);
+    this.patchData = new PatchDataImpl<Item>(this.linkPath, requestService, rdbService, objectCache, halService, comparator, this.responseMsToLive, this.constructIdEndpoint);
+    this.deleteData = new DeleteDataImpl(this.linkPath, requestService, rdbService, objectCache, halService, notificationsService, this.responseMsToLive, this.constructIdEndpoint);
   }
 
   /**
@@ -69,10 +88,11 @@ export class ItemDataService extends DataService<Item> {
     if (options.sort && options.sort.field) {
       field = options.sort.field;
     }
-    return this.bs.getBrowseURLFor(field, linkPath).pipe(
+    return this.browseService.getBrowseURLFor(field, linkPath).pipe(
       filter((href: string) => isNotEmpty(href)),
       map((href: string) => new URLCombiner(href, `?scope=${options.scopeID}`).toString()),
-      distinctUntilChanged(),);
+      distinctUntilChanged(),
+    );
   }
 
   /**
@@ -84,7 +104,7 @@ export class ItemDataService extends DataService<Item> {
   public getMappedCollectionsEndpoint(itemId: string, collectionId?: string): Observable<string> {
     return this.halService.getEndpoint(this.linkPath).pipe(
       map((endpoint: string) => this.getIDHref(endpoint, itemId)),
-      map((endpoint: string) => `${endpoint}/mappedCollections${collectionId ? `/${collectionId}` : ''}`)
+      map((endpoint: string) => `${endpoint}/mappedCollections${collectionId ? `/${collectionId}` : ''}`),
     );
   }
 
@@ -219,7 +239,7 @@ export class ItemDataService extends DataService<Item> {
   public getMoveItemEndpoint(itemId: string): Observable<string> {
     return this.halService.getEndpoint(this.linkPath).pipe(
       map((endpoint: string) => this.getIDHref(endpoint, itemId)),
-      map((endpoint: string) => `${endpoint}/owningCollection`)
+      map((endpoint: string) => `${endpoint}/owningCollection`),
     );
   }
 
@@ -299,4 +319,93 @@ export class ItemDataService extends DataService<Item> {
     this.requestService.setStaleByHrefSubstring('item/' + itemUUID);
   }
 
+  /**
+   * Commit current object changes to the server
+   * @param method The RestRequestMethod for which de server sync buffer should be committed
+   */
+  public commitUpdates(method?: RestRequestMethod): void {
+    this.patchData.commitUpdates(method);
+  }
+
+  /**
+   * Send a patch request for a specified object
+   * @param {T} object The object to send a patch request for
+   * @param {Operation[]} operations The patch operations to be performed
+   */
+  public patch(object: Item, operations: Operation[]): Observable<RemoteData<Item>> {
+    return this.patchData.patch(object, operations);
+  }
+
+  /**
+   * Add a new patch to the object cache
+   * The patch is derived from the differences between the given object and its version in the object cache
+   * @param {DSpaceObject} object The given object
+   */
+  public update(object: Item): Observable<RemoteData<Item>> {
+    return this.patchData.update(object);
+  }
+
+  /**
+   * Return a list of operations representing the difference between an object and its latest value in the cache.
+   * @param object  the object to resolve to a list of patch operations
+   */
+  public createPatchFromCache(object: Item): Observable<Operation[]> {
+    return this.patchData.createPatchFromCache(object);
+  }
+
+  /**
+   * Delete an existing object on the server
+   * @param   objectId The id of the object to be removed
+   * @param   copyVirtualMetadata (optional parameter) the identifiers of the relationship types for which the virtual
+   *                            metadata should be saved as real metadata
+   * @return  A RemoteData observable with an empty payload, but still representing the state of the request: statusCode,
+   *          errorMessage, timeCompleted, etc
+   */
+  public delete(objectId: string, copyVirtualMetadata?: string[]): Observable<RemoteData<NoContent>> {
+    return this.deleteData.delete(objectId, copyVirtualMetadata);
+  }
+
+  /**
+   * Delete an existing object on the server
+   * @param   href The self link of the object to be removed
+   * @param   copyVirtualMetadata (optional parameter) the identifiers of the relationship types for which the virtual
+   *                            metadata should be saved as real metadata
+   * @return  A RemoteData observable with an empty payload, but still representing the state of the request: statusCode,
+   *          errorMessage, timeCompleted, etc
+   *          Only emits once all request related to the DSO has been invalidated.
+   */
+  public deleteByHref(href: string, copyVirtualMetadata?: string[]): Observable<RemoteData<NoContent>> {
+    return this.deleteData.deleteByHref(href, copyVirtualMetadata);
+  }
+
+  /**
+   * Create a new object on the server, and store the response in the object cache
+   *
+   * @param object    The object to create
+   * @param params    Array with additional params to combine with query string
+   */
+  public create(object: Item, ...params: RequestParam[]): Observable<RemoteData<Item>> {
+    return this.createData.create(object, ...params);
+  }
+
+}
+
+/**
+ * A service for CRUD operations on Items
+ */
+@Injectable()
+@dataService(ITEM)
+export class ItemDataService extends BaseItemDataService {
+  constructor(
+    protected requestService: RequestService,
+    protected rdbService: RemoteDataBuildService,
+    protected objectCache: ObjectCacheService,
+    protected halService: HALEndpointService,
+    protected notificationsService: NotificationsService,
+    protected comparator: DSOChangeAnalyzer<Item>,
+    protected browseService: BrowseService,
+    protected bundleService: BundleDataService,
+  ) {
+    super('items', requestService, rdbService, objectCache, halService, notificationsService, comparator, browseService, bundleService);
+  }
 }

src/app/core/data/item-request-data.service.spec.ts

@@ -35,7 +35,7 @@ describe('ItemRequestDataService', () => {
       getEndpoint: observableOf(restApiEndpoint),
     });
 
-    service = new ItemRequestDataService(requestService, rdbService, null, null, halService, null, null, null);
+    service = new ItemRequestDataService(requestService, rdbService, null, halService);
   });
 
   describe('requestACopy', () => {

src/app/core/data/item-request-data.service.ts

@@ -9,40 +9,27 @@ import { PostRequest, PutRequest } from './request.models';
 import { RequestService } from './request.service';
 import { ItemRequest } from '../shared/item-request.model';
 import { hasValue, isNotEmpty } from '../../shared/empty.util';
-import { DataService } from './data.service';
-import { Store } from '@ngrx/store';
 import { ObjectCacheService } from '../cache/object-cache.service';
-import { NotificationsService } from '../../shared/notifications/notifications.service';
+import { HttpHeaders } from '@angular/common/http';
-import { HttpClient, HttpHeaders } from '@angular/common/http';
-import { DefaultChangeAnalyzer } from './default-change-analyzer.service';
 import { RequestCopyEmail } from '../../request-copy/email-request-copy/request-copy-email.model';
 import { HttpOptions } from '../dspace-rest/dspace-rest.service';
-import { CoreState } from '../core-state.model';
 import { sendRequest } from '../shared/request.operators';
+import { IdentifiableDataService } from './base/identifiable-data.service';
 
