followlinks

src/app/+collection-page/collection-page.resolver.ts

@@ -6,6 +6,7 @@ import { CollectionDataService } from '../core/data/collection-data.service';
 import { RemoteData } from '../core/data/remote-data';
 import { find } from 'rxjs/operators';
 import { hasValue } from '../shared/empty.util';
+import { followLink } from '../shared/utils/follow-link-config.model';
 
 /**
  * This class represents a resolver that requests a specific collection before the route is activated
@@ -23,7 +24,7 @@ export class CollectionPageResolver implements Resolve<RemoteData<Collection>> {
    * or an error if something went wrong
    */
   resolve(route: ActivatedRouteSnapshot, state: RouterStateSnapshot): Observable<RemoteData<Collection>> {
-    return this.collectionService.findById(route.params.id).pipe(
+    return this.collectionService.findById(route.params.id, followLink('logo')).pipe(
       find((RD) => hasValue(RD.error) || RD.hasSucceeded),
     );
   }

src/app/+community-page/community-page.resolver.ts

@@ -6,6 +6,7 @@ import { Community } from '../core/shared/community.model';
 import { CommunityDataService } from '../core/data/community-data.service';
 import { find } from 'rxjs/operators';
 import { hasValue } from '../shared/empty.util';
+import { followLink } from '../shared/utils/follow-link-config.model';
 
 /**
  * This class represents a resolver that requests a specific community before the route is activated
@@ -23,7 +24,12 @@ export class CommunityPageResolver implements Resolve<RemoteData<Community>> {
    * or an error if something went wrong
    */
   resolve(route: ActivatedRouteSnapshot, state: RouterStateSnapshot): Observable<RemoteData<Community>> {
-    return this.communityService.findById(route.params.id).pipe(
+    return this.communityService.findById(
+      route.params.id,
+      followLink('logo'),
+      followLink('subcommunities'),
+      followLink('collections')
+    ).pipe(
       find((RD) => hasValue(RD.error) || RD.hasSucceeded)
     );
   }

src/app/+item-page/full/field-components/file-section/full-file-section.component.ts

@@ -1,12 +1,12 @@
 import { Component, Injector, Input, OnInit } from '@angular/core';
 import { combineLatest as observableCombineLatest, Observable } from 'rxjs';
 import { map, startWith } from 'rxjs/operators';
-import { getBitstreamBuilder } from '../../../../core/cache/builders/bitstream-builder';
 import { BitstreamDataService } from '../../../../core/data/bitstream-data.service';
 
 import { Bitstream } from '../../../../core/shared/bitstream.model';
 import { Item } from '../../../../core/shared/item.model';
 import { getFirstSucceededRemoteListPayload } from '../../../../core/shared/operators';
+import { followLink } from '../../../../shared/utils/follow-link-config.model';
 import { FileSectionComponent } from '../../../simple/field-components/file-section/file-section.component';
 
 /**
@@ -28,8 +28,7 @@ export class FullFileSectionComponent extends FileSectionComponent implements On
   bitstreams$: Observable<Bitstream[]>;
 
   constructor(
-    bitstreamDataService: BitstreamDataService,
+    bitstreamDataService: BitstreamDataService
-    private parentInjector: Injector
   ) {
     super(bitstreamDataService);
   }
@@ -40,11 +39,21 @@ export class FullFileSectionComponent extends FileSectionComponent implements On
 
   initialize(): void {
     // TODO pagination
-    const originals$ = this.bitstreamDataService.findAllByItemAndBundleName(this.item, 'ORIGINAL', { elementsPerPage: Number.MAX_SAFE_INTEGER }).pipe(
+    const originals$ = this.bitstreamDataService.findAllByItemAndBundleName(
+      this.item,
+      'ORIGINAL',
+      { elementsPerPage: Number.MAX_SAFE_INTEGER },
+      followLink( 'format')
+    ).pipe(
       getFirstSucceededRemoteListPayload(),
       startWith([])
     );
-    const licenses$ = this.bitstreamDataService.findAllByItemAndBundleName(this.item, 'LICENSE', { elementsPerPage: Number.MAX_SAFE_INTEGER }).pipe(
+    const licenses$ = this.bitstreamDataService.findAllByItemAndBundleName(
+      this.item,
+      'LICENSE',
+      { elementsPerPage: Number.MAX_SAFE_INTEGER },
+      followLink( 'format')
+    ).pipe(
       getFirstSucceededRemoteListPayload(),
       startWith([])
     );
@@ -53,10 +62,8 @@ export class FullFileSectionComponent extends FileSectionComponent implements On
       map((files: Bitstream[]) =>
         files.map(
           (original) => {
-            return getBitstreamBuilder(this.parentInjector, original)
+            original.thumbnail = this.bitstreamDataService.getMatchingThumbnail(this.item, original);
-              .loadThumbnail(this.item)
+            return original;
-              .loadBitstreamFormat()
-              .build();
           }
         )
       )

src/app/+item-page/item-page.resolver.ts

@@ -6,6 +6,7 @@ import { ItemDataService } from '../core/data/item-data.service';
 import { Item } from '../core/shared/item.model';
 import { hasValue } from '../shared/empty.util';
 import { find } from 'rxjs/operators';
+import { followLink } from '../shared/utils/follow-link-config.model';
 
 /**
  * This class represents a resolver that requests a specific item before the route is activated
@@ -23,9 +24,12 @@ export class ItemPageResolver implements Resolve<RemoteData<Item>> {
    * or an error if something went wrong
    */
   resolve(route: ActivatedRouteSnapshot, state: RouterStateSnapshot): Observable<RemoteData<Item>> {
-    return this.itemService.findById(route.params.id)
+    return this.itemService.findById(route.params.id,
-      .pipe(
+      followLink('owningCollection'),
-        find((RD) => hasValue(RD.error) || RD.hasSucceeded),
+      followLink('bundles'),
-      );
+      followLink('relationships')
+    ).pipe(
+      find((RD) => hasValue(RD.error) || RD.hasSucceeded),
+    );
   }
 }

src/app/+lookup-by-id/lookup-guard.spec.ts

@@ -14,7 +14,7 @@ describe('LookupGuard', () => {
     guard = new LookupGuard(dsoService);
   });
 
-  it('should call findById with handle params', () => {
+  it('should call findByIdAndIDType with handle params', () => {
     const scopedRoute = {
       params: {
         id: '1234',
@@ -25,7 +25,7 @@ describe('LookupGuard', () => {
     expect(dsoService.findById).toHaveBeenCalledWith('123456789/1234', IdentifierType.HANDLE)
   });
 
-  it('should call findById with handle params', () => {
+  it('should call findByIdAndIDType with handle params', () => {
     const scopedRoute = {
       params: {
         id: '123456789%2F1234',
@@ -36,7 +36,7 @@ describe('LookupGuard', () => {
     expect(dsoService.findById).toHaveBeenCalledWith('123456789%2F1234', IdentifierType.HANDLE)
   });
 
