93803: Refactor existing data services

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$.pipe(
+      getFirstSucceededRemoteDataPayload(),
-      switchMap((collection: Collection) => this.itemTemplateService.findByCollectionID(collection.uuid).pipe(
+      switchMap((template) => {
-        getFirstSucceededRemoteDataPayload(),
+        return this.itemTemplateService.delete(template.uuid);
-      )),
+      }),
-    );
+      getFirstCompletedRemoteData(),
-    combineLatestObservable(collection$, template$).pipe(
+      map((response: RemoteData<NoContent>) => hasValue(response) && response.hasSucceeded),
-      switchMap(([collection, template]) => {
-        return this.itemTemplateService.deleteByCollectionID(template, collection.uuid);
-      })
     ).subscribe((success: boolean) => {
       if (success) {
         this.notificationsService.success(null, this.translate.get('collection.edit.template.notifications.delete.success'));

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>,
+  ) {
   }
 
   /**
@@ -36,7 +39,7 @@ export abstract class DSOBreadcrumbResolver<T extends ChildHALResource & DSpaceO
         if (hasValue(object)) {
           const fullPath = state.url;
           const url = fullPath.substr(0, fullPath.indexOf(uuid)) + uuid;
-          return {provider: this.breadcrumbService, key: object, url: url};
+          return { provider: this.breadcrumbService, key: object, url: url };
         } else {
           return undefined;
         }

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

@@ -1,125 +1,40 @@
-/* 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';
-class DataServiceImpl extends DataService<BrowseDefinition> {
-  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);
   }
 
-  /**
+
-   * 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<BrowseDefinition>>>}
-   *    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/config/config.service.spec.ts

@@ -9,6 +9,7 @@ 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';
@@ -20,8 +21,10 @@ class TestService extends ConfigService {
   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);
   }
 }
 
@@ -45,7 +48,8 @@ describe('ConfigService', () => {
     return new TestService(
       requestService,
       rdbService,
-      halService
+      null,
+      halService,
     );
   }
 

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

@@ -1,59 +1,14 @@
-/* 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';
+import { BaseDataService } from '../data/base/base-data.service';
-
-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);
-  }
 
+export abstract class ConfigService extends BaseDataService<ConfigObject> {
   public findByHref(href: string, useCachedVersionIfAvailable = true, reRequestOnStale = true, ...linksToFollow: FollowLinkConfig<ConfigObject>[]): Observable<RemoteData<ConfigObject>> {
-    return this.dataService.findByHref(href, useCachedVersionIfAvailable, reRequestOnStale, ...linksToFollow).pipe(
+    return super.findByHref(href, useCachedVersionIfAvailable, reRequestOnStale, ...linksToFollow).pipe(
       getFirstCompletedRemoteData(),
       map((rd: RemoteData<ConfigObject>) => {
         if (rd.hasFailed) {
@@ -61,7 +16,7 @@ export abstract class ConfigService {
         } else {
           return rd;
         }
-      })
+      }),
     );
   }
 }

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

@@ -26,14 +26,10 @@ export class SubmissionAccessesConfigService extends ConfigService {
   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);
   }
 
   findByHref(href: string, useCachedVersionIfAvailable = true, reRequestOnStale = true, ...linksToFollow): Observable<RemoteData<SubmissionAccessesModel>> {

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

@@ -4,11 +4,7 @@ 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';
@@ -16,7 +12,6 @@ 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';
 
 @Injectable()
 @dataService(SUBMISSION_FORMS_TYPE)
@@ -24,14 +19,10 @@ export class SubmissionFormsConfigService extends ConfigService {
   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);
   }
 
   public findByHref(href: string, useCachedVersionIfAvailable = true, reRequestOnStale = true, ...linksToFollow: FollowLinkConfig<SubmissionFormsModel>[]): Observable<RemoteData<SubmissionFormsModel>> {

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

@@ -6,16 +6,11 @@ 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';
 
 /**
  * Provides methods to retrieve, from REST server, bitstream access conditions configurations applicable during the submission process.
@@ -26,14 +21,10 @@ export class SubmissionUploadsConfigService extends ConfigService {
   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

@@ -178,6 +178,8 @@ 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
@@ -300,6 +302,8 @@ const PROVIDERS = [
   FilteredDiscoveryPageResponseParsingService,
   { provide: NativeWindowService, useFactory: NativeWindowFactory },
   VocabularyService,
+  VocabularyDataService,
+  VocabularyEntryDetailsDataService,
   VocabularyTreeviewService,
   SequenceService,
   GroupDataService,

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 +1,27 @@
-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';
 
 @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/bitstream-data.service.spec.ts

@@ -47,7 +47,7 @@ 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('when updating the bitstream\'s format', () => {

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

@@ -1,10 +1,8 @@
-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';
@@ -15,8 +13,6 @@ 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 +24,43 @@ 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';
 
 /**
  * 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);
   }
 
   /**
@@ -180,8 +183,89 @@ 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);
+  }
+
+  /**
+   * 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

@@ -50,8 +50,6 @@ describe('BitstreamFormatDataService', () => {
   } as HALEndpointService;
 
   const notificationsService = {} as NotificationsService;
-  const http = {} as HttpClient;
-  const comparator = {} as any;
 
   let rd;
   let rdbService: RemoteDataBuildService;
@@ -65,12 +63,10 @@ describe('BitstreamFormatDataService', () => {
     return new BitstreamFormatDataService(
       requestService,
       rdbService,
-      store,
       objectCache,
       halService,
       notificationsService,
-      http,
+      store,
-      comparator
     );
   }
 

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

@@ -1,13 +1,8 @@
-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';
@@ -18,40 +13,52 @@ 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';
 
 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

@@ -64,9 +64,6 @@ describe('BundleDataService', () => {
       store,
       objectCache,
       halService,
-      notificationsService,
-      http,
-      comparator,
     );
   }
 

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

@@ -1,10 +1,7 @@
-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';
@@ -13,8 +10,6 @@ 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 +17,35 @@ 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';
 
 /**
  * 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);
   }
 
   /**
@@ -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 +141,30 @@ 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);
+  }
 }

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

@@ -201,7 +201,7 @@ 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';
@@ -33,30 +32,27 @@ 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';
 
 @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);
   }
 
   /**
@@ -289,10 +285,10 @@ export class CollectionDataService extends ComColDataService<Collection> {
 
 
   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

@@ -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> {

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 +16,44 @@ 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';
 
-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
@@ -129,4 +161,128 @@ 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);
+  }
+
+  /**
+   * 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> {
+    return this.findAllData.getFindAllHref(options, linkPath, ...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> {
+    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<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);
+  }
+
+  /**
+   * 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

@@ -1,7 +1,5 @@
-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';
@@ -19,27 +17,23 @@ 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';
 
 @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);
   }
 
   getEndpoint() {

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';
-
-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/dso-redirect-data.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
-    it('should return endpoint', () => {
+    describe('getIDHref', () => {  // todo: should be able to move this up to IdentifiableDataService?
-      const result = (service as any).getIDHref(pidLink, dsoUUID);
+      it('should return endpoint', () => {
-      expect(result).toEqual(requestUUIDURL);
+        const result = (service as any).dataService.getIDHref(pidLink, dsoUUID);
-    });
+        expect(result).toEqual(requestUUIDURL);
+      });
 
-    it('should include single linksToFollow as embed', () => {
+      it('should include single linksToFollow as embed', () => {
-      const expected = `${requestUUIDURL}&embed=bundles`;
+        const expected = `${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);
+        expect(result).toEqual(expected);
-    });
+      });
 
-    it('should include multiple linksToFollow as embed', () => {
+      it('should include multiple linksToFollow as embed', () => {
-      const expected = `${requestUUIDURL}&embed=bundles&embed=owningCollection&embed=templateItemOf`;
+        const expected = `${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);
+        expect(result).toEqual(expected);
-    });
+      });
 
-    it('should not include linksToFollow with shouldEmbed = false', () => {
+      it('should not include linksToFollow with shouldEmbed = false', () => {
-      const expected = `${requestUUIDURL}&embed=templateItemOf`;
+        const expected = `${requestUUIDURL}&embed=templateItemOf`;
-      const result = (service as any).getIDHref(
+        const result = (service as any).dataService.getIDHref(
-        pidLink,
+          pidLink,
-        dsoUUID,
+          dsoUUID,
-        followLink('bundles', { shouldEmbed: false }),
+          followLink('bundles', { shouldEmbed: false }),
-        followLink('owningCollection', { shouldEmbed: false }),
+          followLink('owningCollection', { shouldEmbed: false }),
-        followLink('templateItemOf')
+          followLink('templateItemOf'),
-      );
+        );
-      expect(result).toEqual(expected);
+        expect(result).toEqual(expected);
-    });
+      });
 
-    it('should include nested linksToFollow 3lvl', () => {
+      it('should include nested linksToFollow 3lvl', () => {
-      const expected = `${requestUUIDURL}&embed=owningCollection/itemtemplate/relationships`;
+        const expected = `${requestUUIDURL}&embed=owningCollection/itemtemplate/relationships`;
-      const result = (service as any).getIDHref(
+        const result = (service as any).dataService.getIDHref(
-        pidLink,
+          pidLink,
-        dsoUUID,
+          dsoUUID,
-        followLink('owningCollection',
+          followLink(
-          {},
+            'owningCollection',
-          followLink('itemtemplate',
             {},
-            followLink('relationships')
+            followLink(
-          )
+              'itemtemplate',
-        )
+              {},
-      );
+              followLink('relationships'),
-      expect(result).toEqual(expected);
+            ),
+          ),
+        );
+        expect(result).toEqual(expected);
+      });
     });
   });
-
 });

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.ts

@@ -0,0 +1,90 @@
+/**
+ * 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';
+
+class DsoByIdOrUUIDService 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;
+    }
+  }
+}
+
+@Injectable()
+export class DsoRedirectService {
+  private dataService: DsoByIdOrUUIDService;
+
+  constructor(
+    protected requestService: RequestService,
+    protected rdbService: RemoteDataBuildService,
+    protected objectCache: ObjectCacheService,
+    protected halService: HALEndpointService,
+    private router: Router,
+  ) {
+    this.dataService = new DsoByIdOrUUIDService(requestService, rdbService, objectCache, halService);
+  }
+
+  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 { 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.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';
@@ -17,27 +12,30 @@ 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 { 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 EntityTypeService extends BaseDataService<ItemType> implements FindAllData<ItemType>, SearchData<ItemType> {
+  private findAllData: FindAllData<ItemType>;
+  private searchData: SearchDataImpl<ItemType>;
 
-  protected linkPath = 'entitytypes';
+  constructor(
+    protected requestService: RequestService,
+    protected rdbService: RemoteDataBuildService,
+    protected objectCache: ObjectCacheService,
+    protected halService: HALEndpointService,
+    protected relationshipTypeService: RelationshipTypeService,
+  ) {
+    super('entitytypes', requestService, rdbService, objectCache, halService);
 
-  constructor(protected requestService: RequestService,
+    this.findAllData = new FindAllDataImpl(this.linkPath, requestService, rdbService, objectCache, halService, this.responseMsToLive);
-              protected rdbService: RemoteDataBuildService,
+    this.searchData = new SearchDataImpl(this.linkPath, requestService, rdbService, objectCache, halService, this.responseMsToLive);
-              protected store: Store<CoreState>,
-              protected halService: HALEndpointService,
-              protected objectCache: ObjectCacheService,
-              protected notificationsService: NotificationsService,
-              protected relationshipTypeService: RelationshipTypeService,
-              protected http: HttpClient,
-              protected comparator: DefaultChangeAnalyzer<ItemType>) {
-    super();
   }
 
   getBrowseEndpoint(options, linkPath?: string): Observable<string> {
@@ -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',
-    providedIn: 'root',
+})
-  }
-)
 /**
  * Service that will register a new email address and request a token
  */

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

@@ -48,9 +48,9 @@ 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 ExternalSourceService(requestService, rdbService, undefined, halService);
   }
 
   beforeEach(() => {

src/app/core/data/external-source.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 ExternalSourceService 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;
   }
+
+  /**
+   * 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 undefined;
+  }
 }

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';
@@ -16,7 +15,6 @@ import { FindListOptions } from '../find-list-options.model';
 describe('AuthorizationDataService', () => {
   let service: AuthorizationDataService;
   let siteService: SiteDataService;
-  let authService: AuthService;
 
   let site: Site;
   let ePerson: EPerson;
@@ -37,13 +35,9 @@ 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(() => {

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

@@ -2,17 +2,11 @@ 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 +18,31 @@ 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';
 
 /**
  * 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 { 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);
       });

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

@@ -1,13 +1,7 @@
-/* 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';
@@ -18,25 +12,8 @@ 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> {
-  // linkPath isn't used if we're only searching by href.
-  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
@@ -46,24 +23,25 @@ class DataServiceImpl extends DataService<any> {
  * an @dataService annotation can be added for any number of these resource types
  */
 @Injectable({
-  providedIn: 'root'
+  providedIn: 'root',
 })
 @dataService(VOCABULARY_ENTRY)
 @dataService(ITEM_TYPE)
 @dataService(LICENSE)
 export class HrefOnlyDataService {
-  private dataService: DataServiceImpl;
+  /**
+   * Not all BaseDataService methods should be exposed, so
+   * @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);
   }
 
   /**

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

@@ -21,7 +21,7 @@ import { HALEndpointServiceStub } from 'src/app/shared/testing/hal-endpoint-serv
 describe('ItemDataService', () => {
   let scheduler: TestScheduler;
   let service: ItemDataService;
-  let bs: BrowseService;
+  let browseService: BrowseService;
   const requestService = Object.assign(getMockRequestService(), {
     generateRequestId(): string {
       return scopeID;
@@ -78,14 +78,12 @@ describe('ItemDataService', () => {
     return new ItemDataService(
       requestService,
       rdbService,
-      store,
-      bs,
       objectCache,
       halEndpointService,
       notificationsService,
-      http,
       comparator,
-      bundleService
+      browseService,
+      bundleService,
     );
   }
 
@@ -95,7 +93,7 @@ describe('ItemDataService', () => {
     });
 
     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 +104,7 @@ 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

@@ -1,6 +1,13 @@
-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';
@@ -16,12 +23,10 @@ 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';
-import { DeleteRequest, GetRequest, PostRequest, PutRequest} from './request.models';
+import { DeleteRequest, GetRequest, PostRequest, PutRequest } from './request.models';
 import { RequestService } from './request.service';
 import { PaginatedSearchOptions } from '../../shared/search/models/paginated-search-options.model';
 import { Bundle } from '../shared/bundle.model';
@@ -34,27 +39,41 @@ 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';
 
-@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 +319,85 @@ 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);
+  }
+
+  /**
+   * 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',
-    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 +8,17 @@ 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 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 +47,14 @@ 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 +62,6 @@ describe('ItemTemplateDataService', () => {
     }
   } as HALEndpointService;
   const notificationsService = {} as NotificationsService;
-  const http = {} as HttpClient;
   const comparator = {
     diff(first, second) {
       return [{}];
@@ -78,60 +77,61 @@ 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', () => {
-    it('should call commitUpdates on the item service implementation', () => {
-      spyOn(itemService, 'commitUpdates');
-      service.commitUpdates();
-      expect(itemService.commitUpdates).toHaveBeenCalled();
-    });
-  });
-
-  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/metadata-field-data.service.spec.ts

@@ -10,6 +10,7 @@ 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';
 
 describe('MetadataFieldDataService', () => {
   let metadataFieldService: MetadataFieldDataService;
@@ -33,16 +34,19 @@ 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(() => {

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

@@ -1,17 +1,11 @@
 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 +13,43 @@ 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';
 
 /**
  * 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 +120,80 @@ 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);
+  }
+
+  /**
+   * 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<MetadataField>[]): 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<MetadataField>[]): Observable<RemoteData<PaginatedList<MetadataField>>> {
+    return this.searchData.searchBy(searchMethod, options, useCachedVersionIfAvailable, reRequestOnStale, ...linksToFollow);
+  }
+
 }

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

@@ -24,14 +24,20 @@ 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(() => {

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

@@ -1,6 +1,4 @@
-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';
@@ -8,33 +6,45 @@ 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';
 
 /**
  * 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/persistent-identifier-data.service.ts

@@ -0,0 +1,28 @@
+/**
+ * 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 { BaseDataService } from './base/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';
+import { IdentifiableDataService } from './base/identifiable-data.service';
+import { FollowLinkConfig } from '../../shared/utils/follow-link-config.model';
+import { Observable } from 'rxjs';
+import { RemoteData } from './remote-data';
+import { DSpaceObject } from '../shared/dspace-object.model';
+
+export class PersistentIdentifierDataService extends IdentifiableDataService<DSpaceObject> {
+  constructor(
+    protected requestService: RequestService,
+    protected rdbService: RemoteDataBuildService,
+    protected objectCache: ObjectCacheService,
+    protected halService: HALEndpointService,
+  ) {
+    super('pid', requestService, rdbService, objectCache, halService);
+  }
+}

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

@@ -1,13 +1,8 @@
 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';
@@ -17,24 +12,26 @@ 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';
 
 @Injectable()
 @dataService(PROCESS)
-export class ProcessDataService extends DataService<Process> {
+export class ProcessDataService extends IdentifiableDataService<Process> implements FindAllData<Process> {
-  protected linkPath = 'processes';
+  private findAllData: FindAllData<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 comparator: DefaultChangeAnalyzer<Process>) {
+    super('processes', requestService, rdbService, objectCache, halService);
-    super();
+
+    this.findAllData = new FindAllDataImpl(this.linkPath, requestService, rdbService, objectCache, halService, this.responseMsToLive);
   }
 
   /**
@@ -55,4 +52,22 @@ export class ProcessDataService extends DataService<Process> {
     const href$ = this.getFilesEndpoint(processId);
     return this.bitstreamDataService.findAllByHref(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);
+  }
 }

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

@@ -1,18 +1,13 @@
 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';
 import { URLCombiner } from '../../url-combiner/url-combiner';
 import { RemoteData } from '../remote-data';
-import { MultipartPostRequest} from '../request.models';
+import { MultipartPostRequest } from '../request.models';
 import { RequestService } from '../request.service';
 import { Observable } from 'rxjs';
 import { dataService } from '../../cache/builders/build-decorators';
@@ -21,26 +16,29 @@ 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';
 
 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);
   }
 }

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

@@ -2,17 +2,14 @@ import { of as observableOf } from 'rxjs';
 import { getMockRemoteDataBuildService } from '../../shared/mocks/remote-data-build.service.mock';
 import { getMockRequestService } from '../../shared/mocks/request.service.mock';
 import { HALEndpointServiceStub } from '../../shared/testing/hal-endpoint-service.stub';
-import {
+import { createSuccessfulRemoteDataObject, createSuccessfulRemoteDataObject$ } from '../../shared/remote-data.utils';
-  createSuccessfulRemoteDataObject,
-  createSuccessfulRemoteDataObject$
-} from '../../shared/remote-data.utils';
-import { ObjectCacheService } from '../cache/object-cache.service';
 import { ItemType } from '../shared/item-relationships/item-type.model';
 import { RelationshipType } from '../shared/item-relationships/relationship-type.model';
 import { RelationshipTypeService } from './relationship-type.service';
 import { RequestService } from './request.service';
 import { createPaginatedList } from '../../shared/testing/utils.test';
 import { hasValueOperator } from '../../shared/empty.util';
+import { ObjectCacheService } from '../cache/object-cache.service';
 
 describe('RelationshipTypeService', () => {
   let service: RelationshipTypeService;
@@ -29,7 +26,6 @@ describe('RelationshipTypeService', () => {
   let relationshipType1;
   let relationshipType2;
 
-  let itemService;
   let buildList;
   let rdbService;
   let objectCache;
@@ -72,22 +68,14 @@ describe('RelationshipTypeService', () => {
       /* eslint-enable no-empty, @typescript-eslint/no-empty-function */
     }) as ObjectCacheService;
 