 /**
  * A service responsible for fetching/sending data from/to the REST API on the itemrequests endpoint
  */
-@Injectable(
+@Injectable({
-  {
   providedIn: 'root',
-  }
+})
-)
+export class ItemRequestDataService extends IdentifiableDataService<ItemRequest> {
-export class ItemRequestDataService extends DataService<ItemRequest> {
-
-  protected linkPath = 'itemrequests';
-
   constructor(
     protected requestService: RequestService,
     protected rdbService: RemoteDataBuildService,
-    protected store: Store<CoreState>,
     protected objectCache: ObjectCacheService,
     protected halService: HALEndpointService,
-    protected notificationsService: NotificationsService,
-    protected http: HttpClient,
-    protected comparator: DefaultChangeAnalyzer<ItemRequest>,
   ) {
-    super();
+    super('itemrequests', requestService, rdbService, objectCache, halService);
   }
 
   getItemRequestEndpoint(): Observable<string> {
@@ -124,9 +111,9 @@ export class ItemRequestDataService extends DataService<ItemRequest> {
           suggestOpenAccess,
         }), options);
       }),
-      sendRequest(this.requestService)).subscribe();
+      sendRequest(this.requestService),
+    ).subscribe();
 
     return this.rdbService.buildFromRequestUUID(requestId);
   }
-
 }

src/app/core/data/item-template-data.service.spec.ts

@@ -8,17 +8,20 @@ import { BrowseService } from '../browse/browse.service';
 import { cold } from 'jasmine-marbles';
 import { HALEndpointService } from '../shared/hal-endpoint.service';
 import { NotificationsService } from '../../shared/notifications/notifications.service';
-import { HttpClient } from '@angular/common/http';
 import { CollectionDataService } from './collection-data.service';
 import { RestRequestMethod } from './rest-request-method';
 import { Item } from '../shared/item.model';
 import { RestRequest } from './rest-request.model';
 import { CoreState } from '../core-state.model';
 import { RequestEntry } from './request-entry.model';
+import { testCreateDataImplementation } from './base/create-data.spec';
+import { testPatchDataImplementation } from './base/patch-data.spec';
+import { testDeleteDataImplementation } from './base/delete-data.spec';
+import createSpyObj = jasmine.createSpyObj;
 
 describe('ItemTemplateDataService', () => {
   let service: ItemTemplateDataService;
-  let itemService: any;
+  let byCollection: any;
 
   const item = new Item();
   const collectionEndpoint = 'https://rest.api/core/collections/4af28e99-6a9c-4036-a199-e1b587046d39';
@@ -47,14 +50,14 @@ describe('ItemTemplateDataService', () => {
   } as RequestService;
   const rdbService = {} as RemoteDataBuildService;
   const store = {} as Store<CoreState>;
-  const bs = {} as BrowseService;
+  const browseService = {} as BrowseService;
   const objectCache = {
     getObjectBySelfLink(self) {
       return observableOf({});
     },
     addPatch(self, operations) {
       // Do nothing
-    }
+    },
   } as any;
   const halEndpointService = {
     getEndpoint(linkPath: string): Observable<string> {
@@ -62,7 +65,6 @@ describe('ItemTemplateDataService', () => {
     }
   } as HALEndpointService;
   const notificationsService = {} as NotificationsService;
-  const http = {} as HttpClient;
   const comparator = {
     diff(first, second) {
       return [{}];
@@ -78,60 +80,68 @@ describe('ItemTemplateDataService', () => {
     service = new ItemTemplateDataService(
       requestService,
       rdbService,
-      store,
-      bs,
       objectCache,
       halEndpointService,
       notificationsService,
-      http,
       comparator,
+      browseService,
       undefined,
-      collectionService
+      collectionService,
     );
-    itemService = (service as any).dataService;
+    byCollection = (service as any).byCollection;
   }
 
   beforeEach(() => {
     initTestService();
   });
 
-  describe('commitUpdates', () => {
+  describe('composition', () => {
-    it('should call commitUpdates on the item service implementation', () => {
+    const initService = () => new ItemTemplateDataService(null, null, null, null, null, null, null, null, null);
-      spyOn(itemService, 'commitUpdates');
+    testCreateDataImplementation(initService);
-      service.commitUpdates();
+    testPatchDataImplementation(initService);
-      expect(itemService.commitUpdates).toHaveBeenCalled();
+    testDeleteDataImplementation(initService);
-    });
-  });
-
-  describe('update', () => {
-    it('should call update on the item service implementation', () => {
-      spyOn(itemService, 'update');
-      service.update(item);
-      expect(itemService.update).toHaveBeenCalled();
-    });
   });
 
   describe('findByCollectionID', () => {
-    it('should call findByCollectionID on the item service implementation', () => {
+    it('should call findByCollectionID on the collection-based data service', () => {
-      spyOn(itemService, 'findByCollectionID');
+      spyOn(byCollection, 'findById');
       service.findByCollectionID(scopeID);
-      expect(itemService.findByCollectionID).toHaveBeenCalled();
+      expect(byCollection.findById).toHaveBeenCalled();
     });
   });
 
-  describe('create', () => {
+  describe('createByCollectionID', () => {
-    it('should call createTemplate on the item service implementation', () => {
+    it('should call createTemplate on the collection-based data service', () => {
-      spyOn(itemService, 'createTemplate');
+      spyOn(byCollection, 'createTemplate');
-      service.create(item, scopeID);
+      service.createByCollectionID(item, scopeID);
-      expect(itemService.createTemplate).toHaveBeenCalled();
+      expect(byCollection.createTemplate).toHaveBeenCalledWith(item, scopeID);
     });
   });
 
-  describe('deleteByCollectionID', () => {
+  describe('byCollection', () => {
-    it('should call deleteByCollectionID on the item service implementation', () => {
+    beforeEach(() => {
-      spyOn(itemService, 'deleteByCollectionID');
+      byCollection.createData = createSpyObj('createData', {
-      service.deleteByCollectionID(item, scopeID);
+        createOnEndpoint: 'TEST createOnEndpoint',
-      expect(itemService.deleteByCollectionID).toHaveBeenCalled();
+      });
+    });
+
+    describe('getIDHrefObs', () => {
+      it('should point to the Item template of a given Collection', () => {
+        expect(byCollection.getIDHrefObs(scopeID)).toBeObservable(cold('a', { a: jasmine.stringMatching(`/collections/${scopeID}/itemtemplate`) }));
+      });
+    });
+
+    describe('createTemplate', () => {
+      it('should forward to CreateDataImpl.createOnEndpoint', () => {
+        spyOn(byCollection, 'getIDHrefObs').and.returnValue('TEST getIDHrefObs');
+
+        const out = byCollection.createTemplate(item, scopeID);
+
+        expect(byCollection.getIDHrefObs).toHaveBeenCalledWith(scopeID);
+        expect(byCollection.createData.createOnEndpoint).toHaveBeenCalledWith(item, 'TEST getIDHrefObs');
+        expect(out).toBe('TEST createOnEndpoint');
       });
     });
   });
+});
+