-  it('should call findById with UUID params', () => {
+  it('should call findByIdAndIDType with UUID params', () => {
     const scopedRoute = {
       params: {
         id: '34cfed7c-f597-49ef-9cbe-ea351f0023c2',

src/app/+lookup-by-id/lookup-guard.ts

@@ -20,7 +20,7 @@ export class LookupGuard implements CanActivate {
 
   canActivate(route: ActivatedRouteSnapshot, state: RouterStateSnapshot): Observable<boolean>  {
     const params = this.getLookupParams(route);
-    return this.dsoService.findById(params.id, params.type).pipe(
+    return this.dsoService.findByIdAndIDType(params.id, params.type).pipe(
       map((response: RemoteData<FindByIDRequest>) => response.hasFailed)
     );
   }

src/app/core/auth/models/auth-status.model.ts

@@ -1,3 +1,4 @@
+import { HALLink } from '../../shared/hal-link.model';
 import { AuthError } from './auth-error.model';
 import { AuthTokenInfo } from './auth-token-info.model';
 import { EPerson } from '../../eperson/models/eperson.model';
@@ -51,4 +52,8 @@ export class AuthStatus implements CacheableObject {
    * The self link of this auth status' REST object
    */
   self: string;
+
+  _links: {
+    self: HALLink;
+  }
 }

src/app/core/cache/builders/bitstream-builder.ts

@@ -1,60 +0,0 @@
-import { Injector } from '@angular/core';
-import { Observable } from 'rxjs/internal/Observable';
-import { BitstreamDataService } from '../../data/bitstream-data.service';
-import { BitstreamFormatDataService } from '../../data/bitstream-format-data.service';
-import { RemoteData } from '../../data/remote-data';
-import { BitstreamFormat } from '../../shared/bitstream-format.model';
-import { Bitstream } from '../../shared/bitstream.model';
-import { Item } from '../../shared/item.model';
-
-export const getBitstreamBuilder = (parentInjector: Injector, bitstream: Bitstream) => {
-  const injector = Injector.create({
-    providers:[
-      {
-        provide: BitstreamBuilder,
-        useClass: BitstreamBuilder,
-        deps:[
-          BitstreamDataService,
-          BitstreamFormatDataService,
-        ]
-      }
-    ],
-    parent: parentInjector
-  });
-  return injector.get(BitstreamBuilder).initWithBitstream(bitstream);
-};
-
-export class BitstreamBuilder {
-  private bitstream: Bitstream;
-  private thumbnail: Observable<RemoteData<Bitstream>>;
-  private format: Observable<RemoteData<BitstreamFormat>>;
-
-  constructor(
-    protected bitstreamDataService: BitstreamDataService,
-    protected bitstreamFormatDataService: BitstreamFormatDataService
-  ) {
-  }
-
-  initWithBitstream(bitstream: Bitstream): BitstreamBuilder {
-    this.bitstream = bitstream;
-    return this;
-  }
-
-  loadThumbnail(item: Item): BitstreamBuilder {
-    this.thumbnail = this.bitstreamDataService.getMatchingThumbnail(item, this.bitstream);
-    return this;
-  }
-
-  loadBitstreamFormat(): BitstreamBuilder {
-    this.format = this.bitstreamFormatDataService.findByBitstream(this.bitstream);
-    return this;
-  }
-
-  build(): Bitstream {
-    const bitstream = this.bitstream;
-    bitstream.thumbnail = this.thumbnail;
-    bitstream.format = this.format;
-    return bitstream;
-  }
-
-}

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

@@ -1,14 +1,22 @@
 import 'reflect-metadata';
+import { hasNoValue, hasValue } from '../../../shared/empty.util';
+import { DataService } from '../../data/data.service';
+import { PaginatedList } from '../../data/paginated-list';
 
 import { GenericConstructor } from '../../shared/generic-constructor';
+import { HALResource } from '../../shared/hal-resource.model';
 import { CacheableObject, TypedObject } from '../object-cache.reducer';
 import { ResourceType } from '../../shared/resource-type';
 
 const mapsToMetadataKey = Symbol('mapsTo');
 const relationshipKey = Symbol('relationship');
+const resolvedLinkKey = Symbol('resolvedLink');
 
 const relationshipMap = new Map();
+const resolvedLinkMap = new Map();
 const typeMap = new Map();
+const dataServiceMap = new Map();
+const linkMap = new Map();
 
 /**
  * Decorator function to map a normalized class to it's not-normalized counter part class
@@ -79,3 +87,94 @@ export function getRelationMetadata(target: any, propertyKey: string) {
 export function getRelationships(target: any) {
   return relationshipMap.get(target);
 }
+
+export function dataService<T extends CacheableObject>(domainModelConstructor: GenericConstructor<T>): any {
+  return (target: any) => {
+    if (hasNoValue(domainModelConstructor)) {
+      throw new Error(`Invalid @dataService annotation on ${target}, domainModelConstructor needs to be defined`);
+    }
+    const existingDataservice = dataServiceMap.get(domainModelConstructor);
+
+    if (hasValue(existingDataservice)) {
+      throw new Error(`Multiple dataservices for ${domainModelConstructor}: ${existingDataservice} and ${target}`);
+    }
+
+    dataServiceMap.set(domainModelConstructor, target);
+  };
+}
+
+export function getDataServiceFor<T extends CacheableObject>(domainModelConstructor: GenericConstructor<T>) {
+  return dataServiceMap.get(domainModelConstructor);
+}
+
+export function resolvedLink<T extends DataService<any>, K extends keyof T>(provider: GenericConstructor<T>, methodName?: K, ...params: any[]): any {
+  return function r(target: any, propertyKey: string, descriptor: PropertyDescriptor) {
+    if (!target || !propertyKey) {
+      return;
+    }
+
+    const metaDataList: string[] = resolvedLinkMap.get(target.constructor) || [];
+    if (metaDataList.indexOf(propertyKey) === -1) {
+      metaDataList.push(propertyKey);
+    }
+    resolvedLinkMap.set(target.constructor, metaDataList);
+    return Reflect.metadata(resolvedLinkKey, {
+      provider,
+      methodName,
+      params
+    }).apply(this, arguments);
+  };
+}
+
+export function getResolvedLinkMetadata(target: any, propertyKey: string) {
+  return Reflect.getMetadata(resolvedLinkKey, target, propertyKey);
+}
+
+export function getResolvedLinks(target: any) {
+  return resolvedLinkMap.get(target);
+}
+
+export class LinkDefinition<T extends HALResource> {
+  targetConstructor: GenericConstructor<CacheableObject>;
+  isList = false;
+  linkName?: keyof T['_links'];
+}
+
+export const link = <T extends HALResource>(
+  targetConstructor: GenericConstructor<HALResource>,
+  isList = false,
+  linkName?: keyof T['_links'],
+  ) => {
+  return (target: T, key: string) => {
+    let targetMap = linkMap.get(target.constructor);
+
+    if (hasNoValue(targetMap)) {
+      targetMap = new Map<keyof T['_links'],LinkDefinition<T>>();
+    }
+
+    if (hasNoValue(linkName)) {
+      linkName = key;
+    }
+
+    targetMap.set(key, {
+      targetConstructor,
+      isList,
+      linkName
+    });
+
+    linkMap.set(target.constructor, targetMap);
+  }
+};
+
+export const getLinks = <T extends HALResource>(source: GenericConstructor<T>): Map<keyof T['_links'], LinkDefinition<T>> => {
+  return linkMap.get(source);
+};
+
+export const getLink = <T extends HALResource>(source: GenericConstructor<T>, linkName: keyof T['_links']): LinkDefinition<T> => {
+  const sourceMap = linkMap.get(source);
+  if (hasValue(sourceMap)) {
+    return sourceMap.get(linkName);
+  } else {
+    return undefined;
+  }
+};