-    itemService = undefined;
-
   }
 
   function initTestService() {
     return new RelationshipTypeService(
-      itemService,
       requestService,
       rdbService,
-      null,
-      halService,
       objectCache,
-      null,
+      halService,
-      null,
-      null,
-      null
     );
   }
 

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

@@ -1,28 +1,22 @@
-import { HttpClient } from '@angular/common/http';
 import { Injectable } from '@angular/core';
-import { Store } from '@ngrx/store';
 import { combineLatest as observableCombineLatest, Observable } from 'rxjs';
 import { map, mergeMap, switchMap, toArray } from 'rxjs/operators';
-import { AppState } from '../../app.reducer';
 import { hasValue } from '../../shared/empty.util';
-import { NotificationsService } from '../../shared/notifications/notifications.service';
+import { followLink, FollowLinkConfig } from '../../shared/utils/follow-link-config.model';
-import { followLink } 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 { HALEndpointService } from '../shared/hal-endpoint.service';
 import { ItemType } from '../shared/item-relationships/item-type.model';
 import { RelationshipType } from '../shared/item-relationships/relationship-type.model';
 import { RELATIONSHIP_TYPE } from '../shared/item-relationships/relationship-type.resource-type';
-import { getFirstSucceededRemoteData, getFirstCompletedRemoteData, getRemoteDataPayload } from '../shared/operators';
+import { getFirstCompletedRemoteData, getFirstSucceededRemoteData, getRemoteDataPayload } from '../shared/operators';
-import { DataService } from './data.service';
-import { DefaultChangeAnalyzer } from './default-change-analyzer.service';
-import { ItemDataService } from './item-data.service';
 import { PaginatedList } from './paginated-list.model';
 import { RemoteData } from './remote-data';
 import { RequestService } from './request.service';
-import { CoreState } from '../core-state.model';
+import { BaseDataService } from './base/base-data.service';
-import { FollowLinkConfig } from '../../shared/utils/follow-link-config.model';
+import { FindAllDataImpl } from './base/find-all-data';
+import { SearchDataImpl } from './base/search-data';
+import { ObjectCacheService } from '../cache/object-cache.service';
 
 /**
  * Check if one side of a RelationshipType is the ItemType with the given label
@@ -38,20 +32,20 @@ const checkSide = (typeRd: RemoteData<ItemType>, label: string): boolean =>
  */
 @Injectable()
 @dataService(RELATIONSHIP_TYPE)
-export class RelationshipTypeService extends DataService<RelationshipType> {
+export class RelationshipTypeService extends BaseDataService<RelationshipType> {
-  protected linkPath = 'relationshiptypes';
+  private searchData: SearchDataImpl<RelationshipType>;
+  private findAllData: FindAllDataImpl<RelationshipType>;
 
-  constructor(protected itemService: ItemDataService,
+  constructor(
-              protected requestService: RequestService,
+    protected requestService: RequestService,
-              protected rdbService: RemoteDataBuildService,
+    protected rdbService: RemoteDataBuildService,
-              protected store: Store<CoreState>,
+    protected objectCache: ObjectCacheService,
-              protected halService: HALEndpointService,
+    protected halService: HALEndpointService,
-              protected objectCache: ObjectCacheService,
+  ) {
-              protected notificationsService: NotificationsService,
+    super('relationshiptypes', requestService, rdbService, objectCache, halService);
-              protected http: HttpClient,
+
-              protected comparator: DefaultChangeAnalyzer<RelationshipType>,
+    this.searchData = new SearchDataImpl(this.linkPath, requestService, rdbService, objectCache, halService, this.responseMsToLive);
-              protected appStore: Store<AppState>) {
+    this.findAllData = new FindAllDataImpl(this.linkPath, requestService, rdbService, objectCache, halService, this.responseMsToLive);
-    super();
   }
 
   /**
@@ -67,34 +61,34 @@ export class RelationshipTypeService extends DataService<RelationshipType> {
    */
   getRelationshipTypeByLabelAndTypes(relationshipTypeLabel: string, firstItemType: string, secondItemType: string): Observable<RelationshipType> {
     // Retrieve all relationship types from the server in a single page
-    return this.findAll({ currentPage: 1, elementsPerPage: 9999 }, true, true, followLink('leftType'), followLink('rightType'))
+    return this.findAllData.findAll({ currentPage: 1, elementsPerPage: 9999 }, true, true, followLink('leftType'), followLink('rightType'))
-      .pipe(
+               .pipe(
-        getFirstSucceededRemoteData(),
+                 getFirstSucceededRemoteData(),
-        // Emit each type in the page array separately
+                 // Emit each type in the page array separately
-        switchMap((typeListRD: RemoteData<PaginatedList<RelationshipType>>) => typeListRD.payload.page),
+                 switchMap((typeListRD: RemoteData<PaginatedList<RelationshipType>>) => typeListRD.payload.page),
-        // Check each type individually, to see if it matches the provided types
+                 // Check each type individually, to see if it matches the provided types
-        mergeMap((relationshipType: RelationshipType) => {
+                 mergeMap((relationshipType: RelationshipType) => {
-          if (relationshipType.leftwardType === relationshipTypeLabel) {
+                   if (relationshipType.leftwardType === relationshipTypeLabel) {
-            return this.checkType(relationshipType, firstItemType, secondItemType);
+                     return this.checkType(relationshipType, firstItemType, secondItemType);
-          } else if (relationshipType.rightwardType === relationshipTypeLabel) {
+                   } else if (relationshipType.rightwardType === relationshipTypeLabel) {
-            return this.checkType(relationshipType, secondItemType, firstItemType);
+                     return this.checkType(relationshipType, secondItemType, firstItemType);
-          } else {
+                   } else {
-            return [null];
+                     return [null];
-          }
+                   }
-        }),
+                 }),
-        // Wait for all types to be checked and emit once, with the results combined back into an
+                 // Wait for all types to be checked and emit once, with the results combined back into an
-        // array
+                 // array
-        toArray(),
+                 toArray(),
-        // Look for a match in the array and emit it if found, or null if one isn't found
+                 // Look for a match in the array and emit it if found, or null if one isn't found
-        map((types: RelationshipType[]) => {
+                 map((types: RelationshipType[]) => {
-          const match = types.find((type: RelationshipType) => hasValue(type));
+                   const match = types.find((type: RelationshipType) => hasValue(type));
-          if (hasValue(match)) {
+                   if (hasValue(match)) {
-            return match;
+                     return match;
-          } else {
+                   } else {
-            return null;
+                     return null;
-          }
+                   }
-        })
+                 }),
-      );
+               );
   }
 
   /**
@@ -127,27 +121,29 @@ export class RelationshipTypeService extends DataService<RelationshipType> {
    * Returns an observable of the given RelationshipType if it matches, null if it doesn't
    *
    * @param type            The RelationshipType to check
+   * @param useCachedVersionIfAvailable
+   * @param reRequestOnStale
+   * @param linksToFollow
    */
-  searchByEntityType(type: string,useCachedVersionIfAvailable = true, reRequestOnStale = true, ...linksToFollow: FollowLinkConfig<RelationshipType>[]): Observable<PaginatedList<RelationshipType>> {
+  searchByEntityType(type: string, useCachedVersionIfAvailable = true, reRequestOnStale = true, ...linksToFollow: FollowLinkConfig<RelationshipType>[]): Observable<PaginatedList<RelationshipType>> {
-
+    return this.searchData.searchBy(
-    return this.searchBy(
       'byEntityType',
       {
         searchParams: [
           {
             fieldName: 'type',
-            fieldValue: type
+            fieldValue: type,
           },
           {
             fieldName: 'size',
-            fieldValue: 100
+            fieldValue: 100,
           },
-        ]
+        ],
-      }, useCachedVersionIfAvailable,reRequestOnStale,...linksToFollow).pipe(
+      }, useCachedVersionIfAvailable, reRequestOnStale, ...linksToFollow,
+    ).pipe(
       getFirstSucceededRemoteData(),
       getRemoteDataPayload(),
     ) as Observable<PaginatedList<RelationshipType>>;
   }
 
-
 }

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

@@ -6,7 +6,7 @@ import { Relationship } from '../shared/item-relationships/relationship.model';
 import { Item } from '../shared/item.model';
 import { PageInfo } from '../shared/page-info.model';
 import { buildPaginatedList } from './paginated-list.model';
-import { DeleteRequest} from './request.models';
+import { DeleteRequest } from './request.models';
 import { RelationshipService } from './relationship.service';
 import { RequestService } from './request.service';
 import { HALEndpointServiceStub } from '../../shared/testing/hal-endpoint-service.stub';
@@ -123,15 +123,11 @@ describe('RelationshipService', () => {
 
   function initTestService() {
     return new RelationshipService(
-      itemService,
       requestService,
       rdbService,
-      null,
       halService,
       objectCache,
-      null,
+      itemService,
-      null,
-      null,
       null,
       jasmine.createSpy('paginatedRelationsToItems').and.returnValue((v) => v),
     );

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

@@ -1,4 +1,4 @@
-import { HttpClient, HttpHeaders } from '@angular/common/http';
+import { HttpHeaders } from '@angular/common/http';
 import { Inject, Injectable } from '@angular/core';
 import { MemoizedSelector, select, Store } from '@ngrx/store';
 import { combineLatest as observableCombineLatest, Observable } from 'rxjs';
@@ -15,7 +15,6 @@ import {
   SetNameVariantAction
 } from '../../shared/form/builder/ds-dynamic-form-ui/relation-lookup-modal/name-variant.actions';
 import { NameVariantListState } from '../../shared/form/builder/ds-dynamic-form-ui/relation-lookup-modal/name-variant.reducer';
-import { NotificationsService } from '../../shared/notifications/notifications.service';
 import { followLink, FollowLinkConfig } from '../../shared/utils/follow-link-config.model';
 import { dataService } from '../cache/builders/build-decorators';
 import { RemoteDataBuildService } from '../cache/builders/remote-data-build.service';
@@ -33,19 +32,19 @@ import {
   getFirstSucceededRemoteDataPayload,
   getRemoteDataPayload
 } from '../shared/operators';
-import { DataService } from './data.service';
-import { DefaultChangeAnalyzer } from './default-change-analyzer.service';
 import { ItemDataService } from './item-data.service';
 import { PaginatedList } from './paginated-list.model';
 import { RemoteData } from './remote-data';
-import { DeleteRequest, PostRequest} from './request.models';
+import { DeleteRequest, PostRequest } from './request.models';
 import { RequestService } from './request.service';
 import { NoContent } from '../shared/NoContent.model';
 import { RequestEntryState } from './request-entry-state.model';
 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 { SearchData, SearchDataImpl } from './base/search-data';
+import { PutData, PutDataImpl } from './base/put-data';
+import { IdentifiableDataService } from './base/identifiable-data.service';
 
 const relationshipListsStateSelector = (state: AppState) => state.relationshipLists;
 
@@ -75,22 +74,23 @@ const compareItemsByUUID = (itemCheck: Item) =>
  */
 @Injectable()
 @dataService(RELATIONSHIP)
-export class RelationshipService extends DataService<Relationship> {
+export class RelationshipService extends IdentifiableDataService<Relationship> implements SearchData<Relationship> {
-  protected linkPath = 'relationships';
+  private searchData: SearchData<Relationship>;
-  protected responseMsToLive = 15 * 60 * 1000;
+  private putData: PutData<Relationship>;
 
-  constructor(protected itemService: ItemDataService,
+  constructor(
-              protected requestService: RequestService,
+    protected requestService: RequestService,
-              protected rdbService: RemoteDataBuildService,
+    protected rdbService: RemoteDataBuildService,
-              protected store: Store<CoreState>,
+    protected halService: HALEndpointService,
-              protected halService: HALEndpointService,
+    protected objectCache: ObjectCacheService,
-              protected objectCache: ObjectCacheService,
+    protected itemService: ItemDataService,
-              protected notificationsService: NotificationsService,
+    protected appStore: Store<AppState>,
-              protected http: HttpClient,
+    @Inject(PAGINATED_RELATIONS_TO_ITEMS_OPERATOR) private paginatedRelationsToItems: (thisId: string) => (source: Observable<RemoteData<PaginatedList<Relationship>>>) => Observable<RemoteData<PaginatedList<Item>>>,
-              protected comparator: DefaultChangeAnalyzer<Relationship>,
+  ) {
-              protected appStore: Store<AppState>,
+    super('relationships', requestService, rdbService, objectCache, halService, 15 * 60 * 1000);
-              @Inject(PAGINATED_RELATIONS_TO_ITEMS_OPERATOR) private paginatedRelationsToItems: (thisId: string) => (source: Observable<RemoteData<PaginatedList<Relationship>>>) => Observable<RemoteData<PaginatedList<Item>>>) {
+
-    super();
+    this.searchData = new SearchDataImpl(this.linkPath, requestService, rdbService, objectCache, halService, this.responseMsToLive);
+    this.putData = new PutDataImpl(this.linkPath, requestService, rdbService, objectCache, halService, this.responseMsToLive);
   }
 
   /**
@@ -99,13 +99,15 @@ export class RelationshipService extends DataService<Relationship> {
    */
   getRelationshipEndpoint(uuid: string) {
     return this.getBrowseEndpoint().pipe(
-      map((href: string) => `${href}/${uuid}`)
+      map((href: string) => `${href}/${uuid}`),
     );
   }
 
   /**
    * Send a delete request for a relationship by ID
-   * @param id
+   * @param id                    the ID of the relationship to delete
+   * @param copyVirtualMetadata   whether to copy this relationship's virtual metadata to the related Items
+   *                              accepted values: none, all, left, right, configured
    */
   deleteRelationship(id: string, copyVirtualMetadata: string): Observable<RemoteData<NoContent>> {
     return this.getRelationshipEndpoint(id).pipe(
@@ -469,7 +471,7 @@ export class RelationshipService extends DataService<Relationship> {
    * @param object the {@link Relationship} to update
    */
   update(object: Relationship): Observable<RemoteData<Relationship>> {
-    return this.put(object);
+    return this.putData.put(object);
   }
 
   /**
@@ -513,7 +515,7 @@ export class RelationshipService extends DataService<Relationship> {
       searchParams.push(
         {
           fieldName: 'relatedItem',
-          fieldValue: itemId
+          fieldValue: itemId,
         },
       );
     });
@@ -521,8 +523,31 @@ export class RelationshipService extends DataService<Relationship> {
     return this.searchBy(
       'byItemsAndType',
       {
-        searchParams: searchParams
+        searchParams: searchParams,
-      }) as Observable<RemoteData<PaginatedList<Relationship>>>;
+      },
+    ) as Observable<RemoteData<PaginatedList<Relationship>>>;
 
   }
+
+  /**
+   * 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<Relationship>[]): Observable<RemoteData<PaginatedList<Relationship>>> {
+    return this.searchData.searchBy(searchMethod, options, useCachedVersionIfAvailable, reRequestOnStale, ...linksToFollow);
+  }
+
+  getSearchByHref(searchMethod: string, options: FindListOptions, ...linksToFollow: FollowLinkConfig<Relationship>[]): Observable<string> {
+    return this.searchData.getSearchByHref(searchMethod, options, ...linksToFollow);
+  }
 }

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

@@ -12,19 +12,20 @@ describe('RootDataService', () => {
   let halService: HALEndpointService;
   let restService;
   let rootEndpoint;
+  let findByHrefSpy;
 
   beforeEach(() => {
     rootEndpoint = 'root-endpoint';
     halService = jasmine.createSpyObj('halService', {
-      getRootHref: rootEndpoint
+      getRootHref: rootEndpoint,
     });
     restService = jasmine.createSpyObj('halService', {
-      get: jasmine.createSpy('get')
+      get: jasmine.createSpy('get'),
-    });
-    service = new RootDataService(null, null, null, null, halService, null, null, null, restService);
-    (service as any).dataService = jasmine.createSpyObj('dataService', {
-      findByHref: createSuccessfulRemoteDataObject$({})
     });
+    service = new RootDataService(null, null, null, halService, restService);
+
+    findByHrefSpy = spyOn(service as any, 'findByHref');
+    findByHrefSpy.and.returnValue(createSuccessfulRemoteDataObject$({}));
   });
 
   describe('findRoot', () => {
@@ -36,7 +37,7 @@ describe('RootDataService', () => {
 
     it('should call findByHref using the root endpoint', (done) => {
       result$.subscribe(() => {
-        expect((service as any).dataService.findByHref).toHaveBeenCalledWith(rootEndpoint, true, true);
+        expect(findByHrefSpy).toHaveBeenCalledWith(rootEndpoint, true, true);
         done();
       });
     });

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

@@ -1,70 +1,33 @@
-/* eslint-disable max-classes-per-file */
-import { DataService } from './data.service';
 import { Root } from './root.model';
 import { Injectable } from '@angular/core';
 import { ROOT } from './root.resource-type';
 import { dataService } from '../cache/builders/build-decorators';
 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 { Observable, of as observableOf } from 'rxjs';
 import { RemoteData } from './remote-data';
 import { FollowLinkConfig } from '../../shared/utils/follow-link-config.model';
-import { PaginatedList } from './paginated-list.model';
-import { CoreState } from '../core-state.model';
-import { FindListOptions } from './find-list-options.model';
 import { DspaceRestService } from '../dspace-rest/dspace-rest.service';
 import { RawRestResponse } from '../dspace-rest/raw-rest-response.model';
 import { catchError, map } from 'rxjs/operators';
-
+import { BaseDataService } from './base/base-data.service';
-
+import { ObjectCacheService } from '../cache/object-cache.service';
-/**
- * A private DataService implementation to delegate specific methods to.
- */
-class DataServiceImpl extends DataService<Root> {
-  protected linkPath = '';
-  protected responseMsToLive = 6 * 60 * 60 * 1000;
-
-  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<Root>) {
-    super();
-  }
-}
 
 /**
  * A service to retrieve the {@link Root} object from the REST API.
  */
 @Injectable()
 @dataService(ROOT)
-export class RootDataService {
+export class RootDataService extends BaseDataService<Root> {
-  /**
-   * 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 restService: DspaceRestService,
-    protected http: HttpClient,
+  ) {
-    protected comparator: DefaultChangeAnalyzer<Root>,
+    super('', requestService, rdbService, objectCache, halService, 6 * 60 * 60 * 1000);
-    protected restService: DspaceRestService) {
-    this.dataService = new DataServiceImpl(requestService, rdbService, null, objectCache, halService, notificationsService, http, comparator);
   }
 
   /**
@@ -90,38 +53,7 @@ export class RootDataService {
    *                                    {@link HALLink}s should be automatically resolved
    */
   findRoot(useCachedVersionIfAvailable = true, reRequestOnStale = true, ...linksToFollow: FollowLinkConfig<Root>[]): Observable<RemoteData<Root>> {
-    return this.dataService.findByHref(this.halService.getRootHref(), useCachedVersionIfAvailable, reRequestOnStale, ...linksToFollow);
+    return this.findByHref(this.halService.getRootHref(), 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 | Observable<string>, useCachedVersionIfAvailable = true, reRequestOnStale = true, ...linksToFollow: FollowLinkConfig<Root>[]): Observable<RemoteData<Root>> {
-    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 | Observable<string>, findListOptions: FindListOptions = {}, useCachedVersionIfAvailable = true, reRequestOnStale = true, ...linksToFollow: FollowLinkConfig<Root>[]): Observable<RemoteData<PaginatedList<Root>>> {
-    return this.dataService.findAllByHref(href, findListOptions, useCachedVersionIfAvailable, reRequestOnStale, ...linksToFollow);
   }
 