src/app/core/data/item-template-data.service.ts

@@ -1,147 +1,62 @@
 /* eslint-disable max-classes-per-file */
 import { Injectable } from '@angular/core';
-import { ItemDataService } from './item-data.service';
+import { BaseItemDataService } from './item-data.service';
-import { UpdateDataService } from './update-data.service';
 import { Item } from '../shared/item.model';
-import { RestRequestMethod } from './rest-request-method';
 import { RemoteData } from './remote-data';
 import { Observable } from 'rxjs';
 import { DSOChangeAnalyzer } from './dso-change-analyzer.service';
 import { RequestService } from './request.service';
 import { RemoteDataBuildService } from '../cache/builders/remote-data-build.service';
-import { Store } from '@ngrx/store';
 import { ObjectCacheService } from '../cache/object-cache.service';
 import { HALEndpointService } from '../shared/hal-endpoint.service';
 import { NotificationsService } from '../../shared/notifications/notifications.service';
-import { HttpClient } from '@angular/common/http';
 import { BrowseService } from '../browse/browse.service';
 import { CollectionDataService } from './collection-data.service';
-import { map, switchMap } from 'rxjs/operators';
+import { switchMap } from 'rxjs/operators';
 import { BundleDataService } from './bundle-data.service';
 import { FollowLinkConfig } from '../../shared/utils/follow-link-config.model';
-import { NoContent } from '../shared/NoContent.model';
+import { IdentifiableDataService } from './base/identifiable-data.service';
-import { hasValue } from '../../shared/empty.util';
+import { CreateDataImpl } from './base/create-data';
-import { Operation } from 'fast-json-patch';
-import { getFirstCompletedRemoteData } from '../shared/operators';
-import { CoreState } from '../core-state.model';
 
 /**
- * A custom implementation of the ItemDataService, but for collection item templates
+ * Data service for interacting with Item templates via their Collection
- * Makes sure to change the endpoint before sending out CRUD requests for the item template
  */
-class DataServiceImpl extends ItemDataService {
+class CollectionItemTemplateDataService extends IdentifiableDataService<Item> {
-  protected collectionLinkPath = 'itemtemplate';
+  private createData: CreateDataImpl<Item>;
-  protected linkPath = 'itemtemplates';
-
-  /**
-   * Endpoint dynamically changing depending on what request we're sending
-   */
-  private endpoint$: Observable<string>;
-
-  /**
-   * Is the current endpoint based on a collection?
-   */
-  private collectionEndpoint = false;
 
   constructor(
     protected requestService: RequestService,
     protected rdbService: RemoteDataBuildService,
-    protected store: Store<CoreState>,
-    protected bs: BrowseService,
     protected objectCache: ObjectCacheService,
     protected halService: HALEndpointService,
     protected notificationsService: NotificationsService,
-    protected http: HttpClient,
+    protected collectionService: CollectionDataService,
-    protected comparator: DSOChangeAnalyzer<Item>,
+  ) {
-    protected bundleService: BundleDataService,
+    super('itemtemplates', requestService, rdbService, objectCache, halService, undefined);
-    protected collectionService: CollectionDataService) {
+
-    super(requestService, rdbService, store, bs, objectCache, halService, notificationsService, http, comparator, bundleService);
+    // We only intend to use createOnEndpoint, so this inner data service feature doesn't need an endpoint at all
+    this.createData = new CreateDataImpl<Item>(undefined, requestService, rdbService, objectCache, halService, notificationsService, this.responseMsToLive);
   }
 
   /**
-   * Get the endpoint based on a collection
+   * Create an observable for the HREF of a specific object based on its identifier
-   * @param collectionID  The ID of the collection to base the endpoint on
+   *
+   * Overridden to ensure that {@link findById} works with Collection IDs and points to the template.
+   * @param collectionID  the ID of a Collection
    */
-  public getCollectionEndpoint(collectionID: string): Observable<string> {
+  public getIDHrefObs(collectionID: string): Observable<string> {
     return this.collectionService.getIDHrefObs(collectionID).pipe(
-      switchMap((href: string) => this.halService.getEndpoint(this.collectionLinkPath, href))
+      switchMap((href: string) => this.halService.getEndpoint('itemtemplate', href)),
     );
   }
 
   /**
-   * Set the endpoint to be based on a collection
+   * Create a new item template for a Collection by ID
-   * @param collectionID  The ID of the collection to base the endpoint on
-   */
-  private setCollectionEndpoint(collectionID: string) {
-    this.collectionEndpoint = true;
-    this.endpoint$ = this.getCollectionEndpoint(collectionID);
-  }
-
-  /**
-   * Set the endpoint to the regular linkPath
-   */
-  private setRegularEndpoint() {
-    this.collectionEndpoint = false;
-    this.endpoint$ = this.halService.getEndpoint(this.linkPath);
-  }
-
-  /**
-   * Get the base endpoint for all requests
-   * Uses the current collectionID to assemble a request endpoint for the collection's item template
-   */
-  protected getEndpoint(): Observable<string> {
-    return this.endpoint$;
-  }
-
-  /**
-   * If the current endpoint is based on a collection, simply return the collection's template endpoint, otherwise
-   * create a regular template endpoint
-   * @param resourceID
-   */
-  getIDHrefObs(resourceID: string): Observable<string> {
-    if (this.collectionEndpoint) {
-      return this.getEndpoint();
-    } else {
-      return super.getIDHrefObs(resourceID);
-    }
-  }
-
-  /**
-   * Set the collection ID and send a find by ID request
-   * @param collectionID
-   * @param useCachedVersionIfAvailable If this is true, the request will only be sent if there's
-   *                                    no valid cached version. Defaults to true
-   * @param reRequestOnStale            Whether or not the request should automatically be re-
-   *                                    requested after the response becomes stale
-   * @param linksToFollow               List of {@link FollowLinkConfig} that indicate which
-   *                                    {@link HALLink}s should be automatically resolved
-   */
-  findByCollectionID(collectionID: string, useCachedVersionIfAvailable = true, reRequestOnStale = true, ...linksToFollow: FollowLinkConfig<Item>[]): Observable<RemoteData<Item>> {
-    this.setCollectionEndpoint(collectionID);
-    return super.findById(collectionID, useCachedVersionIfAvailable, reRequestOnStale, ...linksToFollow);
-  }
-
-  /**
-   * Set the collection ID and send a create request
    * @param item
    * @param collectionID
    */
-  createTemplate(item: Item, collectionID: string): Observable<RemoteData<Item>> {
+  public createTemplate(item: Item, collectionID: string): Observable<RemoteData<Item>> {
-    this.setCollectionEndpoint(collectionID);
+    return this.createData.createOnEndpoint(item, this.getIDHrefObs(collectionID));
-    return super.create(item);
-  }
-
-  /**
-   * Set the collection ID and send a delete request
-   * @param item
-   * @param collectionID
-   */
-  deleteByCollectionID(item: Item, collectionID: string): Observable<boolean> {
-    this.setRegularEndpoint();
-    return super.delete(item.uuid).pipe(
-      getFirstCompletedRemoteData(),
-      map((response: RemoteData<NoContent>) => hasValue(response) && response.hasSucceeded)
-    );
   }
 }
 