src/app/core/cache/builders/collection-builder.ts

@@ -0,0 +1,74 @@
+import { Injector } from '@angular/core';
+import { Observable } from 'rxjs/internal/Observable';
+import { BitstreamDataService } from '../../data/bitstream-data.service';
+import { CollectionDataService } from '../../data/collection-data.service';
+import { PaginatedList } from '../../data/paginated-list';
+import { RemoteData } from '../../data/remote-data';
+import { ResourcePolicyService } from '../../data/resource-policy.service';
+import { Bitstream } from '../../shared/bitstream.model';
+import { Collection } from '../../shared/collection.model';
+import { Item } from '../../shared/item.model';
+import { ResourcePolicy } from '../../shared/resource-policy.model';
+
+export const getCollectionBuilder = (parentInjector: Injector, collection: Collection) => {
+  const injector = Injector.create({
+    providers:[
+      {
+        provide: CollectionBuilder,
+        useClass: CollectionBuilder,
+        deps:[
+          CollectionDataService
+        ]
+      }
+    ],
+    parent: parentInjector
+  });
+  return injector.get(CollectionBuilder).initWithCollection(collection);
+};
+
+export class CollectionBuilder {
+  private collection: Collection;
+  private logo: Observable<RemoteData<Bitstream>>;
+  // private license: Observable<RemoteData<License>>;
+  private defaultAccessConditions: Observable<RemoteData<PaginatedList<ResourcePolicy>>>;
+
+  constructor(
+    protected collectionDataService: CollectionDataService,
+    protected bitstreamDataService: BitstreamDataService,
+    protected resourcePolicyService: ResourcePolicyService,
+  ) {
+  }
+
+  initWithCollection(collection: Collection): CollectionBuilder {
+    this.collection = collection;
+    return this;
+  }
+
+  loadLogo(item: Item): CollectionBuilder {
+    // this.logo = this.bitstreamDataService.getLogoFor(this.collection);
+    return this;
+  }
+
+  loadDefaultAccessConditions(item: Item): CollectionBuilder {
+    this.defaultAccessConditions = this.resourcePolicyService.getDefaultAccessConditionsFor(this.collection);
+    return this;
+  }
+
+  /**
+   * As far as I can tell, the rest api doesn't support licenses yet.
+   * So I'm keeping this commented out
+   */
+  // loadLicense(): CollectionBuilder {
+  //   this.license = this.bitstreamDataService.getLicenseFor(this.collection);
+  //   return this;
+  // }
+
+  build(): Collection {
+    const collection = this.collection;
+    collection.logo = this.logo;
+    // collection.license = this.license;
+    collection.defaultAccessConditions = this.defaultAccessConditions;
+    return collection;
+  }
+
+}

src/app/core/cache/builders/remote-data-build.service.ts

@@ -1,4 +1,4 @@
-import { Injectable } from '@angular/core';
+import { Injectable, Injector } from '@angular/core';
 
 import {
   combineLatest as observableCombineLatest,
@@ -16,16 +16,24 @@ import {
   isNotEmpty,
   isNotUndefined
 } from '../../../shared/empty.util';
+import { FollowLinkConfig } from '../../../shared/utils/follow-link-config.model';
 import { PaginatedList } from '../../data/paginated-list';
 import { RemoteData } from '../../data/remote-data';
 import { RemoteDataError } from '../../data/remote-data-error';
 import { GetRequest } from '../../data/request.models';
 import { RequestEntry } from '../../data/request.reducer';
 import { RequestService } from '../../data/request.service';
+import { HALResource } from '../../shared/hal-resource.model';
 import { NormalizedObject } from '../models/normalized-object.model';
 import { ObjectCacheService } from '../object-cache.service';
 import { DSOSuccessResponse, ErrorResponse } from '../response.models';
-import { getMapsTo, getRelationMetadata, getRelationships } from './build-decorators';
+import {
+  getDataServiceFor, getLink,
+  getLinks,
+  getMapsTo,
+  getRelationMetadata,
+  getRelationships
+} from './build-decorators';
 import { PageInfo } from '../../shared/page-info.model';
 import {
   filterSuccessfulResponses,
@@ -39,10 +47,11 @@ import { createSuccessfulRemoteDataObject$ } from '../../../shared/testing/utils
 @Injectable()
 export class RemoteDataBuildService {
   constructor(protected objectCache: ObjectCacheService,
+              private parentInjector: Injector,
               protected requestService: RequestService) {
   }
 
-  buildSingle<T extends CacheableObject>(href$: string | Observable<string>): Observable<RemoteData<T>> {
+  buildSingle<T extends CacheableObject>(href$: string | Observable<string>, ...linksToFollow: Array<FollowLinkConfig<T>>): Observable<RemoteData<T>> {
     if (typeof href$ === 'string') {
       href$ = observableOf(href$);
     }
@@ -83,7 +92,7 @@ export class RemoteDataBuildService {
         }),
         hasValueOperator(),
         map((normalized: NormalizedObject<T>) => {
-          return this.build<T>(normalized);
+          return this.build<T>(normalized, ...linksToFollow);
         }),
         startWith(undefined),
         distinctUntilChanged()
@@ -120,7 +129,7 @@ export class RemoteDataBuildService {
     );
   }
 
-  buildList<T extends CacheableObject>(href$: string | Observable<string>): Observable<RemoteData<PaginatedList<T>>> {
+  buildList<T extends CacheableObject>(href$: string | Observable<string>, ...linksToFollow: Array<FollowLinkConfig<T>>): Observable<RemoteData<PaginatedList<T>>> {
     if (typeof href$ === 'string') {
       href$ = observableOf(href$);
     }
@@ -132,7 +141,7 @@ export class RemoteDataBuildService {
         return this.objectCache.getList(resourceUUIDs).pipe(
           map((normList: Array<NormalizedObject<T>>) => {
             return normList.map((normalized: NormalizedObject<T>) => {
-              return this.build<T>(normalized);
+              return this.build<T>(normalized, ...linksToFollow);
             });
           }));
       }),
@@ -162,8 +171,8 @@ export class RemoteDataBuildService {
     return this.toRemoteDataObservable(requestEntry$, payload$);
   }
 