   /**

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

@@ -4,14 +4,10 @@ import { RequestService } from './request.service';
 import { RemoteDataBuildService } from '../cache/builders/remote-data-build.service';
 import { ObjectCacheService } from '../cache/object-cache.service';
 import { Site } from '../shared/site.model';
-import { Store } from '@ngrx/store';
-import { NotificationsService } from '../../shared/notifications/notifications.service';
-import { HttpClient } from '@angular/common/http';
 import { HALEndpointService } from '../shared/hal-endpoint.service';
 import { TestScheduler } from 'rxjs/testing';
 import { createSuccessfulRemoteDataObject } from '../../shared/remote-data.utils';
 import { createPaginatedList } from '../../shared/testing/utils.test';
-import { CoreState } from '../core-state.model';
 import { FindListOptions } from './find-list-options.model';
 
 describe('SiteDataService', () => {
@@ -47,21 +43,13 @@ describe('SiteDataService', () => {
       })
     });
 
-    const store = {} as Store<CoreState>;
     objectCache = {} as ObjectCacheService;
-    const notificationsService = {} as NotificationsService;
-    const http = {} as HttpClient;
-    const comparator = {} as any;
 
     service = new SiteDataService(
       requestService,
       rdbService,
-      store,
       objectCache,
       halService,
-      notificationsService,
-      http,
-      comparator
     );
   });
 

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

@@ -1,42 +1,38 @@
-import { HttpClient } from '@angular/common/http';
 import { Injectable } from '@angular/core';
-import { Store } from '@ngrx/store';
 import { Observable } from 'rxjs';
 import { map } 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 { HALEndpointService } from '../shared/hal-endpoint.service';
 import { getFirstSucceededRemoteData } from '../shared/operators';
 import { Site } from '../shared/site.model';
 import { SITE } from '../shared/site.resource-type';
-import { DataService } from './data.service';
-import { DSOChangeAnalyzer } from './dso-change-analyzer.service';
 import { PaginatedList } from './paginated-list.model';
 import { RemoteData } from './remote-data';
 import { RequestService } from './request.service';
-import { CoreState } from '../core-state.model';
+import { BaseDataService } from './base/base-data.service';
+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 { ObjectCacheService } from '../cache/object-cache.service';
 
 /**
  * Service responsible for handling requests related to the Site object
  */
 @Injectable()
 @dataService(SITE)
-export class SiteDataService extends DataService<Site> {
+export class SiteDataService extends BaseDataService<Site> implements FindAllData<Site> {
-  protected linkPath = 'sites';
+  private findAllData: FindAllData<Site>;
 
   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<Site>,
   ) {
-    super();
+    super('sites', requestService, rdbService, objectCache, halService);
+
+    this.findAllData = new FindAllDataImpl(this.linkPath, requestService, rdbService, objectCache, halService, this.responseMsToLive);
   }
 
   /**
@@ -46,7 +42,25 @@ export class SiteDataService extends DataService<Site> {
     return this.findAll().pipe(
       getFirstSucceededRemoteData(),
       map((remoteData: RemoteData<PaginatedList<Site>>) => remoteData.payload),
-      map((list: PaginatedList<Site>) => list.page[0])
+      map((list: PaginatedList<Site>) => list.page[0]),
     );
   }
+
+  /**
+   * 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<Site>[]): Observable<RemoteData<PaginatedList<Site>>> {
+    return this.findAllData.findAll(options, useCachedVersionIfAvailable, reRequestOnStale, ...linksToFollow);
+  }
 }

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

@@ -1,18 +1,12 @@
-import { HttpClient } from '@angular/common/http';
 import { of as observableOf } from 'rxjs';
 import { TestScheduler } from 'rxjs/testing';
-
-import { NotificationsService } from '../../shared/notifications/notifications.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 { RequestService } from './request.service';
-import { PageInfo } from '../shared/page-info.model';
 import { createSuccessfulRemoteDataObject, createSuccessfulRemoteDataObject$ } from '../../shared/remote-data.utils';
 import { HrefOnlyDataService } from './href-only-data.service';
 import { getMockHrefOnlyDataService } from '../../shared/mocks/href-only-data.service.mock';
-
-import { Store } from '@ngrx/store';
 import { RestResponse } from '../cache/response.models';
 import { cold, getTestScheduler, hot } from 'jasmine-marbles';
 import { Item } from '../shared/item.model';
@@ -20,10 +14,8 @@ import { VersionDataService } from './version-data.service';
 import { Version } from '../shared/version.model';
 import { VersionHistory } from '../shared/version-history.model';
 import { followLink } from '../../shared/utils/follow-link-config.model';
-import { CoreState } from '../core-state.model';
 import { RequestEntry } from './request-entry.model';
 
-
 describe('VersionDataService test', () => {
   let scheduler: TestScheduler;
   let service: VersionDataService;
@@ -80,29 +72,17 @@ describe('VersionDataService test', () => {
   const mockVersionRD = createSuccessfulRemoteDataObject(mockVersion);
 
   const endpointURL = `https://rest.api/rest/api/versioning/versions`;
-  const findByIdRequestURL = `https://rest.api/rest/api/versioning/versions/${mockVersion.id}`;
-  const findByIdRequestURL$ = observableOf(findByIdRequestURL);
-
   const requestUUID = '8b3c613a-5a4b-438b-9686-be1d5b4a1c5a';
 
   objectCache = {} as ObjectCacheService;
-  const notificationsService = {} as NotificationsService;
-  const http = {} as HttpClient;
-  const comparator = {} as any;
   const comparatorEntry = {} as any;
-  const store = {} as Store<CoreState>;
-  const pageInfo = new PageInfo();
-
   function initTestService() {
     hrefOnlyDataService = getMockHrefOnlyDataService();
     return new VersionDataService(
       requestService,
       rdbService,
-      store,
       objectCache,
       halService,
-      notificationsService,
-      http,
       comparatorEntry
     );
   }
@@ -134,8 +114,7 @@ describe('VersionDataService test', () => {
 
       service = initTestService();
 
-      spyOn((service as any), 'findByHref').and.callThrough();
+      spyOn((service as any), 'findById').and.callThrough();
-      spyOn((service as any), 'getIDHrefObs').and.returnValue(findByIdRequestURL$);
     });
 
     afterEach(() => {
@@ -147,7 +126,7 @@ describe('VersionDataService test', () => {
         scheduler.schedule(() => service.getHistoryFromVersion(mockVersion, true, true));
         scheduler.flush();
 
-        expect((service as any).findByHref).toHaveBeenCalledWith(findByIdRequestURL$, true, true, followLink('versionhistory'));
+        expect((service as any).findById).toHaveBeenCalledWith(mockVersion.id, true, true, followLink('versionhistory'));
       });
 
       it('should return a VersionHistory', () => {

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

@@ -1,14 +1,9 @@
 import { Injectable } from '@angular/core';
-import { DataService } from './data.service';
 import { Version } from '../shared/version.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 { DefaultChangeAnalyzer } from './default-change-analyzer.service';
 import { EMPTY, Observable } from 'rxjs';
 import { dataService } from '../cache/builders/build-decorators';
 import { VERSION } from '../shared/version.resource-type';
@@ -17,26 +12,30 @@ import { followLink } from '../../shared/utils/follow-link-config.model';
 import { getFirstSucceededRemoteDataPayload } from '../shared/operators';
 import { map, switchMap } from 'rxjs/operators';
 import { isNotEmpty } from '../../shared/empty.util';
-import { CoreState } from '../core-state.model';
+import { RemoteData } from './remote-data';
+import { PatchData, PatchDataImpl } from './base/patch-data';
+import { RestRequestMethod } from './rest-request-method';
+import { DefaultChangeAnalyzer } from './default-change-analyzer.service';
+import { IdentifiableDataService } from './base/identifiable-data.service';
 
 /**
  * Service responsible for handling requests related to the Version object
  */
 @Injectable()
 @dataService(VERSION)
-export class VersionDataService extends DataService<Version> {
+export class VersionDataService extends IdentifiableDataService<Version> implements PatchData<Version> {
-  protected linkPath = 'versions';
+  private patchData: PatchData<Version>;
 
   constructor(
     protected requestService: RequestService,
     protected rdbService: RemoteDataBuildService,
-    protected store: Store<CoreState>,
     protected objectCache: ObjectCacheService,
     protected halService: HALEndpointService,
-    protected notificationsService: NotificationsService,
+    protected comparator: DefaultChangeAnalyzer<Version>,
-    protected http: HttpClient,
+  ) {
-    protected comparator: DefaultChangeAnalyzer<Version>) {
+    super('versions', requestService, rdbService, objectCache, halService);
-    super();
+
+    this.patchData = new PatchDataImpl(this.linkPath, requestService, rdbService, objectCache, halService, comparator, this.responseMsToLive, this.constructIdEndpoint);
   }
 
   /**
@@ -65,4 +64,29 @@ export class VersionDataService extends DataService<Version> {
     );
   }
 
+  /**
+   * 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: Version, operations: []): Observable<RemoteData<Version>> {
+    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: Version): Observable<RemoteData<Version>> {
+    return this.patchData.update(object);
+  }
+
+  /**
+   * 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);
+  }
 }

src/app/core/data/version-history-data.service.spec.ts

@@ -102,7 +102,7 @@ describe('VersionHistoryDataService', () => {
       buildFromRequestUUID: jasmine.createSpy('buildFromRequestUUID'),
     });
     objectCache = jasmine.createSpyObj('objectCache', {
-      remove: jasmine.createSpy('remove')
+      remove: jasmine.createSpy('remove'),
     });
     versionService = jasmine.createSpyObj('objectCache', {
       findByHref: jasmine.createSpy('findByHref'),
@@ -112,7 +112,13 @@ describe('VersionHistoryDataService', () => {
     halService = new HALEndpointServiceStub(url);
     notificationsService = new NotificationsServiceStub();
 
-    service = new VersionHistoryDataService(requestService, rdbService, null, objectCache, halService, notificationsService, versionService, null, null);
+    service = new VersionHistoryDataService(
+      requestService,
+      rdbService,
+      objectCache,
+      halService,
+      versionService,
+    );
   }
 
   beforeEach(() => {

src/app/core/data/version-history-data.service.ts

@@ -1,14 +1,10 @@
-import { DataService } from './data.service';
 import { VersionHistory } from '../shared/version-history.model';
 import { Injectable } from '@angular/core';
 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 { HttpHeaders } from '@angular/common/http';
-import { HttpClient, HttpHeaders } from '@angular/common/http';
-import { DefaultChangeAnalyzer } from './default-change-analyzer.service';
 import { PostRequest } from './request.models';
 import { Observable, of } from 'rxjs';
 import { PaginatedSearchOptions } from '../../shared/search/models/paginated-search-options.model';
@@ -21,40 +17,31 @@ import { VERSION_HISTORY } from '../shared/version-history.resource-type';
 import { followLink, FollowLinkConfig } from '../../shared/utils/follow-link-config.model';
 import { VersionDataService } from './version-data.service';
 import { HttpOptions } from '../dspace-rest/dspace-rest.service';
-import {
+import { getAllSucceededRemoteData, getFirstCompletedRemoteData, getFirstSucceededRemoteDataPayload, getRemoteDataPayload } from '../shared/operators';
-  getAllSucceededRemoteData,
-  getFirstCompletedRemoteData,
-  getFirstSucceededRemoteDataPayload,
-  getRemoteDataPayload
-} from '../shared/operators';
 import { PaginationComponentOptions } from '../../shared/pagination/pagination-component-options.model';
 import { hasValueOperator } from '../../shared/empty.util';
 import { Item } from '../shared/item.model';
-import { CoreState } from '../core-state.model';
 import { FindListOptions } from './find-list-options.model';
 import { sendRequest } from '../shared/request.operators';
 import { RestRequest } from './rest-request.model';
+import { IdentifiableDataService } from './base/identifiable-data.service';
 
 /**
  * Service responsible for handling requests related to the VersionHistory object
  */
 @Injectable()
 @dataService(VERSION_HISTORY)
-export class VersionHistoryDataService extends DataService<VersionHistory> {
+export class VersionHistoryDataService extends IdentifiableDataService<VersionHistory> {
-  protected linkPath = 'versionhistories';
   protected versionsEndpoint = 'versions';
 
   constructor(
     protected requestService: RequestService,
     protected rdbService: RemoteDataBuildService,
-    protected store: Store<CoreState>,
     protected objectCache: ObjectCacheService,
     protected halService: HALEndpointService,
-    protected notificationsService: NotificationsService,
     protected versionDataService: VersionDataService,
-    protected http: HttpClient,
+  ) {
-    protected comparator: DefaultChangeAnalyzer<VersionHistory>) {
+    super('versionhistories', requestService, rdbService, objectCache, halService);
-    super();
   }
 
   /**

src/app/core/data/workflow-action-data.service.ts

@@ -1,41 +1,27 @@
-import { DataService } from './data.service';
 import { WorkflowAction } from '../tasks/models/workflow-action-object.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 { DefaultChangeAnalyzer } from './default-change-analyzer.service';
-import { Observable } from 'rxjs';
 import { Injectable } from '@angular/core';
 import { dataService } from '../cache/builders/build-decorators';
 import { WORKFLOW_ACTION } from '../tasks/models/workflow-action-object.resource-type';
-import { CoreState } from '../core-state.model';
+import { BaseDataService } from './base/base-data.service';
-import { FindListOptions } from './find-list-options.model';
 
 /**
  * A service responsible for fetching/sending data from/to the REST API on the workflowactions endpoint
  */
 @Injectable()
 @dataService(WORKFLOW_ACTION)
-export class WorkflowActionDataService extends DataService<WorkflowAction> {
+export class WorkflowActionDataService extends BaseDataService<WorkflowAction> {
   protected linkPath = 'workflowactions';
 
   constructor(
     protected requestService: RequestService,
     protected rdbService: RemoteDataBuildService,
-    protected store: Store<CoreState>,
     protected objectCache: ObjectCacheService,
     protected halService: HALEndpointService,
-    protected notificationsService: NotificationsService,
+  ) {
-    protected http: HttpClient,
+    super('workflowactions', requestService, rdbService, objectCache, halService);
-    protected comparator: DefaultChangeAnalyzer<WorkflowAction>) {
-    super();
-  }
-
-  getBrowseEndpoint(options: FindListOptions, linkPath?: string): Observable<string> {
-    return this.halService.getEndpoint(this.linkPath);
   }
 }

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

@@ -13,7 +13,7 @@ import {
 } from '../../access-control/epeople-registry/epeople-registry.actions';
 import { RequestParam } from '../cache/models/request-param.model';
 import { ChangeAnalyzer } from '../data/change-analyzer';
-import { DeleteRequest, PatchRequest, PostRequest } from '../data/request.models';
+import { PatchRequest, PostRequest } from '../data/request.models';
 import { RequestService } from '../data/request.service';
 import { HALEndpointService } from '../shared/hal-endpoint.service';
 import { Item } from '../shared/item.model';
@@ -47,12 +47,11 @@ describe('EPersonDataService', () => {
     return new EPersonDataService(
       requestService,
       rdbService,
-      store,
       null,
       halService,
+      new DummyChangeAnalyzer() as any,
       null,
-      null,
+      store,
-      new DummyChangeAnalyzer() as any
     );
   }
 

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

@@ -1,35 +1,36 @@
-import { HttpClient } from '@angular/common/http';
 import { Injectable } from '@angular/core';
 import { createSelector, select, Store } from '@ngrx/store';
 import { Operation } from 'fast-json-patch';
 import { Observable } from 'rxjs';
 import { find, map, take } from 'rxjs/operators';
-import {
+import { EPeopleRegistryCancelEPersonAction, EPeopleRegistryEditEPersonAction } from '../../access-control/epeople-registry/epeople-registry.actions';
-  EPeopleRegistryCancelEPersonAction,
-  EPeopleRegistryEditEPersonAction
-} from '../../access-control/epeople-registry/epeople-registry.actions';
 import { EPeopleRegistryState } from '../../access-control/epeople-registry/epeople-registry.reducers';
 import { AppState } from '../../app.reducer';
-import { hasValue, hasNoValue } from '../../shared/empty.util';
+import { hasNoValue, 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 { RequestParam } from '../cache/models/request-param.model';
 import { ObjectCacheService } from '../cache/object-cache.service';
-import { DataService } from '../data/data.service';
 import { DSOChangeAnalyzer } from '../data/dso-change-analyzer.service';
-import { PaginatedList, buildPaginatedList } from '../data/paginated-list.model';
+import { buildPaginatedList, PaginatedList } from '../data/paginated-list.model';
 import { RemoteData } from '../data/remote-data';
-import { PatchRequest, PostRequest, } from '../data/request.models';
+import { PatchRequest, PostRequest } from '../data/request.models';
 import { RequestService } from '../data/request.service';
 import { HALEndpointService } from '../shared/hal-endpoint.service';
-import { getRemoteDataPayload, getFirstSucceededRemoteData, } from '../shared/operators';
+import { getFirstSucceededRemoteData, getRemoteDataPayload } from '../shared/operators';
 import { EPerson } from './models/eperson.model';
 import { EPERSON } from './models/eperson.resource-type';
 import { NoContent } from '../shared/NoContent.model';
 import { PageInfo } from '../shared/page-info.model';
 import { FindListOptions } from '../data/find-list-options.model';
+import { CreateData, CreateDataImpl } from '../data/base/create-data';
+import { IdentifiableDataService } from '../data/base/identifiable-data.service';
+import { SearchData, SearchDataImpl } from '../data/base/search-data';
+import { PatchData, PatchDataImpl } from '../data/base/patch-data';
+import { DeleteData, DeleteDataImpl } from '../data/base/delete-data';
+import { RestRequestMethod } from '../data/rest-request-method';
 
 const ePeopleRegistryStateSelector = (state: AppState) => state.epeopleRegistry;
 const editEPersonSelector = createSelector(ePeopleRegistryStateSelector, (ePeopleRegistryState: EPeopleRegistryState) => ePeopleRegistryState.editEPerson);
@@ -39,23 +40,30 @@ const editEPersonSelector = createSelector(ePeopleRegistryStateSelector, (ePeopl
  */
 @Injectable()
 @dataService(EPERSON)
-export class EPersonDataService extends DataService<EPerson> {
+export class EPersonDataService extends IdentifiableDataService<EPerson> implements CreateData<EPerson>, SearchData<EPerson>, PatchData<EPerson>, DeleteData<EPerson> {
-
-  protected linkPath = 'epersons';
   protected searchByEmailPath = 'byEmail';
   protected searchByMetadataPath = 'byMetadata';
 
+  private createData: CreateData<EPerson>;
+  private searchData: SearchData<EPerson>;
+  private patchData: PatchData<EPerson>;
+  private deleteData: DeleteData<EPerson>;
+
   constructor(
     protected requestService: RequestService,
     protected rdbService: RemoteDataBuildService,
-    protected store: Store<any>,
     protected objectCache: ObjectCacheService,
     protected halService: HALEndpointService,
+    protected comparator: DSOChangeAnalyzer<EPerson>,
     protected notificationsService: NotificationsService,
-    protected http: HttpClient,
+    protected store: Store<any>,
-    protected comparator: DSOChangeAnalyzer<EPerson>
   ) {
-    super();
+    super('epersons', 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.patchData = new PatchDataImpl<EPerson>(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);
   }
 
   /**
@@ -326,4 +334,90 @@ export class EPersonDataService extends DataService<EPerson> {
     return this.rdbService.buildFromRequestUUID(requestId);
   }
 
+
+  /**
+   * 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: EPerson, ...params: RequestParam[]): Observable<RemoteData<EPerson>> {
+    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
+   */
+  searchBy(searchMethod: string, options?: FindListOptions, useCachedVersionIfAvailable?: boolean, reRequestOnStale?: boolean, ...linksToFollow: FollowLinkConfig<EPerson>[]): Observable<RemoteData<PaginatedList<EPerson>>> {
+    return this.searchData.searchBy(searchMethod, options, 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<EPerson>[]): Observable<string> {
+    return this.searchData.getSearchByHref(searchMethod, options, ...linksToFollow);
+  }
+
+  /**
+   * 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: EPerson): Observable<Operation[]> {
+    return this.patchData.createPatchFromCache(object);
+  }
+
+  patch(object: EPerson, operations: Operation[]): Observable<RemoteData<EPerson>> {
+    return this.patchData.patch(object, operations);
+  }
+
+  update(object: EPerson): Observable<RemoteData<EPerson>> {
+    return this.patchData.update(object);
+  }
+
+  commitUpdates(method?: RestRequestMethod): void {
+    this.patchData.commitUpdates(method);
+  }
+
+  /**
+   * 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/eperson/group-data.service.spec.ts