@@ -149,43 +64,23 @@ class DataServiceImpl extends ItemDataService {
  * A service responsible for fetching/sending data from/to the REST API on a collection's itemtemplates endpoint
  */
 @Injectable()
-export class ItemTemplateDataService implements UpdateDataService<Item> {
+export class ItemTemplateDataService extends BaseItemDataService {
-  /**
+  private byCollection: CollectionItemTemplateDataService;
-   * The data service responsible for all CRUD actions on the item
-   */
-  private dataService: DataServiceImpl;
 
   constructor(
     protected requestService: RequestService,
     protected rdbService: RemoteDataBuildService,
-    protected store: Store<CoreState>,
-    protected bs: BrowseService,
     protected objectCache: ObjectCacheService,
     protected halService: HALEndpointService,
     protected notificationsService: NotificationsService,
-    protected http: HttpClient,
     protected comparator: DSOChangeAnalyzer<Item>,
+    protected browseService: BrowseService,
     protected bundleService: BundleDataService,
-    protected collectionService: CollectionDataService) {
+    protected collectionService: CollectionDataService,
-    this.dataService = new DataServiceImpl(requestService, rdbService, store, bs, objectCache, halService, notificationsService, http, comparator, bundleService, collectionService);
+  ) {
-  }
+    super('itemtemplates', requestService, rdbService, objectCache, halService, notificationsService, comparator, browseService, bundleService);
 
-  /**
+    this.byCollection = new CollectionItemTemplateDataService(requestService, rdbService, objectCache, halService, notificationsService, collectionService);
-   * Commit current object changes to the server
-   */
-  commitUpdates(method?: RestRequestMethod) {
-    this.dataService.commitUpdates(method);
-  }
-
-  /**
-   * Add a new patch to the object cache
-   */
-  update(object: Item): Observable<RemoteData<Item>> {
-    return this.dataService.update(object);
-  }
-
-  patch(dso: Item, operations: Operation[]): Observable<RemoteData<Item>> {
-    return this.dataService.patch(dso, operations);
   }
 
   /**
@@ -199,7 +94,7 @@ export class ItemTemplateDataService implements UpdateDataService<Item> {
    *                                    {@link HALLink}s should be automatically resolved
    */
   findByCollectionID(collectionID: string, useCachedVersionIfAvailable = true, reRequestOnStale = true, ...linksToFollow: FollowLinkConfig<Item>[]): Observable<RemoteData<Item>> {
-    return this.dataService.findByCollectionID(collectionID, useCachedVersionIfAvailable, reRequestOnStale, ...linksToFollow);
+    return this.byCollection.findById(collectionID, useCachedVersionIfAvailable, reRequestOnStale, ...linksToFollow);
   }
 
   /**
@@ -207,17 +102,8 @@ export class ItemTemplateDataService implements UpdateDataService<Item> {
    * @param item
    * @param collectionID
    */
-  create(item: Item, collectionID: string): Observable<RemoteData<Item>> {
+  createByCollectionID(item: Item, collectionID: string): Observable<RemoteData<Item>> {
-    return this.dataService.createTemplate(item, collectionID);
+    return this.byCollection.createTemplate(item, collectionID);
-  }
-
-  /**
-   * Delete a template item by collection ID
-   * @param item
-   * @param collectionID
-   */
-  deleteByCollectionID(item: Item, collectionID: string): Observable<boolean> {
-    return this.dataService.deleteByCollectionID(item, collectionID);
   }
 
   /**
@@ -225,6 +111,6 @@ export class ItemTemplateDataService implements UpdateDataService<Item> {
    * @param collectionID  The ID of the collection to base the endpoint on
    */
   getCollectionEndpoint(collectionID: string): Observable<string> {
-    return this.dataService.getCollectionEndpoint(collectionID);
+    return this.byCollection.getIDHrefObs(collectionID);
   }
 }

src/app/core/data/lookup-relation.service.spec.ts

@@ -1,5 +1,5 @@
 import { LookupRelationService } from './lookup-relation.service';
-import { ExternalSourceService } from './external-source.service';
+import { ExternalSourceDataService } from './external-source-data.service';
 import { SearchService } from '../shared/search/search.service';
 import { createSuccessfulRemoteDataObject$ } from '../../shared/remote-data.utils';
 import { createPaginatedList } from '../../shared/testing/utils.test';
@@ -16,7 +16,7 @@ import { of as observableOf } from 'rxjs';
 
 describe('LookupRelationService', () => {
   let service: LookupRelationService;
-  let externalSourceService: ExternalSourceService;
+  let externalSourceService: ExternalSourceDataService;
   let searchService: SearchService;
   let requestService: RequestService;
 

src/app/core/data/lookup-relation.service.ts

@@ -1,4 +1,4 @@
-import { ExternalSourceService } from './external-source.service';
+import { ExternalSourceDataService } from './external-source-data.service';
 import { SearchService } from '../shared/search/search.service';
 import { concat, distinctUntilChanged, map, multicast, startWith, take, takeWhile } from 'rxjs/operators';
 import { PaginatedSearchOptions } from '../../shared/search/models/paginated-search-options.model';
@@ -34,7 +34,7 @@ export class LookupRelationService {
     pageSize: 1
   });
 
-  constructor(protected externalSourceService: ExternalSourceService,
+  constructor(protected externalSourceService: ExternalSourceDataService,
               protected searchService: SearchService,
               protected requestService: RequestService) {
   }

src/app/core/data/metadata-field-data.service.spec.ts

@@ -10,6 +10,11 @@ import { RemoteDataBuildService } from '../cache/builders/remote-data-build.serv
 import { createSuccessfulRemoteDataObject$ } from '../../shared/remote-data.utils';
 import { RequestParam } from '../cache/models/request-param.model';
 import { FindListOptions } from './find-list-options.model';
+import { createPaginatedList } from '../../shared/testing/utils.test';
+import { testCreateDataImplementation } from './base/create-data.spec';
+import { testSearchDataImplementation } from './base/search-data.spec';
+import { testPutDataImplementation } from './base/put-data.spec';
+import { testDeleteDataImplementation } from './base/delete-data.spec';
 
 describe('MetadataFieldDataService', () => {
   let metadataFieldService: MetadataFieldDataService;
@@ -33,22 +38,33 @@ describe('MetadataFieldDataService', () => {
       generateRequestId: '34cfed7c-f597-49ef-9cbe-ea351f0023c2',
       send: {},
       getByUUID: observableOf({ response: new RestResponse(true, 200, 'OK') }),
-      setStaleByHrefSubstring: {}
+      setStaleByHrefSubstring: {},
     });
     halService = Object.assign(new HALEndpointServiceStub(endpoint));
     notificationsService = jasmine.createSpyObj('notificationsService', {
-      error: {}
+      error: {},
     });
     rdbService = jasmine.createSpyObj('rdbService', {
-      buildSingle: createSuccessfulRemoteDataObject$(undefined)
+      buildSingle: createSuccessfulRemoteDataObject$(undefined),
+      buildList: createSuccessfulRemoteDataObject$(createPaginatedList([])),
     });
-    metadataFieldService = new MetadataFieldDataService(requestService, rdbService, undefined, halService, undefined, undefined, undefined, notificationsService);
+    metadataFieldService = new MetadataFieldDataService(
+      requestService, rdbService, undefined, halService, notificationsService,
+    );
   }
 
   beforeEach(() => {
     init();
   });
 