-  build<T extends CacheableObject>(normalized: NormalizedObject<T>): T {
+  build<T extends CacheableObject>(normalized: NormalizedObject<T>, ...linksToFollow: Array<FollowLinkConfig<T>>): T {
-    const links: any = {};
+    const halLinks: any = {};
     const relationships = getRelationships(normalized.constructor) || [];
 
     relationships.forEach((relationship: string) => {
@@ -207,22 +216,61 @@ export class RemoteDataBuildService {
           }
 
           if (hasValue(normalized[relationship].page)) {
-            links[relationship] = this.toPaginatedList(result, normalized[relationship].pageInfo);
+            halLinks[relationship] = this.toPaginatedList(result, normalized[relationship].pageInfo);
           } else {
-            links[relationship] = result;
+            halLinks[relationship] = result;
           }
         } else {
-          if (hasNoValue(links._links)) {
+          if (hasNoValue(halLinks._links)) {
-            links._links = {};
+            halLinks._links = {};
           }
-          links._links[relationship] = {
+          halLinks._links[relationship] = {
             href: objectList
           };
         }
       }
     });
-    const domainModel = getMapsTo(normalized.constructor);
+    const domainModelConstructor = getMapsTo(normalized.constructor);
-    return Object.assign(new domainModel(), normalized, links);
+    const domainModel = Object.assign(new domainModelConstructor(), normalized, halLinks);
+
+    linksToFollow.forEach((linkToFollow: FollowLinkConfig<T>) => {
+      this.resolveLink(domainModel, linkToFollow);
+    });
+
+    console.log('domainModel._links', domainModel._links);
+
+    return domainModel;
+  }
+
+  public resolveLink<T extends HALResource>(model, linkToFollow: FollowLinkConfig<T>) {
+    console.log('resolveLink', model, linkToFollow);
+
+    const matchingLink = getLink(model.constructor, linkToFollow.name);
+
+    if (hasNoValue(matchingLink)) {
+      throw new Error(`followLink('${linkToFollow.name}') was used for a ${model.constructor.name}, but there is no property on ${model.constructor.name} models with an @link() for ${linkToFollow.name}`);
+    } else {
+      const provider = getDataServiceFor(matchingLink.targetConstructor);
+
+      if (hasNoValue(provider)) {
+        throw new Error(`The @link() for ${linkToFollow.name} on ${model.constructor.name} models refers to a ${matchingLink.targetConstructor.name}, but there is no service with an @dataService(${matchingLink.targetConstructor.name}) annotation in order to retrieve it`);
+      }
+
+      const service = Injector.create({
+        providers: [],
+        parent: this.parentInjector
+      }).get(provider);
+
+      const href = model._links[matchingLink.linkName].href;
+
+      if (matchingLink.isList) {
+        model[linkToFollow.name] =  service.findAllByHref(href, linkToFollow.findListOptions, ...linkToFollow.linksToFollow);
+      } else {
+        model[linkToFollow.name] =  service.findByHref(href, ...linkToFollow.linksToFollow);
+      }
+
+      console.log(`model['${linkToFollow.name}']`, model[linkToFollow.name]);
+    }
   }
 
   aggregate<T>(input: Array<Observable<RemoteData<T>>>): Observable<RemoteData<T[]>> {

src/app/core/cache/models/normalized-community.model.ts

@@ -25,32 +25,32 @@ export class NormalizedCommunity extends NormalizedDSpaceObject<Community> {
    * The Bitstream that represents the logo of this Community
    */
   @deserialize
-  @relationship(Bitstream, false)
+  @relationship(Bitstream, false, false)
   logo: string;
 
   /**
    * An array of Communities that are direct parents of this Community
    */
   @deserialize
-  @relationship(Community, true)
+  @relationship(Community, true, false)
   parents: string[];
 
   /**
    * The Community that owns this Community
    */
   @deserialize
-  @relationship(Community, false)
+  @relationship(Community, false, false)
   owner: string;
 
   /**
    * List of Collections that are owned by this Community
    */
   @deserialize
-  @relationship(Collection, true)
+  @relationship(Collection, true, false)
   collections: string[];
 
   @deserialize
-  @relationship(Community, true)
+  @relationship(Community, true, false)
   subcommunities: string[];
 
 }

src/app/core/cache/models/normalized-dspace-object.model.ts

@@ -1,5 +1,6 @@
 import { autoserializeAs, deserializeAs, autoserialize } from 'cerialize';
 import { DSpaceObject } from '../../shared/dspace-object.model';
+import { HALLink } from '../../shared/hal-link.model';
 import { MetadataMap, MetadataMapSerializer } from '../../shared/metadata.models';
 import { mapsTo } from '../builders/build-decorators';
 import { NormalizedObject } from './normalized-object.model';
@@ -67,6 +68,7 @@ export class NormalizedDSpaceObject<T extends DSpaceObject> extends NormalizedOb
    */
   @deserializeAs(Object)
   _links: {
-    [name: string]: string
+    self: HALLink,
+    [name: string]: HALLink
   }
 }

src/app/core/cache/models/normalized-item.model.ts

@@ -44,13 +44,6 @@ export class NormalizedItem extends NormalizedDSpaceObject<Item> {
   @autoserializeAs(Boolean, 'withdrawn')
   isWithdrawn: boolean;
 
-  /**
-   * An array of Collections that are direct parents of this Item
-   */
-  @deserialize
-  @relationship(Collection, true, false)
-  parents: string[];
-
   /**
    * The Collection that owns this Item
    */

src/app/core/cache/models/normalized-object.model.ts

@@ -1,3 +1,4 @@
+import { HALLink } from '../../shared/hal-link.model';
 import { CacheableObject, TypedObject } from '../object-cache.reducer';
 import { autoserialize, deserialize } from 'cerialize';
 import { ResourceType } from '../../shared/resource-type';
@@ -13,7 +14,8 @@ export abstract class NormalizedObject<T extends TypedObject> implements Cacheab
 
   @deserialize
   _links: {
-    [name: string]: string
+    self: HALLink,
+    [name: string]: HALLink
   };
 
   /**

src/app/core/cache/object-cache.reducer.ts

@@ -1,3 +1,5 @@
+import { HALLink } from '../shared/hal-link.model';
+import { HALResource } from '../shared/hal-resource.model';
 import {
   ObjectCacheAction,
   ObjectCacheActionTypes,
@@ -42,10 +44,14 @@ export abstract class TypedObject {
  *
  * A cacheable object should have a self link
  */
-export class CacheableObject extends TypedObject {
+export class CacheableObject extends TypedObject implements HALResource {
   uuid?: string;
   handle?: string;
   self: string;
+
+  _links: {
+    self: HALLink;
+  }
   // isNew: boolean;
   // dirtyType: DirtyType;
   // hasDirtyAttributes: boolean;

src/app/core/config/models/config.model.ts

@@ -1,4 +1,5 @@
 import { CacheableObject } from '../../cache/object-cache.reducer';
+import { HALLink } from '../../shared/hal-link.model';
 import { ResourceType } from '../../shared/resource-type';
 
 export abstract class ConfigObject implements CacheableObject {
@@ -11,8 +12,9 @@ export abstract class ConfigObject implements CacheableObject {
   /**
    * The links to all related resources returned by the rest api.
    */
-  public _links: {
+  _links: {
-    [name: string]: string
+    self: HALLink,
+    [name: string]: HALLink
   };
 