@@ -65,15 +65,14 @@ describe('GroupDataService', () => {
 
   function initTestService() {
     return new GroupDataService(
+      requestService,
+      rdbService,
+      null,
+      halService,
       new DummyChangeAnalyzer() as any,
       null,
       null,
-      requestService,
-      rdbService,
       store,
-      null,
-      halService,
-      null,
     );
   }
 

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

@@ -1,4 +1,4 @@
-import { HttpClient, HttpHeaders } from '@angular/common/http';
+import { HttpHeaders } from '@angular/common/http';
 import { Injectable } from '@angular/core';
 
 import { createSelector, select, Store } from '@ngrx/store';
@@ -15,7 +15,6 @@ 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 { ObjectCacheService } from '../cache/object-cache.service';
-import { DataService } from '../data/data.service';
 import { DSOChangeAnalyzer } from '../data/dso-change-analyzer.service';
 import { PaginatedList } from '../data/paginated-list.model';
 import { RemoteData } from '../data/remote-data';
@@ -34,6 +33,13 @@ import { Community } from '../shared/community.model';
 import { Collection } from '../shared/collection.model';
 import { NoContent } from '../shared/NoContent.model';
 import { FindListOptions } from '../data/find-list-options.model';
+import { CreateData, CreateDataImpl } from '../data/base/create-data';
+import { IdentifiableDataService } from '../data/base/identifiable-data.service';
+import { SearchData, SearchDataImpl } from '../data/base/search-data';
+import { PatchData, PatchDataImpl } from '../data/base/patch-data';
+import { DeleteData, DeleteDataImpl } from '../data/base/delete-data';
+import { Operation } from 'fast-json-patch';
+import { RestRequestMethod } from '../data/rest-request-method';
 
 const groupRegistryStateSelector = (state: AppState) => state.groupRegistry;
 const editGroupSelector = createSelector(groupRegistryStateSelector, (groupRegistryState: GroupRegistryState) => groupRegistryState.editGroup);
@@ -43,24 +49,32 @@ const editGroupSelector = createSelector(groupRegistryStateSelector, (groupRegis
  */
 @Injectable()
 @dataService(GROUP)
-export class GroupDataService extends DataService<Group> {
+export class GroupDataService extends IdentifiableDataService<Group> {
-  protected linkPath = 'groups';
   protected browseEndpoint = '';
   public ePersonsEndpoint = 'epersons';
   public subgroupsEndpoint = 'subgroups';
 
+  private createData: CreateData<Group>;
+  private searchData: SearchData<Group>;
+  private patchData: PatchData<Group>;
+  private deleteData: DeleteData<Group>;
+
   constructor(
-    protected comparator: DSOChangeAnalyzer<Group>,
-    protected http: HttpClient,
-    protected notificationsService: NotificationsService,
     protected requestService: RequestService,
     protected rdbService: RemoteDataBuildService,
-    protected store: Store<any>,
     protected objectCache: ObjectCacheService,
     protected halService: HALEndpointService,
+    protected comparator: DSOChangeAnalyzer<Group>,
+    protected notificationsService: NotificationsService,
     protected nameService: DSONameService,
+    protected store: Store<any>,
   ) {
-    super();
+    super('groups', 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.patchData = new PatchDataImpl<Group>(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);
   }
 
   /**
@@ -322,4 +336,42 @@ export class GroupDataService extends DataService<Group> {
 
     return responseRD$;
   }
+
+
+  public create(object: Group, ...params: RequestParam[]): Observable<RemoteData<Group>> {
+    return this.createData.create(object, ...params);
+  }
+
+  //
+  searchBy(searchMethod: string, options?: FindListOptions, useCachedVersionIfAvailable?: boolean, reRequestOnStale?: boolean, ...linksToFollow: FollowLinkConfig<Group>[]): Observable<RemoteData<PaginatedList<Group>>> {
+    return this.searchData.searchBy(searchMethod, options, useCachedVersionIfAvailable, reRequestOnStale, ...linksToFollow);
+  }
+
+  getSearchByHref(searchMethod: string, options?: FindListOptions, ...linksToFollow: FollowLinkConfig<Group>[]): Observable<string> {
+    return this.searchData.getSearchByHref(searchMethod, options, ...linksToFollow);
+  }
+
+  public createPatchFromCache(object: Group): Observable<Operation[]> {
+    return this.patchData.createPatchFromCache(object);
+  }
+
+  patch(object: Group, operations: Operation[]): Observable<RemoteData<Group>> {
+    return this.patchData.patch(object, operations);
+  }
+
+  update(object: Group): Observable<RemoteData<Group>> {
+    return this.patchData.update(object);
+  }
+
+  commitUpdates(method?: RestRequestMethod): void {
+    this.patchData.commitUpdates(method);
+  }
+
+  delete(objectId: string, copyVirtualMetadata?: string[]): Observable<RemoteData<NoContent>> {
+    return this.deleteData.delete(objectId, copyVirtualMetadata);
+  }
+
+  public deleteByHref(href: string, copyVirtualMetadata?: string[]): Observable<RemoteData<NoContent>> {
+    return this.deleteData.deleteByHref(href, copyVirtualMetadata);
+  }
 }

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

@@ -5,9 +5,7 @@ import { HALEndpointServiceStub } from '../../shared/testing/hal-endpoint-servic
 import { RemoteDataBuildService } from '../cache/builders/remote-data-build.service';
 import { getMockRequestService } from '../../shared/mocks/request.service.mock';
 import { NotificationsService } from '../../shared/notifications/notifications.service';
-import { HttpClient } from '@angular/common/http';
 import { Store } from '@ngrx/store';
-import { DSOChangeAnalyzer } from '../data/dso-change-analyzer.service';
 import { Feedback } from './models/feedback.model';
 import { CoreState } from '../core-state.model';
 
@@ -17,8 +15,6 @@ describe('FeedbackDataService', () => {
   let halService;
   let rdbService;
   let notificationsService;
-  let http;
-  let comparator;
   let objectCache;
   let store;
   let item;
@@ -44,8 +40,6 @@ describe('FeedbackDataService', () => {
     halService = new HALEndpointServiceStub('url') as any;
     rdbService = {} as RemoteDataBuildService;
     notificationsService = {} as NotificationsService;
-    http = {} as HttpClient;
-    comparator = new DSOChangeAnalyzer() as any;
     objectCache = {
 
       addPatch: () => {
@@ -63,8 +57,6 @@ describe('FeedbackDataService', () => {
       objectCache,
       halService,
       notificationsService,
-      http,
-      comparator,
     );
   }
 

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

@@ -1,6 +1,5 @@
 import { Injectable } from '@angular/core';
 import { Observable } from 'rxjs';
-import { DataService } from '../data/data.service';
 import { Feedback } from './models/feedback.model';
 import { FEEDBACK } from './models/feedback.resource-type';
 import { dataService } from '../cache/builders/build-decorators';
@@ -10,17 +9,19 @@ 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 '../data/dso-change-analyzer.service';
 import { getFirstSucceededRemoteData, getRemoteDataPayload } from '../shared/operators';
+import { IdentifiableDataService } from '../data/base/identifiable-data.service';
+import { RemoteData } from '../data/remote-data';
+import { RequestParam } from '../cache/models/request-param.model';
+import { CreateData, CreateDataImpl } from '../data/base/create-data';
 
 /**
  * Service for checking and managing the feedback
  */
 @Injectable()
 @dataService(FEEDBACK)
-export class FeedbackDataService extends DataService<Feedback> {
+export class FeedbackDataService extends IdentifiableDataService<Feedback> implements CreateData<Feedback> {
-  protected linkPath = 'feedbacks';
+  private createData: CreateDataImpl<Feedback>;
 
   constructor(
     protected requestService: RequestService,
@@ -29,10 +30,10 @@ export class FeedbackDataService extends DataService<Feedback> {
     protected objectCache: ObjectCacheService,
     protected halService: HALEndpointService,
     protected notificationsService: NotificationsService,
-    protected http: HttpClient,
-    protected comparator: DSOChangeAnalyzer<Feedback>,
   ) {
-    super();
+    super('feedbacks', requestService, rdbService, objectCache, halService);
+
+    this.createData = new CreateDataImpl(this.linkPath, requestService, rdbService, objectCache, halService, notificationsService, this.responseMsToLive);
   }
 
   /**
@@ -46,4 +47,14 @@ export class FeedbackDataService extends DataService<Feedback> {
     );
   }
 
+
+  /**
+   * 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: Feedback, ...params: RequestParam[]): Observable<RemoteData<Feedback>> {
+    return this.createData.create(object, ...params);
+  }
 }

src/app/core/orcid/orcid-auth.service.spec.ts

@@ -165,7 +165,8 @@ describe('OrcidAuthService', () => {
     routerStub = new RouterMock();
     researcherProfileService = jasmine.createSpyObj('ResearcherProfileService', {
       findById: jasmine.createSpy('findById'),
-      updateByOrcidOperations: jasmine.createSpy('updateByOrcidOperations')
+      patch: jasmine.createSpy('patch'),
+      updateByOrcidOperations: jasmine.createSpy('updateByOrcidOperations'),
     });
     configurationDataService = jasmine.createSpyObj('configurationDataService', {
       findByPropertyName: jasmine.createSpy('findByPropertyName')
@@ -237,7 +238,7 @@ describe('OrcidAuthService', () => {
   describe('linkOrcidByItem', () => {
     beforeEach(() => {
       scheduler = getTestScheduler();
-      researcherProfileService.updateByOrcidOperations.and.returnValue(createSuccessfulRemoteDataObject$(researcherProfilePatched));
+      researcherProfileService.patch.and.returnValue(createSuccessfulRemoteDataObject$(researcherProfilePatched));
       researcherProfileService.findById.and.returnValue(createSuccessfulRemoteDataObject$(researcherProfile));
     });
 
@@ -251,14 +252,14 @@ describe('OrcidAuthService', () => {
       scheduler.schedule(() => service.linkOrcidByItem(mockItemUnlinkedToOrcid, 'test-code').subscribe());
       scheduler.flush();
 
-      expect(researcherProfileService.updateByOrcidOperations).toHaveBeenCalledWith(researcherProfile, operations);
+      expect(researcherProfileService.patch).toHaveBeenCalledWith(researcherProfile, operations);
     });
   });
 
   describe('unlinkOrcidByItem', () => {
     beforeEach(() => {
       scheduler = getTestScheduler();
-      researcherProfileService.updateByOrcidOperations.and.returnValue(createSuccessfulRemoteDataObject$(researcherProfilePatched));
+      researcherProfileService.patch.and.returnValue(createSuccessfulRemoteDataObject$(researcherProfilePatched));
       researcherProfileService.findById.and.returnValue(createSuccessfulRemoteDataObject$(researcherProfile));
     });
 
@@ -271,7 +272,7 @@ describe('OrcidAuthService', () => {
       scheduler.schedule(() => service.unlinkOrcidByItem(mockItemLinkedToOrcid).subscribe());
       scheduler.flush();
 
-      expect(researcherProfileService.updateByOrcidOperations).toHaveBeenCalledWith(researcherProfile, operations);
+      expect(researcherProfileService.patch).toHaveBeenCalledWith(researcherProfile, operations);
     });
   });
 

src/app/core/orcid/orcid-auth.service.ts

@@ -77,7 +77,7 @@ export class OrcidAuthService {
 
     return this.researcherProfileService.findById(person.firstMetadata('dspace.object.owner').authority).pipe(
       getFirstCompletedRemoteData(),
-      switchMap((profileRD) => this.researcherProfileService.updateByOrcidOperations(profileRD.payload, operations))
+      switchMap((profileRD) => this.researcherProfileService.patch(profileRD.payload, operations)),
     );
   }
 
@@ -94,7 +94,7 @@ export class OrcidAuthService {
 
     return this.researcherProfileService.findById(person.firstMetadata('dspace.object.owner').authority).pipe(
       getFirstCompletedRemoteData(),
-      switchMap((profileRD) => this.researcherProfileService.updateByOrcidOperations(profileRD.payload, operations))
+      switchMap((profileRD) => this.researcherProfileService.patch(profileRD.payload, operations)),
     );
   }
 

src/app/core/orcid/orcid-history-data.service.ts

@@ -1,16 +1,10 @@
-// eslint-disable-next-line max-classes-per-file
+import { HttpHeaders } from '@angular/common/http';
-import { HttpClient, HttpHeaders } from '@angular/common/http';
 import { Injectable } from '@angular/core';
-import { Store } from '@ngrx/store';
 import { Observable } from 'rxjs';
 import { map, switchMap } 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 { DataService } from '../data/data.service';
-import { DefaultChangeAnalyzer } from '../data/default-change-analyzer.service';
-import { ItemDataService } from '../data/item-data.service';
 import { RemoteData } from '../data/remote-data';
 import { PostRequest } from '../data/request.models';
 import { RequestService } from '../data/request.service';
@@ -19,58 +13,24 @@ import { OrcidHistory } from './model/orcid-history.model';
 import { ORCID_HISTORY } from './model/orcid-history.resource-type';
 import { OrcidQueue } from './model/orcid-queue.model';
 import { HttpOptions } from '../dspace-rest/dspace-rest.service';
-import { CoreState } from '../core-state.model';
 import { RestRequest } from '../data/rest-request.model';
 import { sendRequest } from '../shared/request.operators';
-import { FollowLinkConfig } from '../../shared/utils/follow-link-config.model';
+import { IdentifiableDataService } from '../data/base/identifiable-data.service';
-import { FindListOptions } from '../data/find-list-options.model';
-import { PaginatedList } from '../data/paginated-list.model';
-
-/**
- * A private DataService implementation to delegate specific methods to.
- */
-class OrcidHistoryServiceImpl extends DataService<OrcidHistory> {
-  public linkPath = 'orcidhistories';
-
-  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<OrcidHistory>) {
-    super();
-  }
-
-}
 
 /**
  * A service that provides methods to make REST requests with Orcid History endpoint.
  */
 @Injectable()
 @dataService(ORCID_HISTORY)
-export class OrcidHistoryDataService {
+export class OrcidHistoryDataService extends IdentifiableDataService<OrcidHistory> {
-
-  dataService: OrcidHistoryServiceImpl;
-
-  responseMsToLive: number = 10 * 1000;
 
   constructor(
-      protected requestService: RequestService,
+    protected requestService: RequestService,
-      protected rdbService: RemoteDataBuildService,
+    protected rdbService: RemoteDataBuildService,
-      protected store: Store<CoreState>,
+    protected objectCache: ObjectCacheService,
-      protected objectCache: ObjectCacheService,
+    protected halService: HALEndpointService,
-      protected halService: HALEndpointService,
+  ) {
-      protected notificationsService: NotificationsService,
+    super('orcidhistories', requestService, rdbService, objectCache, halService, 10 * 1000);
-      protected http: HttpClient,
-      protected comparator: DefaultChangeAnalyzer<OrcidHistory>,
-      protected itemService: ItemDataService ) {
-
-          this.dataService = new OrcidHistoryServiceImpl(requestService, rdbService, store, objectCache, halService,
-              notificationsService, http, comparator);
-
   }
 
   sendToORCID(orcidQueue: OrcidQueue): Observable<RemoteData<OrcidHistory>> {
@@ -87,40 +47,4 @@ export class OrcidHistoryDataService {
       switchMap((request: RestRequest) => this.rdbService.buildFromRequestUUID(request.uuid)  as Observable<RemoteData<OrcidHistory>>)
     );
   }
-
-  getEndpoint(): Observable<string> {
-    return this.halService.getEndpoint(this.dataService.linkPath);
-  }
-
-  /**
-   * 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<OrcidHistory>[]): Observable<RemoteData<OrcidHistory>> {
-    return this.dataService.findById(id, useCachedVersionIfAvailable, reRequestOnStale, ...linksToFollow);
-  }
-
-  /**
-   * Returns a list of observables of {@link RemoteData} of {@link OrcidHistory}s, based on an href, with a list of {@link FollowLinkConfig},
-   * to automatically resolve {@link HALLink}s of the {@link OrcidHistory}
-   * @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<OrcidHistory>[]): Observable<RemoteData<PaginatedList<OrcidHistory>>> {
-    return this.dataService.findAllByHref(href, findListOptions, useCachedVersionIfAvailable, reRequestOnStale, ...linksToFollow);
-  }
-
 }

src/app/core/orcid/orcid-queue.service.ts

@@ -1,75 +1,42 @@
-// eslint-disable-next-line max-classes-per-file
-import { DataService } from '../data/data.service';
 import { OrcidQueue } from './model/orcid-queue.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 { Injectable } from '@angular/core';
 import { dataService } from '../cache/builders/build-decorators';
 import { ORCID_QUEUE } from './model/orcid-queue.resource-type';
-import { ItemDataService } from '../data/item-data.service';
 import { Observable } from 'rxjs';
 import { RemoteData } from '../data/remote-data';
 import { PaginatedList } from '../data/paginated-list.model';
 import { RequestParam } from '../cache/models/request-param.model';
 import { PaginationComponentOptions } from '../../shared/pagination/pagination-component-options.model';
 import { NoContent } from '../shared/NoContent.model';
-import { ConfigurationDataService } from '../data/configuration-data.service';
+import { DeleteData, DeleteDataImpl } from '../data/base/delete-data';
-import { Router } from '@angular/router';
+import { SearchData, SearchDataImpl } from '../data/base/search-data';
-import { CoreState } from '../core-state.model';
+import { IdentifiableDataService } from '../data/base/identifiable-data.service';
-
-/**
- * A private DataService implementation to delegate specific methods to.
- */
-class OrcidQueueServiceImpl extends DataService<OrcidQueue> {
-  public linkPath = 'orcidqueues';
-
-  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<OrcidQueue>) {
-    super();
-  }
-
-}
 
 /**
  * A service that provides methods to make REST requests with Orcid Queue endpoint.
  */
 @Injectable()
 @dataService(ORCID_QUEUE)
-export class OrcidQueueService {
+export class OrcidQueueService extends IdentifiableDataService<OrcidQueue> {
-
+  private searchData: SearchData<OrcidQueue>;
-  dataService: OrcidQueueServiceImpl;
+  private deleteData: DeleteData<OrcidQueue>;
-
-  responseMsToLive: number = 10 * 1000;
 
   constructor(
-      protected requestService: RequestService,
+    protected requestService: RequestService,
-      protected rdbService: RemoteDataBuildService,
+    protected rdbService: RemoteDataBuildService,
-      protected store: Store<CoreState>,
+    protected objectCache: ObjectCacheService,
-      protected objectCache: ObjectCacheService,
+    protected halService: HALEndpointService,
-      protected halService: HALEndpointService,
+    protected notificationsService: NotificationsService,
-      protected notificationsService: NotificationsService,
+  ) {
-      protected http: HttpClient,
+    super('orcidqueues', requestService, rdbService, objectCache, halService, 10 * 1000);
-      protected comparator: DefaultChangeAnalyzer<OrcidQueue>,
-      protected configurationService: ConfigurationDataService,
-      protected router: Router,
-      protected itemService: ItemDataService ) {
-
-          this.dataService = new OrcidQueueServiceImpl(requestService, rdbService, store, objectCache, halService,
-              notificationsService, http, comparator);
 
+    this.searchData = new SearchDataImpl(this.linkPath, requestService, rdbService, objectCache, halService, this.responseMsToLive);
+    this.deleteData = new DeleteDataImpl(this.linkPath, requestService, rdbService, objectCache, halService, notificationsService, this.responseMsToLive, this.constructIdEndpoint);
   }
 