+  describe('composition', () => {
+    const initService = () => new MetadataFieldDataService(null, null, null, null, null);
+    testCreateDataImplementation(initService);
+    testSearchDataImplementation(initService);
+    testPutDataImplementation(initService);
+    testDeleteDataImplementation(initService);
+  });
+
   describe('findBySchema', () => {
     beforeEach(() => {
       spyOn(metadataFieldService, 'searchBy');

src/app/core/data/metadata-field-data.service.ts

@@ -1,17 +1,10 @@
 import { Injectable } from '@angular/core';
 import { hasValue } from '../../shared/empty.util';
-import { dataService } from '../cache/builders/build-decorators';
-import { DataService } from './data.service';
 import { PaginatedList } from './paginated-list.model';
 import { RemoteData } from './remote-data';
 import { RequestService } from './request.service';
 import { RemoteDataBuildService } from '../cache/builders/remote-data-build.service';
-import { Store } from '@ngrx/store';
 import { HALEndpointService } from '../shared/hal-endpoint.service';
-import { ObjectCacheService } from '../cache/object-cache.service';
-import { DefaultChangeAnalyzer } from './default-change-analyzer.service';
-import { HttpClient } from '@angular/common/http';
-import { NotificationsService } from '../../shared/notifications/notifications.service';
 import { METADATA_FIELD } from '../metadata/metadata-field.resource-type';
 import { MetadataField } from '../metadata/metadata-field.model';
 import { MetadataSchema } from '../metadata/metadata-schema.model';
@@ -19,29 +12,44 @@ import { FollowLinkConfig } from '../../shared/utils/follow-link-config.model';
 import { Observable } from 'rxjs';
 import { take } from 'rxjs/operators';
 import { RequestParam } from '../cache/models/request-param.model';
-import { CoreState } from '../core-state.model';
 import { FindListOptions } from './find-list-options.model';
+import { SearchData, SearchDataImpl } from './base/search-data';
+import { PutData, PutDataImpl } from './base/put-data';
+import { CreateData, CreateDataImpl } from './base/create-data';
+import { NoContent } from '../shared/NoContent.model';
+import { NotificationsService } from '../../shared/notifications/notifications.service';
+import { ObjectCacheService } from '../cache/object-cache.service';
+import { DeleteData, DeleteDataImpl } from './base/delete-data';
+import { IdentifiableDataService } from './base/identifiable-data.service';
+import { dataService } from './base/data-service.decorator';
 
 /**
  * A service responsible for fetching/sending data from/to the REST API on the metadatafields endpoint
  */
 @Injectable()
 @dataService(METADATA_FIELD)
-export class MetadataFieldDataService extends DataService<MetadataField> {
+export class MetadataFieldDataService extends IdentifiableDataService<MetadataField> implements CreateData<MetadataField>, PutData<MetadataField>, DeleteData<MetadataField>, SearchData<MetadataField> {
-  protected linkPath = 'metadatafields';
+  private createData: CreateData<MetadataField>;
+  private searchData: SearchData<MetadataField>;
+  private putData: PutData<MetadataField>;
+  private deleteData: DeleteData<MetadataField>;
+
   protected searchBySchemaLinkPath = 'bySchema';
   protected searchByFieldNameLinkPath = 'byFieldName';
 
   constructor(
     protected requestService: RequestService,
     protected rdbService: RemoteDataBuildService,
-    protected store: Store<CoreState>,
-    protected halService: HALEndpointService,
     protected objectCache: ObjectCacheService,
-    protected comparator: DefaultChangeAnalyzer<MetadataField>,
+    protected halService: HALEndpointService,
-    protected http: HttpClient,
+    protected notificationsService: NotificationsService,
-    protected notificationsService: NotificationsService) {
+  ) {
-    super();
+    super('metadatafields', requestService, rdbService, objectCache, halService);
+
+    this.createData = new CreateDataImpl(this.linkPath, requestService, rdbService, objectCache, halService, notificationsService, this.responseMsToLive);
+    this.searchData = new SearchDataImpl(this.linkPath, requestService, rdbService, objectCache, halService, this.responseMsToLive);
+    this.putData = new PutDataImpl(this.linkPath, requestService, rdbService, objectCache, halService, this.responseMsToLive);
+    this.deleteData = new DeleteDataImpl(this.linkPath, requestService, rdbService, objectCache, halService, notificationsService, this.responseMsToLive, this.constructIdEndpoint);
   }
 
   /**
@@ -57,7 +65,7 @@ export class MetadataFieldDataService extends DataService<MetadataField> {
    */
   findBySchema(schema: MetadataSchema, options: FindListOptions = {}, useCachedVersionIfAvailable = true, reRequestOnStale = true, ...linksToFollow: FollowLinkConfig<MetadataField>[]) {
     const optionsWithSchema = Object.assign(new FindListOptions(), options, {
-      searchParams: [new RequestParam('schema', schema.prefix)]
+      searchParams: [new RequestParam('schema', schema.prefix)],
     });
     return this.searchBy(this.searchBySchemaLinkPath, optionsWithSchema, useCachedVersionIfAvailable, reRequestOnStale, ...linksToFollow);
   }
@@ -85,8 +93,8 @@ export class MetadataFieldDataService extends DataService<MetadataField> {
         new RequestParam('element', hasValue(element) ? element : ''),
         new RequestParam('qualifier', hasValue(qualifier) ? qualifier : ''),
         new RequestParam('query', hasValue(query) ? query : ''),
-        new RequestParam('exactName', hasValue(exactName) ? exactName : '')
+        new RequestParam('exactName', hasValue(exactName) ? exactName : ''),
-      ]
+      ],
     });
     return this.searchBy(this.searchByFieldNameLinkPath, optionParams, useCachedVersionIfAvailable, reRequestOnStale, ...linksToFollow);
   }
@@ -112,4 +120,67 @@ export class MetadataFieldDataService extends DataService<MetadataField> {
 
   }
 
+
+  /**
+   * Delete an existing object on the server
+   * @param   objectId The id of the object to be removed
+   * @param   copyVirtualMetadata (optional parameter) the identifiers of the relationship types for which the virtual
+   *                            metadata should be saved as real metadata
+   * @return  A RemoteData observable with an empty payload, but still representing the state of the request: statusCode,
+   *          errorMessage, timeCompleted, etc
+   */
+  delete(objectId: string, copyVirtualMetadata?: string[]): Observable<RemoteData<NoContent>> {
+    return this.deleteData.delete(objectId, copyVirtualMetadata);
+  }
+
+  /**
+   * Delete an existing object on the server
+   * @param   href The self link of the object to be removed
+   * @param   copyVirtualMetadata (optional parameter) the identifiers of the relationship types for which the virtual
+   *                            metadata should be saved as real metadata
+   * @return  A RemoteData observable with an empty payload, but still representing the state of the request: statusCode,
+   *          errorMessage, timeCompleted, etc
+   *          Only emits once all request related to the DSO has been invalidated.
+   */
+  public deleteByHref(href: string, copyVirtualMetadata?: string[]): Observable<RemoteData<NoContent>> {
+    return this.deleteData.deleteByHref(href, copyVirtualMetadata);
+  }
+
+  /**
+   * Send a PUT request for the specified object
+   *
+   * @param object The object to send a put request for.
+   */
+  put(object: MetadataField): Observable<RemoteData<MetadataField>> {
+    return this.putData.put(object);
+  }
+
+  /**
+   * Create a new object on the server, and store the response in the object cache
+   *
+   * @param object    The object to create
+   * @param params    Array with additional params to combine with query string
+   */
+  create(object: MetadataField, ...params: RequestParam[]): Observable<RemoteData<MetadataField>> {
+    return this.createData.create(object, ...params);
+  }
+
+  /**
+   * Make a new FindListRequest with given search method
+   *
+   * @param searchMethod                The search method for the object
+   * @param options                     The [[FindListOptions]] object
+   * @param useCachedVersionIfAvailable If this is true, the request will only be sent if there's
+   *                                    no valid cached version. Defaults to true
+   * @param reRequestOnStale            Whether or not the request should automatically be re-
+   *                                    requested after the response becomes stale
+   * @param linksToFollow               List of {@link FollowLinkConfig} that indicate which
+   *                                    {@link HALLink}s should be automatically resolved
+   * @return {Observable<RemoteData<PaginatedList<T>>}
+   *    Return an observable that emits response from the server
+   */
+  public searchBy(searchMethod: string, options?: FindListOptions, useCachedVersionIfAvailable?: boolean, reRequestOnStale?: boolean, ...linksToFollow: FollowLinkConfig<MetadataField>[]): Observable<RemoteData<PaginatedList<MetadataField>>> {
+    return this.searchData.searchBy(searchMethod, options, useCachedVersionIfAvailable, reRequestOnStale, ...linksToFollow);
+  }
+
 }