   /**

src/app/core/config/models/normalized-config.model.ts

@@ -1,6 +1,7 @@
 import { autoserialize, inheritSerialization } from 'cerialize';
 import { NormalizedObject } from '../../cache/models/normalized-object.model';
 import { CacheableObject, TypedObject } from '../../cache/object-cache.reducer';
+import { HALLink } from '../../shared/hal-link.model';
 import { ResourceType } from '../../shared/resource-type';
 
 /**
@@ -20,7 +21,8 @@ export abstract class NormalizedConfigObject<T extends CacheableObject> implemen
    */
   @autoserialize
   public _links: {
-    [name: string]: string
+    self: HALLink,
+    [name: string]: HALLink
   };
 
   /**

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

@@ -5,6 +5,8 @@ import { Observable } from 'rxjs/internal/Observable';
 import { map, switchMap } from 'rxjs/operators';
 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 { NormalizedObjectBuildService } from '../cache/builders/normalized-object-build.service';
 import { RemoteDataBuildService } from '../cache/builders/remote-data-build.service';
 import { ObjectCacheService } from '../cache/object-cache.service';
@@ -26,6 +28,7 @@ import { RequestService } from './request.service';
 @Injectable({
   providedIn: 'root'
 })
+@dataService(Bitstream)
 export class BitstreamDataService extends DataService<Bitstream> {
 
   protected linkPath = 'bitstreams';
@@ -57,8 +60,8 @@ export class BitstreamDataService extends DataService<Bitstream> {
    * @param bundle the bundle to retrieve bitstreams from
    * @param options options for the find all request
    */
-  findAllByBundle(bundle: Bundle, options?: FindListOptions): Observable<RemoteData<PaginatedList<Bitstream>>> {
+  findAllByBundle(bundle: Bundle, options?: FindListOptions, ...linksToFollow: Array<FollowLinkConfig<Bitstream>>): Observable<RemoteData<PaginatedList<Bitstream>>> {
-    return this.findAllByHref(bundle._links.bitstreams.href, options);
+    return this.findAllByHref(bundle._links.bitstreams.href, options, ...linksToFollow);
   }
 
   /**
@@ -132,11 +135,11 @@ export class BitstreamDataService extends DataService<Bitstream> {
     );
   }
 
-  public findAllByItemAndBundleName(item: Item, bundleName: string, options?: FindListOptions): Observable<RemoteData<PaginatedList<Bitstream>>> {
+  public findAllByItemAndBundleName(item: Item, bundleName: string, options?: FindListOptions, ...linksToFollow: Array<FollowLinkConfig<Bitstream>>): Observable<RemoteData<PaginatedList<Bitstream>>> {
     return this.bundleService.findByItemAndName(item, bundleName).pipe(
       switchMap((bundleRD: RemoteData<Bundle>) => {
         if (hasValue(bundleRD.payload)) {
-          return this.findAllByBundle(bundleRD.payload, options);
+          return this.findAllByBundle(bundleRD.payload, options, ...linksToFollow);
         } else {
           return [bundleRD as any];
         }

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

@@ -1,4 +1,5 @@
 import { Injectable } from '@angular/core';
+import { dataService } from '../cache/builders/build-decorators';
 import { Bitstream } from '../shared/bitstream.model';
 import { DataService } from './data.service';
 import { BitstreamFormat } from '../shared/bitstream-format.model';
@@ -40,6 +41,7 @@ const selectedBitstreamFormatSelector = createSelector(bitstreamFormatsStateSele
  * A service responsible for fetching/sending data from/to the REST API on the bitstreamformats endpoint
  */
 @Injectable()
+@dataService(BitstreamFormat)
 export class BitstreamFormatDataService extends DataService<BitstreamFormat> {
 
   protected linkPath = 'bitstreamformats';

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

@@ -5,6 +5,8 @@ import { Observable } from 'rxjs/internal/Observable';
 import { map } 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 { NormalizedObjectBuildService } from '../cache/builders/normalized-object-build.service';
 import { RemoteDataBuildService } from '../cache/builders/remote-data-build.service';
 import { ObjectCacheService } from '../cache/object-cache.service';
@@ -26,6 +28,7 @@ import { RequestService } from './request.service';
 @Injectable(
   {providedIn: 'root'}
 )
+@dataService(Bundle)
 export class BundleDataService extends DataService<Bundle> {
   protected linkPath = 'bundles';
   protected forceBypassCache = false;
@@ -52,13 +55,13 @@ export class BundleDataService extends DataService<Bundle> {
     return this.halService.getEndpoint(this.linkPath);
   }
 
-  findAllByItem(item: Item, options?: FindListOptions): Observable<RemoteData<PaginatedList<Bundle>>> {
+  findAllByItem(item: Item, options?: FindListOptions, ...linksToFollow: Array<FollowLinkConfig<Bundle>>): Observable<RemoteData<PaginatedList<Bundle>>> {
-    return this.findAllByHref(item._links.bundles.href, options);
+    return this.findAllByHref(item._links.bundles.href, options,  ...linksToFollow);
   }
 
   // TODO should be implemented rest side
-  findByItemAndName(item: Item, bundleName: string): Observable<RemoteData<Bundle>> {
+  findByItemAndName(item: Item, bundleName: string, ...linksToFollow: Array<FollowLinkConfig<Bundle>>): Observable<RemoteData<Bundle>> {
-    return this.findAllByItem(item, { elementsPerPage: Number.MAX_SAFE_INTEGER }).pipe(
+    return this.findAllByItem(item, { elementsPerPage: Number.MAX_SAFE_INTEGER }, ...linksToFollow).pipe(
       map((rd: RemoteData<PaginatedList<Bundle>>) => {
         if (hasValue(rd.payload) && hasValue(rd.payload.page)) {
           const matchingBundle = rd.payload.page.find((bundle: Bundle) =>

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

@@ -2,6 +2,7 @@ import { Injectable } from '@angular/core';
 
 import { distinctUntilChanged, filter, map, switchMap, take } from 'rxjs/operators';
 import { Store } from '@ngrx/store';
+import { dataService } from '../cache/builders/build-decorators';
 
 import { RemoteDataBuildService } from '../cache/builders/remote-data-build.service';
 import { ObjectCacheService } from '../cache/object-cache.service';
@@ -48,6 +49,7 @@ import { INotification } from '../../shared/notifications/models/notification.mo
 import { PaginatedSearchOptions } from '../../shared/search/paginated-search-options.model';
 
 @Injectable()
+@dataService(Collection)
 export class CollectionDataService extends ComColDataService<Collection> {
   protected linkPath = 'collections';
   protected errorTitle = 'collection.source.update.notifications.error.title';