   /**
@@ -82,13 +49,13 @@ export class OrcidQueueService {
    * @returns { OrcidQueue }
    */
   searchByProfileItemId(itemId: string, paginationOptions: PaginationComponentOptions, useCachedVersionIfAvailable = true, reRequestOnStale = true): Observable<RemoteData<PaginatedList<OrcidQueue>>> {
-    return this.dataService.searchBy('findByProfileItem', {
+    return this.searchData.searchBy('findByProfileItem', {
         searchParams: [new RequestParam('profileItemId', itemId)],
         elementsPerPage: paginationOptions.pageSize,
-        currentPage: paginationOptions.currentPage
+        currentPage: paginationOptions.currentPage,
       },
       useCachedVersionIfAvailable,
-      reRequestOnStale
+      reRequestOnStale,
     );
   }
 
@@ -97,14 +64,14 @@ export class OrcidQueueService {
    * @returns { NoContent }
    */
   deleteById(orcidQueueId: number): Observable<RemoteData<NoContent>> {
-    return this.dataService.delete(orcidQueueId.toString());
+    return this.deleteData.delete(orcidQueueId.toString());
   }
 
   /**
    * This method will set linkPath to stale
    */
   clearFindByProfileItemRequests() {
-    this.requestService.setStaleByHrefSubstring(this.dataService.linkPath + '/search/findByProfileItem');
+    this.requestService.setStaleByHrefSubstring(this.linkPath + '/search/findByProfileItem');
   }
 
 }

src/app/core/profile/researcher-profile.service.spec.ts

@@ -253,46 +253,27 @@ describe('ResearcherProfileService', () => {
       objectCache,
       halService,
       notificationsService,
-      http,
       routerStub,
       comparator,
-      itemService
+      itemService,
     );
     serviceAsAny = service;
 
-    spyOn((service as any).dataService, 'create').and.callThrough();
+    spyOn((service as any), 'findById').and.callThrough();
-    spyOn((service as any).dataService, 'delete').and.callThrough();
+    spyOn((service as any), 'findByHref').and.callThrough();
-    spyOn((service as any).dataService, 'update').and.callThrough();
+    spyOn((service as any), 'getLinkPath').and.returnValue(observableOf(endpointURL));
-    spyOn((service as any).dataService, 'findById').and.callThrough();
+    spyOn((service as any).createData, 'create').and.callThrough();
-    spyOn((service as any).dataService, 'findByHref').and.callThrough();
+    spyOn((service as any).patchData, 'update').and.callThrough();
-    spyOn((service as any).dataService, 'searchBy').and.callThrough();
+    spyOn((service as any).searchData, 'searchBy').and.callThrough();
-    spyOn((service as any).dataService, 'getLinkPath').and.returnValue(observableOf(endpointURL));
+    spyOn((service as any).deleteData, 'delete').and.callThrough();
-
-  });
-
-  describe('findById', () => {
-    it('should proxy the call to dataservice.findById with eperson UUID', () => {
-      scheduler.schedule(() => service.findById(researcherProfileId));
-      scheduler.flush();
-
-      expect((service as any).dataService.findById).toHaveBeenCalledWith(researcherProfileId, true, true);
-    });
-
-    it('should return a ResearcherProfile object with the given id', () => {
-      const result = service.findById(researcherProfileId);
-      const expected = cold('a|', {
-        a: researcherProfileRD
-      });
-      expect(result).toBeObservable(expected);
-    });
   });
 
   describe('create', () => {
-    it('should proxy the call to dataservice.create with eperson UUID', () => {
+    it('should proxy the call to createData.create with eperson UUID', () => {
       scheduler.schedule(() => service.create());
       scheduler.flush();
 
-      expect((service as any).dataService.create).toHaveBeenCalled();
+      expect((service as any).createData.create).toHaveBeenCalled();
     });
 
     it('should return the RemoteData<ResearcherProfile> created', () => {
@@ -305,11 +286,11 @@ describe('ResearcherProfileService', () => {
   });
 
   describe('delete', () => {
-    it('should proxy the call to dataservice.delete', () => {
+    it('should proxy the call to deleteData.delete', () => {
-      scheduler.schedule(() => service.delete(researcherProfile));
+      scheduler.schedule(() => service.delete(researcherProfile.id));
       scheduler.flush();
 
-      expect((service as any).dataService.delete).toHaveBeenCalledWith(researcherProfile.id);
+      expect((service as any).deleteData.delete).toHaveBeenCalledWith(researcherProfile.id, undefined);
     });
   });
 
@@ -360,34 +341,33 @@ describe('ResearcherProfileService', () => {
   });
 
   describe('setVisibility', () => {
-    let patchSpy;
     beforeEach(() => {
-      spyOn((service as any).dataService, 'patch').and.returnValue(createSuccessfulRemoteDataObject$(researcherProfilePatched));
+      spyOn((service as any).patchData, 'patch').and.returnValue(createSuccessfulRemoteDataObject$(researcherProfilePatched));
-      spyOn((service as any), 'findById').and.returnValue(createSuccessfulRemoteDataObject$(researcherProfilePatched));
+      (service.findById as jasmine.Spy).and.returnValue(createSuccessfulRemoteDataObject$(researcherProfilePatched));
     });
 
-    it('should proxy the call to dataservice.patch', () => {
+    it('should proxy the call to patchData.patch', () => {
       const replaceOperation: ReplaceOperation<boolean> = {
         path: '/visible',
         op: 'replace',
-        value: true
+        value: true,
       };
 
       scheduler.schedule(() => service.setVisibility(researcherProfile, true));
       scheduler.flush();
 
-      expect((service as any).dataService.patch).toHaveBeenCalledWith(researcherProfile, [replaceOperation]);
+      expect((service as any).patchData.patch).toHaveBeenCalledWith(researcherProfile, [replaceOperation]);
     });
   });
 
   describe('createFromExternalSource', () => {
 
     beforeEach(() => {
-      spyOn((service as any).dataService, 'patch').and.returnValue(createSuccessfulRemoteDataObject$(researcherProfilePatched));
+      spyOn((service as any).patchData, 'patch').and.returnValue(createSuccessfulRemoteDataObject$(researcherProfilePatched));
-      spyOn((service as any), 'findById').and.returnValue(createSuccessfulRemoteDataObject$(researcherProfilePatched));
+      (service.findById as jasmine.Spy).and.returnValue(createSuccessfulRemoteDataObject$(researcherProfilePatched));
     });
 
-    it('should proxy the call to dataservice.patch', () => {
+    it('should proxy the call to patchData.patch', () => {
       const options: HttpOptions = Object.create({});
       let headers = new HttpHeaders();
       headers = headers.append('Content-Type', 'text/uri-list');
@@ -406,14 +386,14 @@ describe('ResearcherProfileService', () => {
   describe('updateByOrcidOperations', () => {
     beforeEach(() => {
       scheduler = getTestScheduler();
-      spyOn((service as any).dataService, 'patch').and.returnValue(createSuccessfulRemoteDataObject$(researcherProfilePatched));
+      spyOn((service as any).patchData, 'patch').and.returnValue(createSuccessfulRemoteDataObject$(researcherProfilePatched));
     });
 
     it('should call patch method properly', () => {
-      scheduler.schedule(() => service.updateByOrcidOperations(researcherProfile, []).subscribe());
+      scheduler.schedule(() => service.patch(researcherProfile, []).subscribe());
       scheduler.flush();
 
-      expect((service as any).dataService.patch).toHaveBeenCalledWith(researcherProfile, []);
+      expect((service as any).patchData.patch).toHaveBeenCalledWith(researcherProfile, []);
     });
   });
 });

src/app/core/profile/researcher-profile.service.ts

@@ -1,9 +1,7 @@
-/* eslint-disable max-classes-per-file */
+import { HttpHeaders } from '@angular/common/http';
-import { HttpClient, HttpHeaders } from '@angular/common/http';
 import { Injectable } from '@angular/core';
 import { Router } from '@angular/router';
 
-import { Store } from '@ngrx/store';
 import { Operation, ReplaceOperation } from 'fast-json-patch';
 import { Observable } from 'rxjs';
 import { find, map } from 'rxjs/operators';
@@ -11,54 +9,41 @@ import { NotificationsService } from '../../shared/notifications/notifications.s
 import { dataService } from '../cache/builders/build-decorators';
 import { RemoteDataBuildService } from '../cache/builders/remote-data-build.service';
 import { ObjectCacheService } from '../cache/object-cache.service';
-import { DataService } from '../data/data.service';
 import { DefaultChangeAnalyzer } from '../data/default-change-analyzer.service';
 import { ItemDataService } from '../data/item-data.service';
 import { RemoteData } from '../data/remote-data';
 import { RequestService } from '../data/request.service';
 import { HALEndpointService } from '../shared/hal-endpoint.service';
 import { NoContent } from '../shared/NoContent.model';
-import { getAllCompletedRemoteData, getFirstCompletedRemoteData } from '../shared/operators';
+import { getFirstCompletedRemoteData } from '../shared/operators';
 import { ResearcherProfile } from './model/researcher-profile.model';
 import { RESEARCHER_PROFILE } from './model/researcher-profile.resource-type';
 import { HttpOptions } from '../dspace-rest/dspace-rest.service';
 import { PostRequest } from '../data/request.models';
 import { hasValue, isEmpty } from '../../shared/empty.util';
-import { CoreState } from '../core-state.model';
 import { followLink, FollowLinkConfig } from '../../shared/utils/follow-link-config.model';
 import { Item } from '../shared/item.model';
 import { createFailedRemoteDataObject$ } from '../../shared/remote-data.utils';
-
+import { IdentifiableDataService } from '../data/base/identifiable-data.service';
-/**
+import { CreateData, CreateDataImpl } from '../data/base/create-data';
- * A private DataService implementation to delegate specific methods to.
+import { SearchData, SearchDataImpl } from '../data/base/search-data';
- */
+import { PatchData, PatchDataImpl } from '../data/base/patch-data';
-class ResearcherProfileServiceImpl extends DataService<ResearcherProfile> {
+import { DeleteData, DeleteDataImpl } from '../data/base/delete-data';
-  protected linkPath = 'profiles';
+import { RestRequestMethod } from '../data/rest-request-method';
-
+import { RequestParam } from '../cache/models/request-param.model';
-  constructor(
+import { FindListOptions } from '../data/find-list-options.model';
-    protected requestService: RequestService,
+import { PaginatedList } from '../data/paginated-list.model';
-    protected rdbService: RemoteDataBuildService,
-    protected store: Store<CoreState>,
-    protected objectCache: ObjectCacheService,
-    protected halService: HALEndpointService,
-    protected notificationsService: NotificationsService,
-    protected http: HttpClient,
-    protected comparator: DefaultChangeAnalyzer<ResearcherProfile>) {
-    super();
-  }
-
-}
 
 /**
  * A service that provides methods to make REST requests with researcher profile endpoint.
  */
 @Injectable()
 @dataService(RESEARCHER_PROFILE)
-export class ResearcherProfileService {
+export class ResearcherProfileService extends IdentifiableDataService<ResearcherProfile> implements CreateData<ResearcherProfile>, SearchData<ResearcherProfile>, PatchData<ResearcherProfile>, DeleteData<ResearcherProfile> {
-
+  private createData: CreateDataImpl<ResearcherProfile>;
-  protected dataService: ResearcherProfileServiceImpl;
+  private searchData: SearchDataImpl<ResearcherProfile>;
-
+  private patchData: PatchDataImpl<ResearcherProfile>;
-  protected responseMsToLive: number = 10 * 1000;
+  private deleteData: DeleteDataImpl<ResearcherProfile>;
 
   constructor(
     protected requestService: RequestService,
@@ -66,50 +51,16 @@ export class ResearcherProfileService {
     protected objectCache: ObjectCacheService,
     protected halService: HALEndpointService,
     protected notificationsService: NotificationsService,
-    protected http: HttpClient,
     protected router: Router,
     protected comparator: DefaultChangeAnalyzer<ResearcherProfile>,
-    protected itemService: ItemDataService) {
+    protected itemService: ItemDataService,
+  ) {
+    super('profiles', requestService, rdbService, objectCache, halService, 10 * 1000);
 
-    this.dataService = new ResearcherProfileServiceImpl(requestService, rdbService, null, objectCache, halService,
+    this.createData = new CreateDataImpl(this.linkPath, requestService, rdbService, objectCache, halService, notificationsService, this.responseMsToLive);
-      notificationsService, http, comparator);
+    this.patchData = new PatchDataImpl<ResearcherProfile>(this.linkPath, requestService, rdbService, objectCache, halService, comparator, this.responseMsToLive, this.constructIdEndpoint);
-
+    this.searchData = new SearchDataImpl(this.linkPath, requestService, rdbService, objectCache, halService, this.responseMsToLive);
-  }
+    this.deleteData = new DeleteDataImpl(this.linkPath, requestService, rdbService, objectCache, halService, notificationsService, this.responseMsToLive, this.constructIdEndpoint);
-
-  /**
-   * Find the researcher profile with the given uuid.
-   *
-   * @param uuid the profile uuid
-   * @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 findById(uuid: string, useCachedVersionIfAvailable = true, reRequestOnStale = true, ...linksToFollow: FollowLinkConfig<ResearcherProfile>[]): Observable<RemoteData<ResearcherProfile>> {
-    return this.dataService.findById(uuid, useCachedVersionIfAvailable, reRequestOnStale, ...linksToFollow).pipe(
-      getAllCompletedRemoteData(),
-    );
-  }
-
-  /**
-   * Create a new researcher profile for the current user.
-   */
-  public create(): Observable<RemoteData<ResearcherProfile>> {
-    return this.dataService.create(new ResearcherProfile());
-  }
-
-  /**
-   * Delete a researcher profile.
-   *
-   * @param researcherProfile the profile to delete
-   */
-  public delete(researcherProfile: ResearcherProfile): Observable<boolean> {
-    return this.dataService.delete(researcherProfile.id).pipe(
-      getFirstCompletedRemoteData(),
-      map((response: RemoteData<NoContent>) => response.isSuccess)
-    );
   }
 
   /**
@@ -152,7 +103,7 @@ export class ResearcherProfileService {
       value: visible
     };
 
-    return this.dataService.patch(researcherProfile, [replaceOperation]);
+    return this.patch(researcherProfile, [replaceOperation]);
   }
 
   /**
@@ -166,11 +117,11 @@ export class ResearcherProfileService {
     options.headers = headers;
 
     const requestId = this.requestService.generateRequestId();
-    const href$ = this.halService.getEndpoint(this.dataService.getLinkPath());
+    const href$ = this.halService.getEndpoint(this.getLinkPath());
 
     href$.pipe(
       find((href: string) => hasValue(href)),
-      map((href: string) => this.dataService.buildHrefWithParams(href, [], followLink('item')))
+      map((href: string) => this.buildHrefWithParams(href, [], followLink('item'))),
     ).subscribe((endpoint: string) => {
       const request = new PostRequest(requestId, endpoint, sourceUri, options);
       this.requestService.send(request);
@@ -179,16 +130,85 @@ export class ResearcherProfileService {
     return this.rdbService.buildFromRequestUUID(requestId, followLink('item'));
   }
 
+
   /**
-   * Update researcher profile by patch orcid operation
+   * Create a new object on the server, and store the response in the object cache
    *
-   * @param researcherProfile
+   * @param object    The object to create
-   * @param operations
+   * @param params    Array with additional params to combine with query string
    */
-  public updateByOrcidOperations(researcherProfile: ResearcherProfile, operations: Operation[]): Observable<RemoteData<ResearcherProfile>> {
+  public create(object?: ResearcherProfile, ...params: RequestParam[]): Observable<RemoteData<ResearcherProfile>> {
-    return this.dataService.patch(researcherProfile, operations);
+    if (isEmpty(object)) {
+      object = new ResearcherProfile();
+    }
+    return this.createData.create(object, ...params);
   }
 
+  searchBy(searchMethod: string, options?: FindListOptions, useCachedVersionIfAvailable?: boolean, reRequestOnStale?: boolean, ...linksToFollow: FollowLinkConfig<ResearcherProfile>[]): Observable<RemoteData<PaginatedList<ResearcherProfile>>> {
+    return this.searchData.searchBy(searchMethod, options, useCachedVersionIfAvailable, reRequestOnStale, ...linksToFollow);
+  }
 
+  getSearchByHref?(searchMethod: string, options?: FindListOptions, ...linksToFollow: FollowLinkConfig<ResearcherProfile>[]): Observable<string> {
+    return this.searchData.getSearchByHref(searchMethod, options, ...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);
+  }
+
+  /**
+   * 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: ResearcherProfile): Observable<Operation[]> {
+    return this.patchData.createPatchFromCache(object);
+  }
+
+  /**
+   * 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: ResearcherProfile, operations: Operation[]): Observable<RemoteData<ResearcherProfile>> {
+    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: ResearcherProfile): Observable<RemoteData<ResearcherProfile>> {
+    return this.patchData.update(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/resource-policy/resource-policy.service.spec.ts

@@ -131,7 +131,6 @@ describe('ResourcePolicyService', () => {
     });
     objectCache = {} as ObjectCacheService;
     const notificationsService = {} as NotificationsService;
-    const http = {} as HttpClient;
     const comparator = {} as any;
 
     service = new ResourcePolicyService(
@@ -140,42 +139,41 @@ describe('ResourcePolicyService', () => {
       objectCache,
       halService,
       notificationsService,
-      http,
       comparator,
       ePersonService,
-      groupService
+      groupService,
     );
 
-    spyOn((service as any).dataService, 'create').and.callThrough();
+    spyOn((service as any).createData, 'create').and.callThrough();
-    spyOn((service as any).dataService, 'delete').and.callThrough();
+    spyOn((service as any).deleteData, 'delete').and.callThrough();
-    spyOn((service as any).dataService, 'update').and.callThrough();
+    spyOn((service as any).patchData, 'update').and.callThrough();
-    spyOn((service as any).dataService, 'findById').and.callThrough();
+    spyOn((service as any), 'findById').and.callThrough();
-    spyOn((service as any).dataService, 'findByHref').and.callThrough();
+    spyOn((service as any), 'findByHref').and.callThrough();
-    spyOn((service as any).dataService, 'searchBy').and.callThrough();
+    spyOn((service as any).searchData, 'searchBy').and.callThrough();
-    spyOn((service as any).dataService, 'getSearchByHref').and.returnValue(observableOf(requestURL));
+    spyOn((service as any).searchData, 'getSearchByHref').and.returnValue(observableOf(requestURL));
   });
 
   describe('create', () => {
-    it('should proxy the call to dataservice.create with eperson UUID', () => {
+    it('should proxy the call to createData.create with eperson UUID', () => {
       scheduler.schedule(() => service.create(resourcePolicy, resourceUUID, epersonUUID));
       const params = [
         new RequestParam('resource', resourceUUID),
-        new RequestParam('eperson', epersonUUID)
+        new RequestParam('eperson', epersonUUID),
       ];
       scheduler.flush();
 
-      expect((service as any).dataService.create).toHaveBeenCalledWith(resourcePolicy, ...params);
+      expect((service as any).createData.create).toHaveBeenCalledWith(resourcePolicy, ...params);
     });
 
-    it('should proxy the call to dataservice.create with group UUID', () => {
+    it('should proxy the call to createData.create with group UUID', () => {
       scheduler.schedule(() => service.create(resourcePolicy, resourceUUID, null, groupUUID));
       const params = [
         new RequestParam('resource', resourceUUID),
-        new RequestParam('group', groupUUID)
+        new RequestParam('group', groupUUID),
       ];
       scheduler.flush();
 
-      expect((service as any).dataService.create).toHaveBeenCalledWith(resourcePolicy, ...params);
+      expect((service as any).createData.create).toHaveBeenCalledWith(resourcePolicy, ...params);
     });
 
     it('should return a RemoteData<ResourcePolicy> for the object with the given id', () => {
@@ -188,31 +186,24 @@ describe('ResourcePolicyService', () => {
   });
 
   describe('delete', () => {
-    it('should proxy the call to dataservice.create', () => {
+    it('should proxy the call to deleteData.delete', () => {
       scheduler.schedule(() => service.delete(resourcePolicyId));
       scheduler.flush();
 