src/app/core/data/metadata-schema-data.service.spec.ts

@@ -9,6 +9,8 @@ import { MetadataSchema } from '../metadata/metadata-schema.model';
 import { CreateRequest, PutRequest } from './request.models';
 import { RemoteDataBuildService } from '../cache/builders/remote-data-build.service';
 import { getMockRemoteDataBuildService } from '../../shared/mocks/remote-data-build.service.mock';
+import { testFindAllDataImplementation } from './base/find-all-data.spec';
+import { testDeleteDataImplementation } from './base/delete-data.spec';
 
 describe('MetadataSchemaDataService', () => {
   let metadataSchemaService: MetadataSchemaDataService;
@@ -24,20 +26,33 @@ describe('MetadataSchemaDataService', () => {
       generateRequestId: '34cfed7c-f597-49ef-9cbe-ea351f0023c2',
       send: {},
       getByUUID: observableOf({ response: new RestResponse(true, 200, 'OK') }),
-      removeByHrefSubstring: {}
+      removeByHrefSubstring: {},
     });
     halService = Object.assign(new HALEndpointServiceStub(endpoint));
     notificationsService = jasmine.createSpyObj('notificationsService', {
-      error: {}
+      error: {},
     });
     rdbService = getMockRemoteDataBuildService();
-    metadataSchemaService = new MetadataSchemaDataService(requestService, rdbService, undefined, halService, undefined, undefined, undefined, notificationsService);
+    metadataSchemaService = new MetadataSchemaDataService(
+      requestService,
+      rdbService,
+      null,
+      halService,
+      notificationsService,
+    );
   }
 
   beforeEach(() => {
     init();
   });
 
+  describe('composition', () => {
+    const initService = () => new MetadataSchemaDataService(null, null, null, null, null);
+
+    testFindAllDataImplementation(initService);
+    testDeleteDataImplementation(initService);
+  });
+
   describe('createOrUpdateMetadataSchema', () => {
     let schema: MetadataSchema;
 

src/app/core/data/metadata-schema-data.service.ts

@@ -1,40 +1,50 @@
-import { HttpClient } from '@angular/common/http';
 import { Injectable } from '@angular/core';
-import { Store } from '@ngrx/store';
 import { NotificationsService } from '../../shared/notifications/notifications.service';
-import { dataService } from '../cache/builders/build-decorators';
 import { RemoteDataBuildService } from '../cache/builders/remote-data-build.service';
 import { ObjectCacheService } from '../cache/object-cache.service';
 import { MetadataSchema } from '../metadata/metadata-schema.model';
 import { METADATA_SCHEMA } from '../metadata/metadata-schema.resource-type';
 import { HALEndpointService } from '../shared/hal-endpoint.service';
-import { DataService } from './data.service';
-import { DefaultChangeAnalyzer } from './default-change-analyzer.service';
 import { RequestService } from './request.service';
 import { Observable } from 'rxjs';
 import { hasValue } from '../../shared/empty.util';
 import { tap } from 'rxjs/operators';
 import { RemoteData } from './remote-data';
-import { CoreState } from '../core-state.model';
+import { PutData, PutDataImpl } from './base/put-data';
+import { CreateData, CreateDataImpl } from './base/create-data';
+import { NoContent } from '../shared/NoContent.model';
+import { FindAllData, FindAllDataImpl } from './base/find-all-data';
+import { FindListOptions } from './find-list-options.model';
+import { FollowLinkConfig } from '../../shared/utils/follow-link-config.model';
+import { PaginatedList } from './paginated-list.model';
+import { IdentifiableDataService } from './base/identifiable-data.service';
+import { DeleteData, DeleteDataImpl } from './base/delete-data';
+import { dataService } from './base/data-service.decorator';
 
 /**
  * A service responsible for fetching/sending data from/to the REST API on the metadataschemas endpoint
  */
 @Injectable()
 @dataService(METADATA_SCHEMA)
-export class MetadataSchemaDataService extends DataService<MetadataSchema> {
+export class MetadataSchemaDataService extends IdentifiableDataService<MetadataSchema> implements FindAllData<MetadataSchema>, DeleteData<MetadataSchema> {
-  protected linkPath = 'metadataschemas';
+  private createData: CreateData<MetadataSchema>;
+  private findAllData: FindAllData<MetadataSchema>;
+  private putData: PutData<MetadataSchema>;
+  private deleteData: DeleteData<MetadataSchema>;
 
   constructor(
     protected requestService: RequestService,
     protected rdbService: RemoteDataBuildService,
-    protected store: Store<CoreState>,
-    protected halService: HALEndpointService,
     protected objectCache: ObjectCacheService,
-    protected comparator: DefaultChangeAnalyzer<MetadataSchema>,
+    protected halService: HALEndpointService,
-    protected http: HttpClient,
+    protected notificationsService: NotificationsService,
-    protected notificationsService: NotificationsService) {
+  ) {
-    super();
+    super('metadataschemas', requestService, rdbService, objectCache, halService);
+
+    this.createData = new CreateDataImpl(this.linkPath, requestService, rdbService, objectCache, halService, notificationsService, this.responseMsToLive);
+    this.putData = new PutDataImpl(this.linkPath, requestService, rdbService, objectCache, halService, this.responseMsToLive);
+    this.deleteData = new DeleteDataImpl(this.linkPath, requestService, rdbService, objectCache, halService, notificationsService, this.responseMsToLive, this.constructIdEndpoint);
+    this.findAllData = new FindAllDataImpl(this.linkPath, requestService, rdbService, objectCache, halService, this.responseMsToLive);
   }
 
   /**
@@ -49,9 +59,9 @@ export class MetadataSchemaDataService extends DataService<MetadataSchema> {
     const isUpdate = hasValue(schema.id);
 
     if (isUpdate) {
-      return this.put(schema);
+      return this.putData.put(schema);
     } else {
-      return this.create(schema);
+      return this.createData.create(schema);
     }
   }
 