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

@@ -8,6 +8,7 @@ import { merge as observableMerge, Observable, throwError as observableThrowErro
 import { hasValue, isEmpty, isNotEmpty } from '../../shared/empty.util';
 import { NormalizedCommunity } from '../cache/models/normalized-community.model';
 import { ObjectCacheService } from '../cache/object-cache.service';
+import { HALLink } from '../shared/hal-link.model';
 import { CommunityDataService } from './community-data.service';
 
 import { DataService } from './data.service';
@@ -71,7 +72,8 @@ export abstract class ComColDataService<T extends CacheableObject> extends DataS
         filter((response) => response.isSuccessful),
         mergeMap(() => this.objectCache.getObjectByUUID(options.scopeID)),
         map((nc: NormalizedCommunity) => nc._links[linkPath]),
-        filter((href) => isNotEmpty(href))
+        filter((halLink: HALLink) => isNotEmpty(halLink)),
+        map((halLink: HALLink) => halLink.href)
       );
 
       return observableMerge(errorResponses, successResponses).pipe(distinctUntilChanged(), share());

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

@@ -2,6 +2,7 @@ import { filter, switchMap, take } from 'rxjs/operators';
 import { Injectable } from '@angular/core';
 
 import { Store } from '@ngrx/store';
+import { dataService } from '../cache/builders/build-decorators';
 import { RemoteDataBuildService } from '../cache/builders/remote-data-build.service';
 import { ObjectCacheService } from '../cache/object-cache.service';
 import { CoreState } from '../core.reducers';
@@ -20,6 +21,7 @@ import { NormalizedObjectBuildService } from '../cache/builders/normalized-objec
 import { DSOChangeAnalyzer } from './dso-change-analyzer.service';
 
 @Injectable()
+@dataService(Community)
 export class CommunityDataService extends ComColDataService<Community> {
   protected linkPath = 'communities';
   protected topLinkPath = 'communities/search/top';

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

@@ -16,6 +16,7 @@ import {
 import { Store } from '@ngrx/store';
 
 import { hasValue, isNotEmpty, isNotEmptyOperator } from '../../shared/empty.util';
+import { FollowLinkConfig } from '../../shared/utils/follow-link-config.model';
 import { RemoteDataBuildService } from '../cache/builders/remote-data-build.service';
 import { HALEndpointService } from '../shared/hal-endpoint.service';
 import { URLCombiner } from '../url-combiner/url-combiner';
@@ -30,7 +31,6 @@ import {
   GetRequest
 } from './request.models';
 import { RequestService } from './request.service';
-import { HttpOptions } from '../dspace-rest-v2/dspace-rest-v2.service';
 import { NormalizedObject } from '../cache/models/normalized-object.model';
 import { SearchParam } from '../cache/models/search-param.model';
 import { Operation } from 'fast-json-patch';
@@ -140,11 +140,11 @@ export abstract class DataService<T extends CacheableObject> {
     }
   }
 
-  findAll(options: FindListOptions = {}): Observable<RemoteData<PaginatedList<T>>> {
+  findAll(options: FindListOptions = {}, ...linksToFollow: Array<FollowLinkConfig<T>>): Observable<RemoteData<PaginatedList<T>>> {
-    return this.findList(this.getFindAllHref(options), options);
+    return this.findList(this.getFindAllHref(options), options, ...linksToFollow);
   }
 
-  protected findList(href$, options: FindListOptions) {
+  protected findList(href$, options: FindListOptions, ...linksToFollow: Array<FollowLinkConfig<T>>) {
     href$.pipe(
       first((href: string) => hasValue(href)))
       .subscribe((href: string) => {
@@ -155,7 +155,7 @@ export abstract class DataService<T extends CacheableObject> {
         this.requestService.configure(request);
       });
 
-    return this.rdbService.buildList<T>(href$) as Observable<RemoteData<PaginatedList<T>>>;
+    return this.rdbService.buildList<T>(href$, ...linksToFollow) as Observable<RemoteData<PaginatedList<T>>>;
   }
 
   /**
@@ -167,7 +167,7 @@ export abstract class DataService<T extends CacheableObject> {
     return `${endpoint}/${resourceID}`;
   }
 
-  findById(id: string): Observable<RemoteData<T>> {
+  findById(id: string, ...linksToFollow: Array<FollowLinkConfig<T>>): Observable<RemoteData<T>> {
 
     const hrefObs = this.halService.getEndpoint(this.linkPath).pipe(
       map((endpoint: string) => this.getIDHref(endpoint, encodeURIComponent(id))));
@@ -182,27 +182,27 @@ export abstract class DataService<T extends CacheableObject> {
         this.requestService.configure(request);
       });
 
-    return this.rdbService.buildSingle<T>(hrefObs);
+    return this.rdbService.buildSingle<T>(hrefObs, ...linksToFollow);
   }
 
-  findByHref(href: string, findListOptions: FindListOptions = {}, httpOptions?: HttpOptions): Observable<RemoteData<T>> {
+  findByHref(href: string, ...linksToFollow: Array<FollowLinkConfig<T>>): Observable<RemoteData<T>> {
-    const requestHref = this.buildHrefFromFindOptions(href, findListOptions, []);
+    const requestHref = this.buildHrefFromFindOptions(href, {}, []);
-    const request = new GetRequest(this.requestService.generateRequestId(), requestHref, null, httpOptions);
+    const request = new GetRequest(this.requestService.generateRequestId(), requestHref);
     if (hasValue(this.responseMsToLive)) {
       request.responseMsToLive = this.responseMsToLive;
     }
     this.requestService.configure(request);
-    return this.rdbService.buildSingle<T>(href);
+    return this.rdbService.buildSingle<T>(href, ...linksToFollow);
   }
 
-  findAllByHref(href: string, findListOptions: FindListOptions = {}, httpOptions?: HttpOptions): Observable<RemoteData<PaginatedList<T>>> {
+  findAllByHref(href: string, findListOptions: FindListOptions = {}, ...linksToFollow: Array<FollowLinkConfig<T>>): Observable<RemoteData<PaginatedList<T>>> {
     const requestHref = this.buildHrefFromFindOptions(href, findListOptions, []);
-    const request = new GetRequest(this.requestService.generateRequestId(), requestHref, null, httpOptions);
+    const request = new GetRequest(this.requestService.generateRequestId(), requestHref);
     if (hasValue(this.responseMsToLive)) {
       request.responseMsToLive = this.responseMsToLive;
     }
     this.requestService.configure(request);
-    return this.rdbService.buildList<T>(requestHref);
+    return this.rdbService.buildList<T>(requestHref, ...linksToFollow);
   }
 
   /**
@@ -224,7 +224,7 @@ export abstract class DataService<T extends CacheableObject> {
    * @return {Observable<RemoteData<PaginatedList<T>>}
    *    Return an observable that emits response from the server
    */
-  protected searchBy(searchMethod: string, options: FindListOptions = {}): Observable<RemoteData<PaginatedList<T>>> {
+  protected searchBy(searchMethod: string, options: FindListOptions = {}, ...linksToFollow: Array<FollowLinkConfig<T>>): Observable<RemoteData<PaginatedList<T>>> {
 
     const hrefObs = this.getSearchByHref(searchMethod, options);
 