-      expect((service as any).dataService.delete).toHaveBeenCalledWith(resourcePolicyId);
+      expect((service as any).deleteData.delete).toHaveBeenCalledWith(resourcePolicyId);
     });
   });
 
   describe('update', () => {
-    it('should proxy the call to dataservice.update', () => {
+    it('should proxy the call to updateData.update', () => {
       scheduler.schedule(() => service.update(resourcePolicy));
       scheduler.flush();
 
-      expect((service as any).dataService.update).toHaveBeenCalledWith(resourcePolicy);
+      expect((service as any).patchData.update).toHaveBeenCalledWith(resourcePolicy);
     });
   });
 
   describe('findById', () => {
-    it('should proxy the call to dataservice.findById', () => {
-      scheduler.schedule(() => service.findById(resourcePolicyId));
-      scheduler.flush();
-
-      expect((service as any).dataService.findById).toHaveBeenCalledWith(resourcePolicyId, true, true);
-    });
-
     it('should return a RemoteData<ResourcePolicy> for the object with the given id', () => {
       const result = service.findById(resourcePolicyId);
       const expected = cold('a|', {
@@ -223,13 +214,6 @@ describe('ResourcePolicyService', () => {
   });
 
   describe('findByHref', () => {
-    it('should proxy the call to dataservice.findByHref', () => {
-      scheduler.schedule(() => service.findByHref(requestURL));
-      scheduler.flush();
-
-      expect((service as any).dataService.findByHref).toHaveBeenCalledWith(requestURL, true, true);
-    });
-
     it('should return a RemoteData<ResourcePolicy> for the object with the given URL', () => {
       const result = service.findByHref(requestURL);
       const expected = cold('a|', {
@@ -240,16 +224,16 @@ describe('ResourcePolicyService', () => {
   });
 
   describe('searchByEPerson', () => {
-    it('should proxy the call to dataservice.searchBy', () => {
+    it('should proxy the call to searchData.searchBy', () => {
       const options = new FindListOptions();
       options.searchParams = [new RequestParam('uuid', epersonUUID)];
       scheduler.schedule(() => service.searchByEPerson(epersonUUID));
       scheduler.flush();
 
-      expect((service as any).dataService.searchBy).toHaveBeenCalledWith((service as any).searchByEPersonMethod, options, true, true);
+      expect((service as any).searchData.searchBy).toHaveBeenCalledWith((service as any).searchByEPersonMethod, options, true, true);
     });
 
-    it('should proxy the call to dataservice.searchBy with additional search param', () => {
+    it('should proxy the call to searchData.searchBy with additional search param', () => {
       const options = new FindListOptions();
       options.searchParams = [
         new RequestParam('uuid', epersonUUID),
@@ -258,7 +242,7 @@ describe('ResourcePolicyService', () => {
       scheduler.schedule(() => service.searchByEPerson(epersonUUID, resourceUUID));
       scheduler.flush();
 
-      expect((service as any).dataService.searchBy).toHaveBeenCalledWith((service as any).searchByEPersonMethod, options, true, true);
+      expect((service as any).searchData.searchBy).toHaveBeenCalledWith((service as any).searchByEPersonMethod, options, true, true);
     });
 
     it('should return a RemoteData<PaginatedList<ResourcePolicy>) for the search', () => {
@@ -272,16 +256,16 @@ describe('ResourcePolicyService', () => {
   });
 
   describe('searchByGroup', () => {
-    it('should proxy the call to dataservice.searchBy', () => {
+    it('should proxy the call to searchData.searchBy', () => {
       const options = new FindListOptions();
       options.searchParams = [new RequestParam('uuid', groupUUID)];
       scheduler.schedule(() => service.searchByGroup(groupUUID));
       scheduler.flush();
 
-      expect((service as any).dataService.searchBy).toHaveBeenCalledWith((service as any).searchByGroupMethod, options, true, true);
+      expect((service as any).searchData.searchBy).toHaveBeenCalledWith((service as any).searchByGroupMethod, options, true, true);
     });
 
-    it('should proxy the call to dataservice.searchBy with additional search param', () => {
+    it('should proxy the call to searchData.searchBy with additional search param', () => {
       const options = new FindListOptions();
       options.searchParams = [
         new RequestParam('uuid', groupUUID),
@@ -290,7 +274,7 @@ describe('ResourcePolicyService', () => {
       scheduler.schedule(() => service.searchByGroup(groupUUID, resourceUUID));
       scheduler.flush();
 
-      expect((service as any).dataService.searchBy).toHaveBeenCalledWith((service as any).searchByGroupMethod, options, true, true);
+      expect((service as any).searchData.searchBy).toHaveBeenCalledWith((service as any).searchByGroupMethod, options, true, true);
     });
 
     it('should return a RemoteData<PaginatedList<ResourcePolicy>) for the search', () => {
@@ -304,16 +288,16 @@ describe('ResourcePolicyService', () => {
   });
 
   describe('searchByResource', () => {
-    it('should proxy the call to dataservice.searchBy', () => {
+    it('should proxy the call to searchData.searchBy', () => {
       const options = new FindListOptions();
       options.searchParams = [new RequestParam('uuid', resourceUUID)];
       scheduler.schedule(() => service.searchByResource(resourceUUID));
       scheduler.flush();
 
-      expect((service as any).dataService.searchBy).toHaveBeenCalledWith((service as any).searchByResourceMethod, options, true, true);
+      expect((service as any).searchData.searchBy).toHaveBeenCalledWith((service as any).searchByResourceMethod, options, true, true);
     });
 
-    it('should proxy the call to dataservice.searchBy with additional search param', () => {
+    it('should proxy the call to searchData.searchBy with additional search param', () => {
       const action = ActionType.READ;
       const options = new FindListOptions();
       options.searchParams = [
@@ -323,7 +307,7 @@ describe('ResourcePolicyService', () => {
       scheduler.schedule(() => service.searchByResource(resourceUUID, action));
       scheduler.flush();
 
-      expect((service as any).dataService.searchBy).toHaveBeenCalledWith((service as any).searchByResourceMethod, options, true, true);
+      expect((service as any).searchData.searchBy).toHaveBeenCalledWith((service as any).searchByResourceMethod, options, true, true);
     });
 
     it('should return a RemoteData<PaginatedList<ResourcePolicy>) for the search', () => {

src/app/core/resource-policy/resource-policy.service.ts

@@ -1,13 +1,8 @@
-/* eslint-disable max-classes-per-file */
 import { Injectable } from '@angular/core';
-import { HttpClient, HttpHeaders } from '@angular/common/http';
+import { HttpHeaders } from '@angular/common/http';
-
-import { Store } from '@ngrx/store';
 import { Observable } from 'rxjs';
 import { FollowLinkConfig } from '../../shared/utils/follow-link-config.model';
 import { dataService } from '../cache/builders/build-decorators';
-
-import { DataService } from '../data/data.service';
 import { RequestService } from '../data/request.service';
 import { Collection } from '../shared/collection.model';
 import { HALEndpointService } from '../shared/hal-endpoint.service';
@@ -17,7 +12,6 @@ import { RemoteDataBuildService } from '../cache/builders/remote-data-build.serv
 import { ObjectCacheService } from '../cache/object-cache.service';
 import { NotificationsService } from '../../shared/notifications/notifications.service';
 import { RESOURCE_POLICY } from './models/resource-policy.resource-type';
-import { ChangeAnalyzer } from '../data/change-analyzer';
 import { DefaultChangeAnalyzer } from '../data/default-change-analyzer.service';
 import { PaginatedList } from '../data/paginated-list.model';
 import { ActionType } from './models/action-type.model';
@@ -26,7 +20,6 @@ import { isNotEmpty } from '../../shared/empty.util';
 import { map, take } from 'rxjs/operators';
 import { NoContent } from '../shared/NoContent.model';
 import { getFirstCompletedRemoteData } from '../shared/operators';
-import { CoreState } from '../core-state.model';
 import { FindListOptions } from '../data/find-list-options.model';
 import { HttpOptions } from '../dspace-rest/dspace-rest.service';
 import { PutRequest } from '../data/request.models';
@@ -36,52 +29,43 @@ import { StatusCodeOnlyResponseParsingService } from '../data/status-code-only-r
 import { HALLink } from '../shared/hal-link.model';
 import { EPersonDataService } from '../eperson/eperson-data.service';
 import { GroupDataService } from '../eperson/group-data.service';
-
+import { IdentifiableDataService } from '../data/base/identifiable-data.service';
-
+import { CreateDataImpl } from '../data/base/create-data';
-/**
+import { SearchDataImpl } from '../data/base/search-data';
- * A private DataService implementation to delegate specific methods to.
+import { PatchDataImpl } from '../data/base/patch-data';
- */
+import { DeleteDataImpl } from '../data/base/delete-data';
-class DataServiceImpl extends DataService<ResourcePolicy> {
-  protected linkPath = 'resourcepolicies';
-
-  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: ChangeAnalyzer<ResourcePolicy>,
-  ) {
-    super();
-  }
-
-}
 
 /**
  * A service responsible for fetching/sending data from/to the REST API on the resourcepolicies endpoint
  */
 @Injectable()
 @dataService(RESOURCE_POLICY)
-export class ResourcePolicyService {
+export class ResourcePolicyService extends IdentifiableDataService<ResourcePolicy> {
-  private dataService: DataServiceImpl;
   protected searchByEPersonMethod = 'eperson';
   protected searchByGroupMethod = 'group';
   protected searchByResourceMethod = 'resource';
 
+  private createData: CreateDataImpl<ResourcePolicy>;
+  private searchData: SearchDataImpl<ResourcePolicy>;
+  private patchData: PatchDataImpl<ResourcePolicy>;
+  private deleteData: DeleteDataImpl<ResourcePolicy>;
+
   constructor(
     protected requestService: RequestService,
     protected rdbService: RemoteDataBuildService,
     protected objectCache: ObjectCacheService,
     protected halService: HALEndpointService,
     protected notificationsService: NotificationsService,
-    protected http: HttpClient,
     protected comparator: DefaultChangeAnalyzer<ResourcePolicy>,
     protected ePersonService: EPersonDataService,
     protected groupService: GroupDataService,
   ) {
-    this.dataService = new DataServiceImpl(requestService, rdbService, null, objectCache, halService, notificationsService, http, comparator);
+    super('resourcepolicies', 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.patchData = new PatchDataImpl(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);
   }
 
   /**
@@ -105,7 +89,7 @@ export class ResourcePolicyService {
     } else if (isNotEmpty(groupUUID)) {
       params.push(new RequestParam('group', groupUUID));
     }
-    return this.dataService.create(resourcePolicy, ...params);
+    return this.createData.create(resourcePolicy, ...params);
   }
 
   /**
@@ -115,9 +99,9 @@ export class ResourcePolicyService {
    * @return an observable that emits true when the deletion was successful, false when it failed
    */
   delete(resourcePolicyID: string): Observable<boolean> {
-    return this.dataService.delete(resourcePolicyID).pipe(
+    return this.deleteData.delete(resourcePolicyID).pipe(
       getFirstCompletedRemoteData(),
-      map((response: RemoteData<NoContent>) => response.hasSucceeded)
+      map((response: RemoteData<NoContent>) => response.hasSucceeded),
     );
   }
 
@@ -127,37 +111,7 @@ export class ResourcePolicyService {
    * @param {ResourcePolicy} object The given object
    */
   update(object: ResourcePolicy): Observable<RemoteData<ResourcePolicy>> {
-    return this.dataService.update(object);
+    return this.patchData.update(object);
-  }
-
-  /**
-   * Returns an observable of {@link RemoteData} of a {@link ResourcePolicy}, based on an href, with a list of {@link FollowLinkConfig},
-   * to automatically resolve {@link HALLink}s of the {@link ResourcePolicy}
-   * @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<ResourcePolicy>[]): Observable<RemoteData<ResourcePolicy>> {
-    return this.dataService.findByHref(href, useCachedVersionIfAvailable, reRequestOnStale, ...linksToFollow);
-  }
-
-  /**
-   * Returns an observable of {@link RemoteData} of a {@link ResourcePolicy}, based on its ID, with a list of {@link FollowLinkConfig},
-   * to automatically resolve {@link HALLink}s of the object
-   * @param id                          ID of {@link ResourcePolicy} 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<ResourcePolicy>[]): Observable<RemoteData<ResourcePolicy>> {
-    return this.dataService.findById(id, useCachedVersionIfAvailable, reRequestOnStale, ...linksToFollow);
   }
 
   /**
@@ -167,7 +121,7 @@ export class ResourcePolicyService {
    * @param findListOptions the {@link FindListOptions} for the request
    */
   getDefaultAccessConditionsFor(collection: Collection, findListOptions?: FindListOptions): Observable<RemoteData<PaginatedList<ResourcePolicy>>> {
-    return this.dataService.findAllByHref(collection._links.defaultAccessConditions.href, findListOptions);
+    return this.findAllByHref(collection._links.defaultAccessConditions.href, findListOptions);
   }
 
   /**
@@ -188,7 +142,7 @@ export class ResourcePolicyService {
     if (isNotEmpty(resourceUUID)) {
       options.searchParams.push(new RequestParam('resource', resourceUUID));
     }
-    return this.dataService.searchBy(this.searchByEPersonMethod, options, useCachedVersionIfAvailable, reRequestOnStale, ...linksToFollow);
+    return this.searchData.searchBy(this.searchByEPersonMethod, options, useCachedVersionIfAvailable, reRequestOnStale, ...linksToFollow);
   }
 
   /**
@@ -209,7 +163,7 @@ export class ResourcePolicyService {
     if (isNotEmpty(resourceUUID)) {
       options.searchParams.push(new RequestParam('resource', resourceUUID));
     }
-    return this.dataService.searchBy(this.searchByGroupMethod, options, useCachedVersionIfAvailable, reRequestOnStale, ...linksToFollow);
+    return this.searchData.searchBy(this.searchByGroupMethod, options, useCachedVersionIfAvailable, reRequestOnStale, ...linksToFollow);
   }
 
   /**
@@ -230,7 +184,7 @@ export class ResourcePolicyService {
     if (isNotEmpty(action)) {
       options.searchParams.push(new RequestParam('action', action));
     }
-    return this.dataService.searchBy(this.searchByResourceMethod, options, useCachedVersionIfAvailable, reRequestOnStale, ...linksToFollow);
+    return this.searchData.searchBy(this.searchByResourceMethod, options, useCachedVersionIfAvailable, reRequestOnStale, ...linksToFollow);
   }
 
   /**
@@ -256,7 +210,7 @@ export class ResourcePolicyService {
 
     const requestId = this.requestService.generateRequestId();
 
-    this.requestService.setStaleByHrefSubstring(`${this.dataService.getLinkPath()}/${resourcePolicyId}/${targetType}`);
+    this.requestService.setStaleByHrefSubstring(`${this.getLinkPath()}/${resourcePolicyId}/${targetType}`);
 
     targetEndpoint$.subscribe((targetEndpoint) => {
       const resourceEndpoint = resourcePolicyHref + '/' + targetType;

src/app/core/shared/search/search.service.ts

@@ -1,14 +1,12 @@
 /* eslint-disable max-classes-per-file */
 import { combineLatest as observableCombineLatest, Observable } from 'rxjs';
 import { Injectable, OnDestroy } from '@angular/core';
-import { Router } from '@angular/router';
 import { map, switchMap, take } from 'rxjs/operators';
 import { FollowLinkConfig } from '../../../shared/utils/follow-link-config.model';
-import { LinkService } from '../../cache/builders/link.service';
 import { PaginatedList } from '../../data/paginated-list.model';
 import { ResponseParsingService } from '../../data/parsing.service';
 import { RemoteData } from '../../data/remote-data';
-import { GetRequest} from '../../data/request.models';
+import { GetRequest } from '../../data/request.models';
 import { RequestService } from '../../data/request.service';
 import { DSpaceObject } from '../dspace-object.model';
 import { GenericConstructor } from '../generic-constructor';
@@ -21,7 +19,6 @@ import { SearchResponseParsingService } from '../../data/search-response-parsing
 import { SearchObjects } from '../../../shared/search/models/search-objects.model';
 import { FacetValueResponseParsingService } from '../../data/facet-value-response-parsing.service';
 import { PaginatedSearchOptions } from '../../../shared/search/models/paginated-search-options.model';
-import { CommunityDataService } from '../../data/community-data.service';
 import { ViewMode } from '../view-mode.model';
 import { DSpaceObjectDataService } from '../../data/dspace-object-data.service';
 import { RemoteDataBuildService } from '../../cache/builders/remote-data-build.service';
@@ -34,31 +31,19 @@ import { FacetValues } from '../../../shared/search/models/facet-values.model';
 import { PaginationService } from '../../pagination/pagination.service';
 import { SearchConfigurationService } from './search-configuration.service';
 import { PaginationComponentOptions } from '../../../shared/pagination/pagination-component-options.model';
-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 { DSOChangeAnalyzer } from '../../data/dso-change-analyzer.service';
 import { RestRequest } from '../../data/rest-request.model';
-import { CoreState } from '../../core-state.model';
+import { BaseDataService } from '../../data/base/base-data.service';
 
 /**
- * A class that lets us delegate some methods to DataService
+ * A limited data service implementation for the 'discover' endpoint
+ * - Overrides {@link BaseDataService.addEmbedParams} in order to make it public
+ *
+ * Doesn't use any of the service's dependencies, they are initialized as undefined
+ * Therefore, equest/response handling methods won't work even though they're defined
  */
-class DataServiceImpl extends DataService<any> {
+class SearchDataService extends BaseDataService<any> {
-  protected linkPath = 'discover';
+  constructor() {
-
+    super('discover', undefined, undefined, undefined, 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: DSOChangeAnalyzer<any>) {
-    super();
   }
 
   /**
@@ -99,31 +84,20 @@ export class SearchService implements OnDestroy {
   private sub;
 
   /**
-   * Instance of DataServiceImpl that lets us delegate some methods to DataService
+   * Instance of SearchDataService to forward data service methods to
    */
-  private searchDataService: DataServiceImpl;
+  private searchDataService: SearchDataService;
 
-  constructor(private router: Router,
+  constructor(
-              private routeService: RouteService,
+    private routeService: RouteService,
-              protected requestService: RequestService,
+    protected requestService: RequestService,
-              private rdb: RemoteDataBuildService,
+    private rdb: RemoteDataBuildService,
-              private linkService: LinkService,
+    private halService: HALEndpointService,
-              private halService: HALEndpointService,
+    private dspaceObjectService: DSpaceObjectDataService,
-              private communityService: CommunityDataService,
+    private paginationService: PaginationService,
-              private dspaceObjectService: DSpaceObjectDataService,
+    private searchConfigurationService: SearchConfigurationService,
-              private paginationService: PaginationService,
-              private searchConfigurationService: SearchConfigurationService
   ) {
-    this.searchDataService = new DataServiceImpl(
+    this.searchDataService = new SearchDataService();
-      undefined,
-      undefined,
-      undefined,
-      undefined,
-      undefined,
-      undefined,
-      undefined,
-      undefined
-    );
   }
 
   /**

src/app/core/statistics/usage-report-data.service.ts

@@ -1,41 +1,38 @@
-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/data.service';
 import { RequestService } from '../data/request.service';
-import { DefaultChangeAnalyzer } from '../data/default-change-analyzer.service';
 import { USAGE_REPORT } from './models/usage-report.resource-type';
 import { UsageReport } from './models/usage-report.model';
 import { Observable } from 'rxjs';
-import { getRemoteDataPayload, getFirstSucceededRemoteData } from '../shared/operators';
+import { getFirstSucceededRemoteData, getRemoteDataPayload } from '../shared/operators';
 import { map } from 'rxjs/operators';
-import { CoreState } from '../core-state.model';
+import { IdentifiableDataService } from '../data/base/identifiable-data.service';
+import { SearchData, SearchDataImpl } from '../data/base/search-data';
+import { FindListOptions } from '../data/find-list-options.model';
+import { FollowLinkConfig } from '../../shared/utils/follow-link-config.model';
+import { RemoteData } from '../data/remote-data';
+import { PaginatedList } from '../data/paginated-list.model';
 