@@ -61,8 +71,50 @@ export class MetadataSchemaDataService extends DataService<MetadataSchema> {
    */
   clearRequests(): Observable<string> {
     return this.getBrowseEndpoint().pipe(
-      tap((href: string) => this.requestService.removeByHrefSubstring(href))
+      tap((href: string) => this.requestService.removeByHrefSubstring(href)),
     );
   }
 
+  /**
+   * Returns {@link RemoteData} of all object with a list of {@link FollowLinkConfig}, to indicate which embedded
+   * info should be added to the objects
+   *
+   * @param options                     Find list options object
+   * @param useCachedVersionIfAvailable If this is true, the request will only be sent if there's
+   *                                    no valid cached version. Defaults to true
+   * @param reRequestOnStale            Whether or not the request should automatically be re-
+   *                                    requested after the response becomes stale
+   * @param linksToFollow               List of {@link FollowLinkConfig} that indicate which
+   *                                    {@link HALLink}s should be automatically resolved
+   * @return {Observable<RemoteData<PaginatedList<T>>>}
+   *    Return an observable that emits object list
+   */
+  public findAll(options?: FindListOptions, useCachedVersionIfAvailable?: boolean, reRequestOnStale?: boolean, ...linksToFollow: FollowLinkConfig<MetadataSchema>[]): Observable<RemoteData<PaginatedList<MetadataSchema>>> {
+    return this.findAllData.findAll(options, useCachedVersionIfAvailable, reRequestOnStale, ...linksToFollow);
+  }
+
+  /**
+   * Delete an existing object on the server
+   * @param   objectId The id of the object to be removed
+   * @param   copyVirtualMetadata (optional parameter) the identifiers of the relationship types for which the virtual
+   *                            metadata should be saved as real metadata
+   * @return  A RemoteData observable with an empty payload, but still representing the state of the request: statusCode,
+   *          errorMessage, timeCompleted, etc
+   */
+  public delete(objectId: string, copyVirtualMetadata?: string[]): Observable<RemoteData<NoContent>> {
+    return this.deleteData.delete(objectId, copyVirtualMetadata);
+  }
+
+  /**
+   * Delete an existing object on the server
+   * @param   href The self link of the object to be removed
+   * @param   copyVirtualMetadata (optional parameter) the identifiers of the relationship types for which the virtual
+   *                            metadata should be saved as real metadata
+   * @return  A RemoteData observable with an empty payload, but still representing the state of the request: statusCode,
+   *          errorMessage, timeCompleted, etc
+   *          Only emits once all request related to the DSO has been invalidated.
+   */
+  public deleteByHref(href: string, copyVirtualMetadata?: string[]): Observable<RemoteData<NoContent>> {
+    return this.deleteData.deleteByHref(href, copyVirtualMetadata);
+  }
 }

src/app/core/data/processes/process-data.service.spec.ts

@@ -0,0 +1,19 @@
+/**
+ * The contents of this file are subject to the license and copyright
+ * detailed in the LICENSE and NOTICE files at the root of the source
+ * tree and available online at
+ *
+ * http://www.dspace.org/license/
+ */
+
+import { testFindAllDataImplementation } from '../base/find-all-data.spec';
+import { ProcessDataService } from './process-data.service';
+import { testDeleteDataImplementation } from '../base/delete-data.spec';
+
+describe('ProcessDataService', () => {
+  describe('composition', () => {
+    const initService = () => new ProcessDataService(null, null, null, null, null, null);
+    testFindAllDataImplementation(initService);
+    testDeleteDataImplementation(initService);
+  });
+});

src/app/core/data/processes/process-data.service.ts

@@ -1,15 +1,9 @@
 import { Injectable } from '@angular/core';
-import { DataService } from '../data.service';
 import { RequestService } from '../request.service';
 import { RemoteDataBuildService } from '../../cache/builders/remote-data-build.service';
-import { Store } from '@ngrx/store';
 import { ObjectCacheService } from '../../cache/object-cache.service';
 import { HALEndpointService } from '../../shared/hal-endpoint.service';
-import { NotificationsService } from '../../../shared/notifications/notifications.service';
-import { HttpClient } from '@angular/common/http';
-import { DefaultChangeAnalyzer } from '../default-change-analyzer.service';
 import { Process } from '../../../process-page/processes/process.model';
-import { dataService } from '../../cache/builders/build-decorators';
 import { PROCESS } from '../../../process-page/processes/process.resource-type';
 import { Observable } from 'rxjs';
 import { switchMap } from 'rxjs/operators';
@@ -17,24 +11,33 @@ import { PaginatedList } from '../paginated-list.model';
 import { Bitstream } from '../../shared/bitstream.model';
 import { RemoteData } from '../remote-data';
 import { BitstreamDataService } from '../bitstream-data.service';
-import { CoreState } from '../../core-state.model';
+import { IdentifiableDataService } from '../base/identifiable-data.service';
+import { FollowLinkConfig } from '../../../shared/utils/follow-link-config.model';
+import { FindAllData, FindAllDataImpl } from '../base/find-all-data';
+import { FindListOptions } from '../find-list-options.model';
+import { dataService } from '../base/data-service.decorator';
+import { DeleteData, DeleteDataImpl } from '../base/delete-data';
+import { NotificationsService } from '../../../shared/notifications/notifications.service';
+import { NoContent } from '../../shared/NoContent.model';
 
 @Injectable()
 @dataService(PROCESS)
-export class ProcessDataService extends DataService<Process> {
+export class ProcessDataService extends IdentifiableDataService<Process> implements FindAllData<Process>, DeleteData<Process> {
-  protected linkPath = 'processes';
+  private findAllData: FindAllData<Process>;
+  private deleteData: DeleteData<Process>;
 
   constructor(
     protected requestService: RequestService,
     protected rdbService: RemoteDataBuildService,
-    protected store: Store<CoreState>,
     protected objectCache: ObjectCacheService,
     protected halService: HALEndpointService,
-    protected notificationsService: NotificationsService,
     protected bitstreamDataService: BitstreamDataService,
-    protected http: HttpClient,
+    protected notificationsService: NotificationsService,
-    protected comparator: DefaultChangeAnalyzer<Process>) {
+  ) {
-    super();
+    super('processes', requestService, rdbService, objectCache, halService);
+
+    this.findAllData = new FindAllDataImpl(this.linkPath, requestService, rdbService, objectCache, halService, this.responseMsToLive);
+    this.deleteData = new DeleteDataImpl(this.linkPath, requestService, rdbService, objectCache, halService, notificationsService, this.responseMsToLive, this.constructIdEndpoint);
   }
 