@@ -241,7 +241,7 @@ export abstract class DataService<T extends CacheableObject> {
       switchMap((href) => this.requestService.getByHref(href)),
       skipWhile((requestEntry) => hasValue(requestEntry) && requestEntry.completed),
       switchMap((href) =>
-        this.rdbService.buildList<T>(hrefObs) as Observable<RemoteData<PaginatedList<T>>>
+        this.rdbService.buildList<T>(hrefObs, ...linksToFollow) as Observable<RemoteData<PaginatedList<T>>>
       )
     );
   }

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

@@ -83,7 +83,7 @@ describe('DsoRedirectDataService', () => {
   describe('findById', () => {
     it('should call HALEndpointService with the path to the pid endpoint', () => {
       setup();
-      scheduler.schedule(() => service.findById(dsoHandle, IdentifierType.HANDLE));
+      scheduler.schedule(() => service.findByIdAndIDType(dsoHandle, IdentifierType.HANDLE));
       scheduler.flush();
 
       expect(halService.getEndpoint).toHaveBeenCalledWith('pid');
@@ -91,7 +91,7 @@ describe('DsoRedirectDataService', () => {
 
     it('should call HALEndpointService with the path to the dso endpoint', () => {
       setup();
-      scheduler.schedule(() => service.findById(dsoUUID, IdentifierType.UUID));
+      scheduler.schedule(() => service.findByIdAndIDType(dsoUUID, IdentifierType.UUID));
       scheduler.flush();
 
       expect(halService.getEndpoint).toHaveBeenCalledWith('dso');
@@ -99,7 +99,7 @@ describe('DsoRedirectDataService', () => {
 
     it('should call HALEndpointService with the path to the dso endpoint when identifier type not specified', () => {
       setup();
-      scheduler.schedule(() => service.findById(dsoUUID));
+      scheduler.schedule(() => service.findByIdAndIDType(dsoUUID));
       scheduler.flush();
 
       expect(halService.getEndpoint).toHaveBeenCalledWith('dso');
@@ -107,7 +107,7 @@ describe('DsoRedirectDataService', () => {
 
     it('should configure the proper FindByIDRequest for uuid', () => {
       setup();
-      scheduler.schedule(() => service.findById(dsoUUID, IdentifierType.UUID));
+      scheduler.schedule(() => service.findByIdAndIDType(dsoUUID, IdentifierType.UUID));
       scheduler.flush();
 
       expect(requestService.configure).toHaveBeenCalledWith(new FindByIDRequest(requestUUID, requestUUIDURL, dsoUUID));
@@ -115,7 +115,7 @@ describe('DsoRedirectDataService', () => {
 
     it('should configure the proper FindByIDRequest for handle', () => {
       setup();
-      scheduler.schedule(() => service.findById(dsoHandle, IdentifierType.HANDLE));
+      scheduler.schedule(() => service.findByIdAndIDType(dsoHandle, IdentifierType.HANDLE));
       scheduler.flush();
 
       expect(requestService.configure).toHaveBeenCalledWith(new FindByIDRequest(requestUUID, requestHandleURL, dsoHandle));
@@ -124,7 +124,7 @@ describe('DsoRedirectDataService', () => {
     it('should navigate to item route', () => {
       remoteData.payload.type = 'item';
       setup();
-      const redir = service.findById(dsoHandle, IdentifierType.HANDLE);
+      const redir = service.findByIdAndIDType(dsoHandle, IdentifierType.HANDLE);
       // The framework would normally subscribe but do it here so we can test navigation.
       redir.subscribe();
       scheduler.schedule(() => redir);
@@ -135,7 +135,7 @@ describe('DsoRedirectDataService', () => {
     it('should navigate to collections route', () => {
       remoteData.payload.type = 'collection';
       setup();
-      const redir = service.findById(dsoHandle, IdentifierType.HANDLE);
+      const redir = service.findByIdAndIDType(dsoHandle, IdentifierType.HANDLE);
       redir.subscribe();
       scheduler.schedule(() => redir);
       scheduler.flush();
@@ -145,7 +145,7 @@ describe('DsoRedirectDataService', () => {
     it('should navigate to communities route', () => {
       remoteData.payload.type = 'community';
       setup();
-      const redir = service.findById(dsoHandle, IdentifierType.HANDLE);
+      const redir = service.findByIdAndIDType(dsoHandle, IdentifierType.HANDLE);
       redir.subscribe();
       scheduler.schedule(() => redir);
       scheduler.flush();

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

@@ -58,9 +58,9 @@ export class DsoRedirectDataService extends DataService<any> {
       .replace(/\{\?uuid\}/, `?uuid=${resourceID}`);
   }
 
-  findById(id: string, identifierType = IdentifierType.UUID): Observable<RemoteData<FindByIDRequest>> {
+  findByIdAndIDType(id: string, identifierType = IdentifierType.UUID): Observable<RemoteData<FindByIDRequest>> {
     this.setLinkPath(identifierType);
-    return super.findById(id).pipe(
+    return this.findById(id).pipe(
       getFinishedRemoteData(),
       take(1),
       tap((response) => {

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

@@ -1,6 +1,7 @@
 import { Injectable } from '@angular/core';
 import { Store } from '@ngrx/store';
 import { Observable } from 'rxjs';
+import { dataService } from '../cache/builders/build-decorators';
 import { RemoteDataBuildService } from '../cache/builders/remote-data-build.service';
 import { CoreState } from '../core.reducers';
 import { DSpaceObject } from '../shared/dspace-object.model';
@@ -42,6 +43,7 @@ class DataServiceImpl extends DataService<DSpaceObject> {
 }
 
 @Injectable()
+@dataService(DSpaceObject)
 export class DSpaceObjectDataService {
   protected linkPath = 'dso';
   private dataService: DataServiceImpl;

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

@@ -4,6 +4,7 @@ import { Store } from '@ngrx/store';
 import { Observable } from 'rxjs';
 import { hasValue, isNotEmpty, isNotEmptyOperator } from '../../shared/empty.util';
 import { BrowseService } from '../browse/browse.service';
+import { dataService } from '../cache/builders/build-decorators';
 import { RemoteDataBuildService } from '../cache/builders/remote-data-build.service';
 import { CoreState } from '../core.reducers';
 import { Item } from '../shared/item.model';
@@ -40,6 +41,7 @@ import { PaginatedList } from './paginated-list';
 import { ExternalSourceEntry } from '../shared/external-source-entry.model';
 
 @Injectable()
+@dataService(Item)
 export class ItemDataService extends DataService<Item> {
   protected linkPath = 'items';
 

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

@@ -1,6 +1,7 @@
 import { Injectable } from '@angular/core';
 import { Store } from '@ngrx/store';
 import { Observable } from 'rxjs';
+import { dataService } from '../cache/builders/build-decorators';
 import { RemoteDataBuildService } from '../cache/builders/remote-data-build.service';
 import { CoreState } from '../core.reducers';
 