 /**
  * A service to retrieve {@link UsageReport}s from the REST API
  */
 @Injectable()
 @dataService(USAGE_REPORT)
-export class UsageReportService extends DataService<UsageReport> {
+export class UsageReportService extends IdentifiableDataService<UsageReport> implements SearchData<UsageReport> {
-
+  private searchData: SearchDataImpl<UsageReport>;
-  protected linkPath = 'usagereports';
 
   constructor(
-    protected comparator: DefaultChangeAnalyzer<UsageReport>,
-    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 halService: HALEndpointService,
+    protected objectCache: ObjectCacheService,
   ) {
-    super();
+    super('usagereports', requestService, rdbService, objectCache, halService);
+
+    this.searchData = new SearchDataImpl(this.linkPath, requestService, rdbService, objectCache, halService, this.responseMsToLive);
   }
 
   getStatistic(scope: string, type: string): Observable<UsageReport> {
@@ -47,10 +44,12 @@ export class UsageReportService extends DataService<UsageReport> {
 
   searchStatistics(uri: string, page: number, size: number): Observable<UsageReport[]> {
     return this.searchBy('object', {
-      searchParams: [{
+      searchParams: [
-        fieldName: `uri`,
+        {
-        fieldValue: uri,
+          fieldName: `uri`,
-      }],
+          fieldValue: uri,
+        },
+      ],
       currentPage: page,
       elementsPerPage: size,
     }, true, false).pipe(
@@ -59,4 +58,8 @@ export class UsageReportService extends DataService<UsageReport> {
       map((list) => list.page),
     );
   }
+
+  public searchBy(searchMethod: string, options?: FindListOptions, useCachedVersionIfAvailable?: boolean, reRequestOnStale?: boolean, ...linksToFollow: FollowLinkConfig<UsageReport>[]): Observable<RemoteData<PaginatedList<UsageReport>>> {
+    return this.searchData.searchBy(searchMethod, options, useCachedVersionIfAvailable, reRequestOnStale, ...linksToFollow);
+  }
 }

src/app/core/submission/resolver/submission-object.resolver.ts

@@ -1,14 +1,12 @@
-import { DSpaceObject } from './../../shared/dspace-object.model';
+import { followLink } from '../../../shared/utils/follow-link-config.model';
-import { followLink } from './../../../shared/utils/follow-link-config.model';
-import { ChildHALResource } from './../../shared/child-hal-resource.model';
 import { Injectable } from '@angular/core';
 import { ActivatedRouteSnapshot, Resolve, RouterStateSnapshot } from '@angular/router';
 import { Observable } from 'rxjs';
 import { Store } from '@ngrx/store';
 import { switchMap } from 'rxjs/operators';
-import { DataService } from '../../data/data.service';
 import { RemoteData } from '../../data/remote-data';
 import { getFirstCompletedRemoteData } from '../../shared/operators';
+import { IdentifiableDataService } from '../../data/base/identifiable-data.service';
 
 /**
  * This class represents a resolver that requests a specific item before the route is activated
@@ -16,8 +14,8 @@ import { getFirstCompletedRemoteData } from '../../shared/operators';
 @Injectable()
 export class SubmissionObjectResolver<T> implements Resolve<RemoteData<T>> {
     constructor(
-        protected dataService: DataService<any>,
+      protected dataService: IdentifiableDataService<any>,
-        protected store: Store<any>
+      protected store: Store<any>,
     ) {
     }
 

src/app/core/submission/submission-cc-license-data.service.ts

@@ -1,34 +1,49 @@
-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/data.service';
 import { RequestService } from '../data/request.service';
 import { SUBMISSION_CC_LICENSE } from './models/submission-cc-licence.resource-type';
 import { SubmissionCcLicence } from './models/submission-cc-license.model';
-import { DefaultChangeAnalyzer } from '../data/default-change-analyzer.service';
+import { BaseDataService } from '../data/base/base-data.service';
-import { CoreState } from '../core-state.model';
+import { FindAllData } from '../data/base/find-all-data';
+import { FindListOptions } from '../data/find-list-options.model';
+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';
 
 @Injectable()
 @dataService(SUBMISSION_CC_LICENSE)
-export class SubmissionCcLicenseDataService extends DataService<SubmissionCcLicence> {
+export class SubmissionCcLicenseDataService extends BaseDataService<SubmissionCcLicence> implements FindAllData<SubmissionCcLicence> {
 
   protected linkPath = 'submissioncclicenses';
 
   constructor(
-    protected comparator: DefaultChangeAnalyzer<SubmissionCcLicence>,
-    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('submissioncclicenses', requestService, rdbService, objectCache, halService);
+  }
+
+  /**
+   * 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<SubmissionCcLicence>[]): Observable<RemoteData<PaginatedList<SubmissionCcLicence>>> {
+    return undefined;
   }
 }

src/app/core/submission/submission-cc-license-url-data.service.ts

@@ -1,40 +1,36 @@
-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/data.service';
 import { RequestService } from '../data/request.service';
-import { DefaultChangeAnalyzer } from '../data/default-change-analyzer.service';
 import { SubmissionCcLicenceUrl } from './models/submission-cc-license-url.model';
 import { SUBMISSION_CC_LICENSE_URL } from './models/submission-cc-licence-link.resource-type';
 import { Field, Option, SubmissionCcLicence } from './models/submission-cc-license.model';
 import { Observable } from 'rxjs';
-import { filter, map, switchMap } from 'rxjs/operators';
+import { map, switchMap } from 'rxjs/operators';
 import { getRemoteDataPayload, getFirstSucceededRemoteData } from '../shared/operators';
-import { isNotEmpty } from '../../shared/empty.util';
+import { BaseDataService } from '../data/base/base-data.service';
-import { CoreState } from '../core-state.model';
+import { SearchData, SearchDataImpl } from '../data/base/search-data';
+import { FindListOptions } from '../data/find-list-options.model';
+import { FollowLinkConfig } from '../../shared/utils/follow-link-config.model';
+import { RemoteData } from '../data/remote-data';
+import { PaginatedList } from '../data/paginated-list.model';
 
 @Injectable()
 @dataService(SUBMISSION_CC_LICENSE_URL)
-export class SubmissionCcLicenseUrlDataService extends DataService<SubmissionCcLicenceUrl> {
+export class SubmissionCcLicenseUrlDataService extends BaseDataService<SubmissionCcLicenceUrl> implements SearchData<SubmissionCcLicenceUrl> {
-
+  private searchData: SearchData<SubmissionCcLicenceUrl>;
-  protected linkPath = 'submissioncclicenseUrls-search';
 
   constructor(
-    protected comparator: DefaultChangeAnalyzer<SubmissionCcLicenceUrl>,
-    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('submissioncclicenseUrls-search', requestService, rdbService, objectCache, halService);
+
+    this.searchData = new SearchDataImpl(this.linkPath, requestService, rdbService, objectCache, halService, this.responseMsToLive, (href, searchMethod) => `${href}/${searchMethod}`);
   }
 
   /**
@@ -68,9 +64,34 @@ export class SubmissionCcLicenseUrlDataService extends DataService<SubmissionCcL
     );
   }
 
-  protected getSearchEndpoint(searchMethod: string): Observable<string> {
+  /**
-    return this.halService.getEndpoint(`${this.linkPath}`).pipe(
+   * Create the HREF for a specific object's search method with given options object
-      filter((href: string) => isNotEmpty(href)),
+   *
-      map((href: string) => `${href}/${searchMethod}`));
+   * @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<SubmissionCcLicenceUrl>[]): 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<SubmissionCcLicenceUrl>[]): Observable<RemoteData<PaginatedList<SubmissionCcLicenceUrl>>> {
+    return this.searchData.searchBy(searchMethod, options, useCachedVersionIfAvailable, reRequestOnStale, ...linksToFollow);
   }
 }

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

@@ -7,11 +7,11 @@ import { SubmissionObject } from './models/submission-object.model';
 import { SubmissionScopeType } from './submission-scope-type';
 import { WorkflowItemDataService } from './workflowitem-data.service';
 import { WorkspaceitemDataService } from './workspaceitem-data.service';
-import { DataService } from '../data/data.service';
 import { map } from 'rxjs/operators';
 import { HALEndpointService } from '../shared/hal-endpoint.service';
 import { environment } from '../../../environments/environment';
 import { RequestEntryState } from '../data/request-entry-state.model';
+import { IdentifiableDataService } from '../data/base/identifiable-data.service';
 
 /**
  * A service to retrieve submission objects (WorkspaceItem/WorkflowItem)
@@ -34,7 +34,7 @@ export class SubmissionObjectDataService {
    * @param id The identifier for the object
    */
   getHrefByID(id): Observable<string> {
-    const dataService: DataService<SubmissionObject> = this.submissionService.getSubmissionScope() === SubmissionScopeType.WorkspaceItem ? this.workspaceitemDataService : this.workflowItemDataService;
+    const dataService: IdentifiableDataService<SubmissionObject> = this.submissionService.getSubmissionScope() === SubmissionScopeType.WorkspaceItem ? this.workspaceitemDataService : this.workflowItemDataService;
 
     return this.halService.getEndpoint(dataService.getLinkPath()).pipe(
       map((endpoint: string) => dataService.getIDHref(endpoint, encodeURIComponent(id))));

src/app/core/submission/vocabularies/vocabulary-entry-details.data.service.spec.ts

@@ -0,0 +1,16 @@
+/**
+ * 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 '../../data/base/find-all-data.spec';
+import { VocabularyEntryDetailsDataService } from './vocabulary-entry-details.data.service';
+import { testSearchDataImplementation } from '../../data/base/search-data.spec';
+
+describe('VocabularyEntryDetailsDataService', () => {
+  testFindAllDataImplementation(new VocabularyEntryDetailsDataService(null, null, null, null));
+  testSearchDataImplementation(new VocabularyEntryDetailsDataService(null, null, null, null));
+});

src/app/core/submission/vocabularies/vocabulary-entry-details.data.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/
+ */
+import { IdentifiableDataService } from '../../data/base/identifiable-data.service';
+import { VocabularyEntryDetail } from './models/vocabulary-entry-detail.model';
+import { RequestService } from '../../data/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 { FindAllData, FindAllDataImpl } from '../../data/base/find-all-data';
+import { FindListOptions } from '../../data/find-list-options.model';
+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 { SearchData, SearchDataImpl } from '../../data/base/search-data';
+import { Injectable } from '@angular/core';
+import { dataService } from '../../cache/builders/build-decorators';
+import { VOCABULARY_ENTRY_DETAIL } from './models/vocabularies.resource-type';
+
+@Injectable()
+@dataService(VOCABULARY_ENTRY_DETAIL)
+export class VocabularyEntryDetailsDataService extends IdentifiableDataService<VocabularyEntryDetail> implements FindAllData<VocabularyEntryDetail>, SearchData<VocabularyEntryDetail> {
+  private findAllData: FindAllData<VocabularyEntryDetail>;
+  private searchData: SearchData<VocabularyEntryDetail>;
+
+  constructor(
+    protected requestService: RequestService,
+    protected rdbService: RemoteDataBuildService,
+    protected objectCache: ObjectCacheService,
+    protected halService: HALEndpointService,
+  ) {
+    super('vocabularyEntryDetails', requestService, rdbService, objectCache, halService);
+
+    this.findAllData = new FindAllDataImpl(this.linkPath, requestService, rdbService, objectCache, halService, this.responseMsToLive);
+    this.searchData = new SearchDataImpl(this.linkPath, requestService, rdbService, objectCache, halService, this.responseMsToLive);
+  }
+
+  /**
+   * 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<VocabularyEntryDetail>[]): Observable<string> {
+    return this.findAllData.getFindAllHref(options, linkPath, ...linksToFollow);
+  }
+
+  /**
+   * 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<VocabularyEntryDetail>[]): Observable<RemoteData<PaginatedList<VocabularyEntryDetail>>> {
+    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<VocabularyEntryDetail>[]): Observable<RemoteData<PaginatedList<VocabularyEntryDetail>>> {
+    return this.searchData.searchBy(searchMethod, options, 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
+   */
+  public getSearchByHref(searchMethod: string, options?: FindListOptions, ...linksToFollow): Observable<string> {
+    return this.searchData.getSearchByHref(searchMethod, options, ...linksToFollow);
+  }
+}

src/app/core/submission/vocabularies/vocabulary.data.service.spec.ts

@@ -0,0 +1,14 @@
+/**
+ * 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 { VocabularyDataService } from './vocabulary.data.service';
+import { testFindAllDataImplementation } from '../../data/base/find-all-data.spec';
+
+
+describe('VocabularyDataService', () => {
+  testFindAllDataImplementation(new VocabularyDataService(null, null, null, null));
+});

src/app/core/submission/vocabularies/vocabulary.data.service.ts

@@ -0,0 +1,70 @@
+/**
+ * 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 { IdentifiableDataService } from '../../data/base/identifiable-data.service';
+import { RequestService } from '../../data/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 { Vocabulary } from './models/vocabulary.model';
+import { FindAllData, FindAllDataImpl } from '../../data/base/find-all-data';
+import { FindListOptions } from '../../data/find-list-options.model';
+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 { Injectable } from '@angular/core';
+import { dataService } from '../../cache/builders/build-decorators';
+import { VOCABULARY } from './models/vocabularies.resource-type';
+
+@Injectable()
+@dataService(VOCABULARY)
+export class VocabularyDataService extends IdentifiableDataService<Vocabulary> implements FindAllData<Vocabulary> {
+  private findAllData: FindAllData<Vocabulary>;
+
+  constructor(
+    protected requestService: RequestService,
+    protected rdbService: RemoteDataBuildService,
+    protected objectCache: ObjectCacheService,
+    protected halService: HALEndpointService,
+  ) {
+    super('vocabularies', requestService, rdbService, objectCache, halService);
+
+    this.findAllData = new FindAllDataImpl(this.linkPath, requestService, rdbService, objectCache, halService, this.responseMsToLive);
+  }
+
+  /**
+   * 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<Vocabulary>[]): Observable<string> {
+    return this.findAllData.getFindAllHref(options, linkPath, ...linksToFollow);
+  }
+
+  /**
+   * 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<Vocabulary>[]): Observable<RemoteData<PaginatedList<Vocabulary>>> {
+    return this.findAllData.findAll(options, useCachedVersionIfAvailable, reRequestOnStale, ...linksToFollow);
+  }
+}

src/app/core/submission/vocabularies/vocabulary.service.spec.ts

@@ -1,10 +1,7 @@
-import { HttpClient } from '@angular/common/http';
-
 import { cold, getTestScheduler, hot } from 'jasmine-marbles';
 import { of as observableOf } from 'rxjs';
 import { TestScheduler } from 'rxjs/testing';
 
-import { NotificationsService } from '../../../shared/notifications/notifications.service';
 import { RemoteDataBuildService } from '../../cache/builders/remote-data-build.service';
 import { ObjectCacheService } from '../../cache/object-cache.service';
 import { HALEndpointService } from '../../shared/hal-endpoint.service';
@@ -26,6 +23,8 @@ import { HrefOnlyDataService } from '../../data/href-only-data.service';
 import { getMockHrefOnlyDataService } from '../../../shared/mocks/href-only-data.service.mock';
 import { createPaginatedList } from '../../../shared/testing/utils.test';
 import { RequestEntry } from '../../data/request-entry.model';
+import { VocabularyDataService } from './vocabulary.data.service';
+import { VocabularyEntryDetailsDataService } from './vocabulary-entry-details.data.service';
 
 describe('VocabularyService', () => {
   let scheduler: TestScheduler;
@@ -203,24 +202,14 @@ describe('VocabularyService', () => {
       response: { isSuccessful: successful, payload: arrayEntries } as any
     } as RequestEntry);
   };
-  objectCache = {} as ObjectCacheService;
-  const notificationsService = {} as NotificationsService;
-  const http = {} as HttpClient;
-  const comparator = {} as any;
-  const comparatorEntry = {} as any;
 
   function initTestService() {
     hrefOnlyDataService = getMockHrefOnlyDataService();
+
     return new VocabularyService(
       requestService,
-      rdbService,
+      new VocabularyDataService(requestService, rdbService, objectCache, halService),
-      objectCache,
+      new VocabularyEntryDetailsDataService(requestService, rdbService, objectCache, halService),
-      halService,
-      notificationsService,
-      hrefOnlyDataService,
-      http,
-      comparator,
-      comparatorEntry
     );
   }
 
@@ -229,7 +218,7 @@ describe('VocabularyService', () => {
       scheduler = getTestScheduler();
 
       halService = jasmine.createSpyObj('halService', {
-        getEndpoint: cold('a', { a: endpointURL })
+        getEndpoint: cold('a', { a: endpointURL }),
       });
     });
 
@@ -237,7 +226,7 @@ describe('VocabularyService', () => {
       service = null;
     });
 
-    describe('', () => {
+    describe('vocabularies', () => {
       beforeEach(() => {
         responseCacheEntry = new RequestEntry();
         responseCacheEntry.request = { href: 'https://rest.api/' } as any;
@@ -255,7 +244,7 @@ describe('VocabularyService', () => {
             a: vocabularyRD
           }),
           buildList: hot('a|', {
-            a: paginatedListRD
+            a: paginatedListRD,
           }),
         });
 
@@ -264,8 +253,6 @@ describe('VocabularyService', () => {
         spyOn((service as any).vocabularyDataService, 'findById').and.callThrough();
         spyOn((service as any).vocabularyDataService, 'findAll').and.callThrough();
         spyOn((service as any).vocabularyDataService, 'findByHref').and.callThrough();
-        spyOn((service as any).vocabularyDataService, 'searchBy').and.callThrough();
-        spyOn((service as any).vocabularyDataService, 'getSearchByHref').and.returnValue(observableOf(searchRequestURL));
         spyOn((service as any).vocabularyDataService, 'getFindAllHref').and.returnValue(observableOf(entriesRequestURL));
       });
 
@@ -274,7 +261,7 @@ describe('VocabularyService', () => {
       });
 
       describe('findVocabularyById', () => {
-        it('should proxy the call to vocabularyDataService.findVocabularyById', () => {
+        it('should proxy the call to vocabularyDataService.findById', () => {
           scheduler.schedule(() => service.findVocabularyById(vocabularyId));
           scheduler.flush();
 
@@ -325,7 +312,7 @@ describe('VocabularyService', () => {
       });
     });
 