   /**
@@ -53,6 +56,49 @@ export class ProcessDataService extends DataService<Process> {
    */
   getFiles(processId: string): Observable<RemoteData<PaginatedList<Bitstream>>> {
     const href$ = this.getFilesEndpoint(processId);
-    return this.bitstreamDataService.findAllByHref(href$);
+    return this.bitstreamDataService.findListByHref(href$);
+  }
+
+  /**
+   * Returns {@link RemoteData} of all object with a list of {@link FollowLinkConfig}, to indicate which embedded
+   * info should be added to the objects
+   *
+   * @param options                     Find list options object
+   * @param useCachedVersionIfAvailable If this is true, the request will only be sent if there's
+   *                                    no valid cached version. Defaults to true
+   * @param reRequestOnStale            Whether or not the request should automatically be re-
+   *                                    requested after the response becomes stale
+   * @param linksToFollow               List of {@link FollowLinkConfig} that indicate which
+   *                                    {@link HALLink}s should be automatically resolved
+   * @return {Observable<RemoteData<PaginatedList<T>>>}
+   *    Return an observable that emits object list
+   */
+  findAll(options?: FindListOptions, useCachedVersionIfAvailable?: boolean, reRequestOnStale?: boolean, ...linksToFollow: FollowLinkConfig<Process>[]): Observable<RemoteData<PaginatedList<Process>>> {
+    return this.findAllData.findAll(options, useCachedVersionIfAvailable, reRequestOnStale, ...linksToFollow);
+  }
+
+  /**
+   * Delete an existing object on the server
+   * @param   objectId The id of the object to be removed
+   * @param   copyVirtualMetadata (optional parameter) the identifiers of the relationship types for which the virtual
+   *                            metadata should be saved as real metadata
+   * @return  A RemoteData observable with an empty payload, but still representing the state of the request: statusCode,
+   *          errorMessage, timeCompleted, etc
+   */
+  public delete(objectId: string, copyVirtualMetadata?: string[]): Observable<RemoteData<NoContent>> {
+    return this.deleteData.delete(objectId, copyVirtualMetadata);
+  }
+
+  /**
+   * Delete an existing object on the server
+   * @param   href The self link of the object to be removed
+   * @param   copyVirtualMetadata (optional parameter) the identifiers of the relationship types for which the virtual
+   *                            metadata should be saved as real metadata
+   * @return  A RemoteData observable with an empty payload, but still representing the state of the request: statusCode,
+   *          errorMessage, timeCompleted, etc
+   *          Only emits once all request related to the DSO has been invalidated.
+   */
+  public deleteByHref(href: string, copyVirtualMetadata?: string[]): Observable<RemoteData<NoContent>> {
+    return this.deleteData.deleteByHref(href, copyVirtualMetadata);
   }
 }

src/app/core/data/processes/script-data.service.spec.ts

@@ -0,0 +1,17 @@
+/**
+ * The contents of this file are subject to the license and copyright
+ * detailed in the LICENSE and NOTICE files at the root of the source
+ * tree and available online at
+ *
+ * http://www.dspace.org/license/
+ */
+
+import { testFindAllDataImplementation } from '../base/find-all-data.spec';
+import { ScriptDataService } from './script-data.service';
+
+describe('ScriptDataService', () => {
+  describe('composition', () => {
+    const initService = () => new ScriptDataService(null, null, null, null);
+    testFindAllDataImplementation(initService);
+  });
+});

src/app/core/data/processes/script-data.service.ts

@@ -1,12 +1,7 @@
 import { Injectable } from '@angular/core';
-import { DataService } from '../data.service';
 import { RemoteDataBuildService } from '../../cache/builders/remote-data-build.service';
-import { Store } from '@ngrx/store';
 import { ObjectCacheService } from '../../cache/object-cache.service';
 import { HALEndpointService } from '../../shared/hal-endpoint.service';
-import { NotificationsService } from '../../../shared/notifications/notifications.service';
-import { HttpClient } from '@angular/common/http';
-import { DefaultChangeAnalyzer } from '../default-change-analyzer.service';
 import { Script } from '../../../process-page/scripts/script.model';
 import { ProcessParameter } from '../../../process-page/processes/process-parameter.model';
 import { map, take } from 'rxjs/operators';
@@ -15,32 +10,35 @@ import { RemoteData } from '../remote-data';
 import { MultipartPostRequest } from '../request.models';
 import { RequestService } from '../request.service';
 import { Observable } from 'rxjs';
-import { dataService } from '../../cache/builders/build-decorators';
 import { SCRIPT } from '../../../process-page/scripts/script.resource-type';
 import { Process } from '../../../process-page/processes/process.model';
 import { hasValue } from '../../../shared/empty.util';
 import { getFirstCompletedRemoteData } from '../../shared/operators';
 import { RestRequest } from '../rest-request.model';
-import { CoreState } from '../../core-state.model';
+import { IdentifiableDataService } from '../base/identifiable-data.service';
+import { FindAllData, FindAllDataImpl } from '../base/find-all-data';
+import { FindListOptions } from '../find-list-options.model';
+import { FollowLinkConfig } from '../../../shared/utils/follow-link-config.model';
+import { PaginatedList } from '../paginated-list.model';
+import { dataService } from '../base/data-service.decorator';
 
 export const METADATA_IMPORT_SCRIPT_NAME = 'metadata-import';
 export const METADATA_EXPORT_SCRIPT_NAME = 'metadata-export';
 
 @Injectable()
 @dataService(SCRIPT)
-export class ScriptDataService extends DataService<Script> {
+export class ScriptDataService extends IdentifiableDataService<Script> implements FindAllData<Script> {
-  protected linkPath = 'scripts';
+  private findAllData: FindAllDataImpl<Script>;
 
   constructor(
     protected requestService: RequestService,
     protected rdbService: RemoteDataBuildService,
-    protected store: Store<CoreState>,
     protected objectCache: ObjectCacheService,
     protected halService: HALEndpointService,
-    protected notificationsService: NotificationsService,
+  ) {
-    protected http: HttpClient,
+    super('scripts', requestService, rdbService, objectCache, halService);
-    protected comparator: DefaultChangeAnalyzer<Script>) {
+
-    super();
+    this.findAllData = new FindAllDataImpl(this.linkPath, requestService, rdbService, objectCache, halService, this.responseMsToLive);
   }
 
   public invoke(scriptName: string, parameters: ProcessParameter[], files: File[]): Observable<RemoteData<Process>> {
@@ -75,6 +73,25 @@ export class ScriptDataService extends DataService<Script> {
       getFirstCompletedRemoteData(),
       map((rd: RemoteData<Script>) => {
         return hasValue(rd.payload);
-      }));
+      }),
+    );
+  }
+
+  /**
+   * Returns {@link RemoteData} of all object with a list of {@link FollowLinkConfig}, to indicate which embedded
+   * info should be added to the objects
+   *
+   * @param options                     Find list options object
+   * @param useCachedVersionIfAvailable If this is true, the request will only be sent if there's
+   *                                    no valid cached version. Defaults to true
+   * @param reRequestOnStale            Whether or not the request should automatically be re-
+   *                                    requested after the response becomes stale
+   * @param linksToFollow               List of {@link FollowLinkConfig} that indicate which
+   *                                    {@link HALLink}s should be automatically resolved
+   * @return {Observable<RemoteData<PaginatedList<T>>>}
+   *    Return an observable that emits object list
+   */
+  public findAll(options?: FindListOptions, useCachedVersionIfAvailable?: boolean, reRequestOnStale?: boolean, ...linksToFollow: FollowLinkConfig<Script>[]): Observable<RemoteData<PaginatedList<Script>>> {
+    return this.findAllData.findAll(options, useCachedVersionIfAvailable, reRequestOnStale, ...linksToFollow);
   }
 }