-    describe('', () => {
+    describe('vocabulary entries', () => {
 
       beforeEach(() => {
         requestService = getMockRequestService(getRequestEntries$(true));

src/app/core/submission/vocabularies/vocabulary.service.ts

@@ -1,104 +1,38 @@
-/* eslint-disable max-classes-per-file */
 import { Injectable } from '@angular/core';
-import { HttpClient } from '@angular/common/http';
-
-import { Store } from '@ngrx/store';
 import { Observable } from 'rxjs';
 import { map, switchMap, mergeMap } from 'rxjs/operators';
-
 import { FollowLinkConfig, followLink } from '../../../shared/utils/follow-link-config.model';
-import { dataService } from '../../cache/builders/build-decorators';
-import { DataService } from '../../data/data.service';
 import { RequestService } from '../../data/request.service';
-import { HALEndpointService } from '../../shared/hal-endpoint.service';
 import { RemoteData } from '../../data/remote-data';
-import { RemoteDataBuildService } from '../../cache/builders/remote-data-build.service';
-import { ObjectCacheService } from '../../cache/object-cache.service';
-import { NotificationsService } from '../../../shared/notifications/notifications.service';
-import { ChangeAnalyzer } from '../../data/change-analyzer';
-import { DefaultChangeAnalyzer } from '../../data/default-change-analyzer.service';
 import { PaginatedList } from '../../data/paginated-list.model';
 import { Vocabulary } from './models/vocabulary.model';
-import { VOCABULARY } from './models/vocabularies.resource-type';
 import { VocabularyEntry } from './models/vocabulary-entry.model';
 import { isNotEmpty } from '../../../shared/empty.util';
 import {
   getFirstSucceededRemoteDataPayload,
-  getFirstSucceededRemoteListPayload
+  getFirstSucceededRemoteListPayload,
 } from '../../shared/operators';
 import { VocabularyFindOptions } from './models/vocabulary-find-options.model';
 import { VocabularyEntryDetail } from './models/vocabulary-entry-detail.model';
 import { RequestParam } from '../../cache/models/request-param.model';
 import { VocabularyOptions } from './models/vocabulary-options.model';
 import { PageInfo } from '../../shared/page-info.model';
-import { HrefOnlyDataService } from '../../data/href-only-data.service';
-import { CoreState } from '../../core-state.model';
 import { FindListOptions } from '../../data/find-list-options.model';
-
+import { VocabularyEntryDetailsDataService } from './vocabulary-entry-details.data.service';
-
+import { VocabularyDataService } from './vocabulary.data.service';
-/**
- * A private DataService implementation to delegate specific methods to.
- */
-class VocabularyDataServiceImpl extends DataService<Vocabulary> {
-  protected linkPath = 'vocabularies';
-
-  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: ChangeAnalyzer<Vocabulary>) {
-    super();
-  }
-
-}
-
-/**
- * A private DataService implementation to delegate specific methods to.
- */
-class VocabularyEntryDetailDataServiceImpl extends DataService<VocabularyEntryDetail> {
-  protected linkPath = 'vocabularyEntryDetails';
-
-  constructor(
-    protected requestService: RequestService,
-    protected rdbService: RemoteDataBuildService,
-    protected store: Store<CoreState>,
-    protected objectCache: ObjectCacheService,
-    protected halService: HALEndpointService,
-    protected notificationsService: NotificationsService,
-    protected hrefOnlyDataService: HrefOnlyDataService,
-    protected http: HttpClient,
-    protected comparator: ChangeAnalyzer<VocabularyEntryDetail>) {
-    super();
-  }
-
-}
 
 /**
  * A service responsible for fetching/sending data from/to the REST API on the vocabularies endpoint
  */
 @Injectable()
-@dataService(VOCABULARY)
 export class VocabularyService {
   protected searchTopMethod = 'top';
-  private vocabularyDataService: VocabularyDataServiceImpl;
-  private vocabularyEntryDetailDataService: VocabularyEntryDetailDataServiceImpl;
 
   constructor(
     protected requestService: RequestService,
-    protected rdbService: RemoteDataBuildService,
+    protected vocabularyDataService: VocabularyDataService,
-    protected objectCache: ObjectCacheService,
+    protected vocabularyEntryDetailDataService: VocabularyEntryDetailsDataService,
-    protected halService: HALEndpointService,
+  ) {
-    protected notificationsService: NotificationsService,
-    protected hrefOnlyDataService: HrefOnlyDataService,
-    protected http: HttpClient,
-    protected comparatorVocabulary: DefaultChangeAnalyzer<Vocabulary>,
-    protected comparatorEntry: DefaultChangeAnalyzer<VocabularyEntryDetail>) {
-    this.vocabularyDataService = new VocabularyDataServiceImpl(requestService, rdbService, null, objectCache, halService, notificationsService, http, comparatorVocabulary);
-    this.vocabularyEntryDetailDataService = new VocabularyEntryDetailDataServiceImpl(requestService, rdbService, null, objectCache, halService, notificationsService, hrefOnlyDataService, http, comparatorEntry);
   }
 
   /**

src/app/core/submission/workflowitem-data.service.spec.ts

@@ -82,14 +82,11 @@ describe('WorkflowItemDataService test', () => {
   function initTestService() {
     hrefOnlyDataService = getMockHrefOnlyDataService();
     return new WorkflowItemDataService(
-      comparatorEntry,
-      halService,
-      http,
-      notificationsService,
       requestService,
       rdbService,
       objectCache,
-      store
+      halService,
+      notificationsService,
     );
   }
 

src/app/core/submission/workflowitem-data.service.ts

@@ -1,17 +1,12 @@
 import { Injectable } from '@angular/core';
-import { HttpClient } from '@angular/common/http';
-
-import { Store } from '@ngrx/store';
 import { dataService } from '../cache/builders/build-decorators';
 import { RemoteDataBuildService } from '../cache/builders/remote-data-build.service';
-import { DataService } from '../data/data.service';
 import { RequestService } from '../data/request.service';
 import { WorkflowItem } from './models/workflowitem.model';
 import { HALEndpointService } from '../shared/hal-endpoint.service';
 import { DeleteByIDRequest } from '../data/request.models';
 import { NotificationsService } from '../../shared/notifications/notifications.service';
 import { ObjectCacheService } from '../cache/object-cache.service';
-import { DSOChangeAnalyzer } from '../data/dso-change-analyzer.service';
 import { Observable } from 'rxjs';
 import { find, map } from 'rxjs/operators';
 import { hasValue } from '../../shared/empty.util';
@@ -21,29 +16,36 @@ import { getFirstCompletedRemoteData } from '../shared/operators';
 import { FollowLinkConfig } from '../../shared/utils/follow-link-config.model';
 import { WorkspaceItem } from './models/workspaceitem.model';
 import { RequestParam } from '../cache/models/request-param.model';
-import { CoreState } from '../core-state.model';
 import { FindListOptions } from '../data/find-list-options.model';
+import { IdentifiableDataService } from '../data/base/identifiable-data.service';
+import { SearchData, SearchDataImpl } from '../data/base/search-data';
+import { DeleteData, DeleteDataImpl } from '../data/base/delete-data';
+import { PaginatedList } from '../data/paginated-list.model';
 
 /**
  * A service that provides methods to make REST requests with workflow items endpoint.
  */
 @Injectable()
 @dataService(WorkflowItem.type)
-export class WorkflowItemDataService extends DataService<WorkflowItem> {
+export class WorkflowItemDataService extends IdentifiableDataService<WorkflowItem> implements SearchData<WorkflowItem>, DeleteData<WorkflowItem> {
   protected linkPath = 'workflowitems';
   protected searchByItemLinkPath = 'item';
   protected responseMsToLive = 10 * 1000;
 
+  private searchData: SearchDataImpl<WorkflowItem>;
+  private deleteData: DeleteDataImpl<WorkflowItem>;
+
   constructor(
-    protected comparator: DSOChangeAnalyzer<WorkflowItem>,
-    protected halService: HALEndpointService,
-    protected http: HttpClient,
-    protected notificationsService: NotificationsService,
     protected requestService: RequestService,
     protected rdbService: RemoteDataBuildService,
     protected objectCache: ObjectCacheService,
-    protected store: Store<CoreState>) {
+    protected halService: HALEndpointService,
-    super();
+    protected notificationsService: NotificationsService,
+  ) {
+    super('workspaceitems', requestService, rdbService, objectCache, halService);
+
+    this.searchData = new SearchDataImpl(this.linkPath, requestService, rdbService, objectCache, halService, this.responseMsToLive);
+    this.deleteData = new DeleteDataImpl(this.linkPath, requestService, rdbService, objectCache, halService, notificationsService, this.responseMsToLive, this.constructIdEndpoint);
   }
 
   /**
@@ -78,8 +80,8 @@ export class WorkflowItemDataService extends DataService<WorkflowItem> {
     const requestId = this.requestService.generateRequestId();
 
     const hrefObs = this.halService.getEndpoint(this.linkPath).pipe(
-      map((endpoint: string) => this.getIDHref(endpoint, id)),
+      map((endpoint: string) => this.deleteData.getIDHref(endpoint, id)),
-      map((endpoint: string) => endpoint + '?expunge=' + expunge)
+      map((endpoint: string) => endpoint + '?expunge=' + expunge),
     );
 
     hrefObs.pipe(
@@ -110,4 +112,47 @@ export class WorkflowItemDataService extends DataService<WorkflowItem> {
     return this.findByHref(href$, 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
+   */
+  public getSearchByHref(searchMethod: string, options?: FindListOptions, ...linksToFollow): 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<WorkspaceItem>[]): Observable<RemoteData<PaginatedList<WorkspaceItem>>> {
+    return this.searchData.searchBy(searchMethod, options, useCachedVersionIfAvailable, reRequestOnStale, ...linksToFollow);
+  }
+
+  /**
+   * 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/submission/workspaceitem-data.service.spec.ts

@@ -82,14 +82,11 @@ describe('WorkspaceitemDataService test', () => {
   function initTestService() {
     hrefOnlyDataService = getMockHrefOnlyDataService();
     return new WorkspaceitemDataService(
-      comparatorEntry,
-      halService,
-      http,
-      notificationsService,
       requestService,
       rdbService,
       objectCache,
-      store
+      halService,
+      notificationsService,
     );
   }
 

src/app/core/submission/workspaceitem-data.service.ts

@@ -1,42 +1,44 @@
 import { Injectable } from '@angular/core';
-import { HttpClient } from '@angular/common/http';
-
-import { Store } from '@ngrx/store';
 import { dataService } from '../cache/builders/build-decorators';
 import { RemoteDataBuildService } from '../cache/builders/remote-data-build.service';
-import { DataService } from '../data/data.service';
 import { RequestService } from '../data/request.service';
 import { HALEndpointService } from '../shared/hal-endpoint.service';
 import { NotificationsService } from '../../shared/notifications/notifications.service';
 import { ObjectCacheService } from '../cache/object-cache.service';
-import { DSOChangeAnalyzer } from '../data/dso-change-analyzer.service';
 import { WorkspaceItem } from './models/workspaceitem.model';
 import { Observable } from 'rxjs';
 import { RemoteData } from '../data/remote-data';
 import { FollowLinkConfig } from '../../shared/utils/follow-link-config.model';
 import { RequestParam } from '../cache/models/request-param.model';
-import { CoreState } from '../core-state.model';
 import { FindListOptions } from '../data/find-list-options.model';
+import { IdentifiableDataService } from '../data/base/identifiable-data.service';
+import { SearchData, SearchDataImpl } from '../data/base/search-data';
+import { PaginatedList } from '../data/paginated-list.model';
+import { DeleteData, DeleteDataImpl } from '../data/base/delete-data';
+import { NoContent } from '../shared/NoContent.model';
 
 /**
  * A service that provides methods to make REST requests with workspaceitems endpoint.
  */
 @Injectable()
 @dataService(WorkspaceItem.type)
-export class WorkspaceitemDataService extends DataService<WorkspaceItem> {
+export class WorkspaceitemDataService extends IdentifiableDataService<WorkspaceItem> implements SearchData<WorkspaceItem>, DeleteData<WorkspaceItem> {
-  protected linkPath = 'workspaceitems';
   protected searchByItemLinkPath = 'item';
 
+  private searchData: SearchDataImpl<WorkspaceItem>;
+  private deleteData: DeleteDataImpl<WorkspaceItem>;
+
   constructor(
-    protected comparator: DSOChangeAnalyzer<WorkspaceItem>,
-    protected halService: HALEndpointService,
-    protected http: HttpClient,
-    protected notificationsService: NotificationsService,
     protected requestService: RequestService,
     protected rdbService: RemoteDataBuildService,
     protected objectCache: ObjectCacheService,
-    protected store: Store<CoreState>) {
+    protected halService: HALEndpointService,
-    super();
+    protected notificationsService: NotificationsService,
+  ) {
+    super('workspaceitems', requestService, rdbService, objectCache, halService);
+
+    this.searchData = new SearchDataImpl(this.linkPath, requestService, rdbService, objectCache, halService, this.responseMsToLive);
+    this.deleteData = new DeleteDataImpl(this.linkPath, requestService, rdbService, objectCache, halService, notificationsService, this.responseMsToLive, this.constructIdEndpoint);
   }
 
   /**
@@ -57,4 +59,60 @@ export class WorkspaceitemDataService extends DataService<WorkspaceItem> {
     return this.findByHref(href$, 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
+   */
+  public getSearchByHref(searchMethod: string, options?: FindListOptions, ...linksToFollow): 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<WorkspaceItem>[]): Observable<RemoteData<PaginatedList<WorkspaceItem>>> {
+    return this.searchData.searchBy(searchMethod, 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/tasks/claimed-task-data.service.spec.ts

@@ -1,11 +1,8 @@
-import { HttpClient, HttpHeaders } from '@angular/common/http';
+import { HttpHeaders } from '@angular/common/http';
-
-import { Store } from '@ngrx/store';
 
 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 { NotificationsService } from '../../shared/notifications/notifications.service';
 import { ClaimedTaskDataService } from './claimed-task-data.service';
 import { of as observableOf } from 'rxjs/internal/observable/of';
 import { RequestParam } from '../cache/models/request-param.model';
@@ -13,7 +10,6 @@ import { getTestScheduler } from 'jasmine-marbles';
 import { TestScheduler } from 'rxjs/testing';
 import { HttpOptions } from '../dspace-rest/dspace-rest.service';
 import { createSuccessfulRemoteDataObject$ } from '../../shared/remote-data.utils';
-import { CoreState } from '../core-state.model';
 import { FindListOptions } from '../data/find-list-options.model';
 
 describe('ClaimedTaskDataService', () => {
@@ -25,9 +21,6 @@ describe('ClaimedTaskDataService', () => {
   const requestService: any = getMockRequestService();
   const halService: any = new HALEndpointServiceStub(taskEndpoint);
   const rdbService = {} as RemoteDataBuildService;
-  const notificationsService = {} as NotificationsService;
-  const http = {} as HttpClient;
-  const comparator = {} as any;
   const objectCache = {
     addPatch: () => {
       /* empty */
@@ -36,18 +29,13 @@ describe('ClaimedTaskDataService', () => {
       /* empty */
     }
   } as any;
-  const store = {} as Store<CoreState>;
 
   function initTestService(): ClaimedTaskDataService {
     return new ClaimedTaskDataService(
       requestService,
       rdbService,
-      store,
       objectCache,
       halService,
-      notificationsService,
-      http,
-      comparator
     );
   }
 

src/app/core/tasks/claimed-task-data.service.ts

@@ -1,13 +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 { 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 { DSOChangeAnalyzer } from '../data/dso-change-analyzer.service';
 import { RequestService } from '../data/request.service';
 import { HALEndpointService } from '../shared/hal-endpoint.service';
 import { ClaimedTask } from './models/claimed-task-object.model';
@@ -18,7 +14,6 @@ import { RemoteData } from '../data/remote-data';
 import { RequestParam } from '../cache/models/request-param.model';
 import { HttpOptions } from '../dspace-rest/dspace-rest.service';
 import { getFirstSucceededRemoteData } from '../shared/operators';
-import { CoreState } from '../core-state.model';
 import { FindListOptions } from '../data/find-list-options.model';
 
 /**
@@ -28,35 +23,21 @@ import { FindListOptions } from '../data/find-list-options.model';
 @dataService(CLAIMED_TASK)
 export class ClaimedTaskDataService extends TasksService<ClaimedTask> {
 
-  protected responseMsToLive = 1000;
-
-  /**
-   * The endpoint link name
-   */
-  protected linkPath = 'claimedtasks';
-
   /**
    * Initialize instance variables
    *
    * @param {RequestService} requestService
    * @param {RemoteDataBuildService} rdbService
-   * @param {Store<CoreState>} store
    * @param {ObjectCacheService} objectCache
    * @param {HALEndpointService} halService
-   * @param {NotificationsService} notificationsService
-   * @param {HttpClient} http
-   * @param {DSOChangeAnalyzer<ClaimedTask} comparator
    */
   constructor(
     protected requestService: RequestService,
     protected rdbService: RemoteDataBuildService,
-    protected store: Store<CoreState>,
     protected objectCache: ObjectCacheService,
     protected halService: HALEndpointService,
-    protected notificationsService: NotificationsService,
+  ) {
-    protected http: HttpClient,
+    super('claimedtasks', requestService, rdbService, objectCache, halService, 1000);
-    protected comparator: DSOChangeAnalyzer<ClaimedTask>) {
-    super();
   }
 
   /**

src/app/core/tasks/pool-task-data.service.spec.ts

@@ -1,11 +1,8 @@
-import { HttpClient, HttpHeaders } from '@angular/common/http';
+import { HttpHeaders } from '@angular/common/http';
-
-import { Store } from '@ngrx/store';
 
 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 { NotificationsService } from '../../shared/notifications/notifications.service';
 import { PoolTaskDataService } from './pool-task-data.service';
 import { getTestScheduler } from 'jasmine-marbles';
 import { TestScheduler } from 'rxjs/testing';
@@ -13,7 +10,6 @@ import { of as observableOf } from 'rxjs';
 import { RequestParam } from '../cache/models/request-param.model';
 import { HttpOptions } from '../dspace-rest/dspace-rest.service';
 import { createSuccessfulRemoteDataObject$ } from '../../shared/remote-data.utils';
-import { CoreState } from '../core-state.model';
 import { FindListOptions } from '../data/find-list-options.model';
 
 describe('PoolTaskDataService', () => {
@@ -21,13 +17,9 @@ describe('PoolTaskDataService', () => {
   let service: PoolTaskDataService;
   let options: HttpOptions;
   const taskEndpoint = 'https://rest.api/task';
-  const linkPath = 'pooltasks';
   const requestService = getMockRequestService();
   const halService: any = new HALEndpointServiceStub(taskEndpoint);
   const rdbService = {} as RemoteDataBuildService;
-  const notificationsService = {} as NotificationsService;
-  const http = {} as HttpClient;
-  const comparator = {} as any;
   const objectCache = {
     addPatch: () => {
       /* empty */
@@ -36,18 +28,13 @@ describe('PoolTaskDataService', () => {
       /* empty */
     }
   } as any;
-  const store = {} as Store<CoreState>;
 
   function initTestService(): PoolTaskDataService {
     return new PoolTaskDataService(
       requestService,
       rdbService,
-      store,
       objectCache,
       halService,
-      notificationsService,
-      http,
-      comparator
     );
   }
 

src/app/core/tasks/pool-task-data.service.ts

@@ -1,13 +1,9 @@
-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 { DSOChangeAnalyzer } from '../data/dso-change-analyzer.service';
 import { RequestService } from '../data/request.service';
 import { HALEndpointService } from '../shared/hal-endpoint.service';
 import { PoolTask } from './models/pool-task-object.model';
@@ -16,7 +12,6 @@ import { TasksService } from './tasks.service';
 import { RemoteData } from '../data/remote-data';
 import { RequestParam } from '../cache/models/request-param.model';
 import { getFirstCompletedRemoteData } from '../shared/operators';
-import { CoreState } from '../core-state.model';
 import { FindListOptions } from '../data/find-list-options.model';
 
 /**
@@ -25,37 +20,21 @@ import { FindListOptions } from '../data/find-list-options.model';
 @Injectable()
 @dataService(POOL_TASK)
 export class PoolTaskDataService extends TasksService<PoolTask> {
-
-  /**
-   * The endpoint link name
-   */
-  protected linkPath = 'pooltasks';
-
-  protected responseMsToLive = 1000;
-
   /**
    * Initialize instance variables
    *
    * @param {RequestService} requestService
    * @param {RemoteDataBuildService} rdbService
-   * @param {NormalizedObjectBuildService} linkService
-   * @param {Store<CoreState>} store
    * @param {ObjectCacheService} objectCache
    * @param {HALEndpointService} halService
-   * @param {NotificationsService} notificationsService
-   * @param {HttpClient} http
-   * @param {DSOChangeAnalyzer<ClaimedTask} comparator
    */
   constructor(
     protected requestService: RequestService,
     protected rdbService: RemoteDataBuildService,
-    protected store: Store<CoreState>,
     protected objectCache: ObjectCacheService,
     protected halService: HALEndpointService,
-    protected notificationsService: NotificationsService,
+  ) {
-    protected http: HttpClient,
+    super('pooltasks', requestService, rdbService, objectCache, halService, 1000);
-    protected comparator: DSOChangeAnalyzer<PoolTask>) {
-    super();
   }
 
   /**