@@ -42,6 +43,7 @@ class DataServiceImpl extends DataService<MetadataSchema> {
  * A service responsible for fetching/sending data from/to the REST API on the metadataschemas endpoint
  */
 @Injectable()
+@dataService(MetadataSchema)
 export class MetadataSchemaDataService {
   private dataService: DataServiceImpl;
 

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

@@ -1,47 +1,36 @@
+import { HttpClient, HttpHeaders } from '@angular/common/http';
 import { Injectable } from '@angular/core';
-import { ReorderableRelationship } from '../../shared/form/builder/ds-dynamic-form-ui/existing-metadata-list-element/existing-metadata-list-element.component';
+import { dataService } from '../cache/builders/build-decorators';
-import { RequestService } from './request.service';
+import { MemoizedSelector, select, Store } from '@ngrx/store';
-import { HALEndpointService } from '../shared/hal-endpoint.service';
+import { combineLatest, combineLatest as observableCombineLatest } from 'rxjs';
-import { RemoteDataBuildService } from '../cache/builders/remote-data-build.service';
-import { hasValue, hasValueOperator, isNotEmpty, isNotEmptyOperator } from '../../shared/empty.util';
 import { distinctUntilChanged, filter, map, mergeMap, startWith, switchMap, take, tap } from 'rxjs/operators';
-import {
+import { compareArraysUsingIds, paginatedRelationsToItems, relationsToItems } from '../../+item-page/simple/item-types/shared/item-relationships-utils';
-  configureRequest,
+import { AppState, keySelector } from '../../app.reducer';
-  getRemoteDataPayload,
+import { hasValue, hasValueOperator, isNotEmpty, isNotEmptyOperator } from '../../shared/empty.util';
-  getResponseFromEntry,
+import { ReorderableRelationship } from '../../shared/form/builder/ds-dynamic-form-ui/existing-metadata-list-element/existing-metadata-list-element.component';
-  getSucceededRemoteData
+import { RemoveNameVariantAction, SetNameVariantAction } from '../../shared/form/builder/ds-dynamic-form-ui/relation-lookup-modal/name-variant.actions';
-} from '../shared/operators';
+import { NameVariantListState } from '../../shared/form/builder/ds-dynamic-form-ui/relation-lookup-modal/name-variant.reducer';
+import { NotificationsService } from '../../shared/notifications/notifications.service';
+import { NormalizedObjectBuildService } from '../cache/builders/normalized-object-build.service';
+import { RemoteDataBuildService } from '../cache/builders/remote-data-build.service';
+import { configureRequest, getRemoteDataPayload, getResponseFromEntry, getSucceededRemoteData } from '../shared/operators';
+import { SearchParam } from '../cache/models/search-param.model';
+import { ObjectCacheService } from '../cache/object-cache.service';
 import { DeleteRequest, FindListOptions, PostRequest, RestRequest } from './request.models';
-import { Observable } from 'rxjs/internal/Observable';
 import { RestResponse } from '../cache/response.models';
-import { Item } from '../shared/item.model';
+import { CoreState } from '../core.reducers';
-import { Relationship } from '../shared/item-relationships/relationship.model';
+import { HttpOptions } from '../dspace-rest-v2/dspace-rest-v2.service';
+import { HALEndpointService } from '../shared/hal-endpoint.service';
 import { RelationshipType } from '../shared/item-relationships/relationship-type.model';
 import { RemoteData, RemoteDataState } from './remote-data';
-import { combineLatest, combineLatest as observableCombineLatest } from 'rxjs';
 import { PaginatedList } from './paginated-list';
 import { ItemDataService } from './item-data.service';
-import {
+import { Relationship } from '../shared/item-relationships/relationship.model';
-  compareArraysUsingIds,
+import { Item } from '../shared/item.model';
-  paginatedRelationsToItems,
-  relationsToItems
-} from '../../+item-page/simple/item-types/shared/item-relationships-utils';
-import { ObjectCacheService } from '../cache/object-cache.service';
 import { DataService } from './data.service';
-import { NormalizedObjectBuildService } from '../cache/builders/normalized-object-build.service';
-import { MemoizedSelector, select, Store } from '@ngrx/store';
-import { CoreState } from '../core.reducers';
-import { NotificationsService } from '../../shared/notifications/notifications.service';
-import { HttpClient, HttpHeaders } from '@angular/common/http';
 import { DefaultChangeAnalyzer } from './default-change-analyzer.service';
-import { SearchParam } from '../cache/models/search-param.model';
+import { RequestService } from './request.service';
-import { HttpOptions } from '../dspace-rest-v2/dspace-rest-v2.service';
+import { Observable } from 'rxjs/internal/Observable';
-import { AppState, keySelector } from '../../app.reducer';
-import { NameVariantListState } from '../../shared/form/builder/ds-dynamic-form-ui/relation-lookup-modal/name-variant.reducer';
-import {
-  RemoveNameVariantAction,
-  SetNameVariantAction
-} from '../../shared/form/builder/ds-dynamic-form-ui/relation-lookup-modal/name-variant.actions';
 
 const relationshipListsStateSelector = (state: AppState) => state.relationshipLists;
 
@@ -57,9 +46,9 @@ const relationshipStateSelector = (listID: string, itemID: string): MemoizedSele
  * The service handling all relationship requests
  */
 @Injectable()
+@dataService(Relationship)
 export class RelationshipService extends DataService<Relationship> {
   protected linkPath = 'relationships';
-  protected forceBypassCache = false;
 
   constructor(protected itemService: ItemDataService,
               protected requestService: RequestService,

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

@@ -7,6 +7,7 @@ import { Observable } from 'rxjs';
 import { DataService } from '../data/data.service';
 import { RequestService } from '../data/request.service';
 import { FindListOptions } from '../data/request.models';
+import { Collection } from '../shared/collection.model';
 import { HALEndpointService } from '../shared/hal-endpoint.service';
 import { ResourcePolicy } from '../shared/resource-policy.model';
 import { RemoteData } from '../data/remote-data';
@@ -17,7 +18,7 @@ import { NotificationsService } from '../../shared/notifications/notifications.s
 import { NormalizedObjectBuildService } from '../cache/builders/normalized-object-build.service';
 import { ChangeAnalyzer } from './change-analyzer';
 import { DefaultChangeAnalyzer } from '../data/default-change-analyzer.service';
-import { HttpOptions } from '../dspace-rest-v2/dspace-rest-v2.service';
+import { PaginatedList } from './paginated-list';
 
 /* tslint:disable:max-classes-per-file */
 class DataServiceImpl extends DataService<ResourcePolicy> {
@@ -60,7 +61,11 @@ export class ResourcePolicyService {
     this.dataService = new DataServiceImpl(requestService, rdbService, dataBuildService, null, objectCache, halService, notificationsService, http, comparator);
   }
 
-  findByHref(href: string, options?: HttpOptions): Observable<RemoteData<ResourcePolicy>> {
+  findByHref(href: string): Observable<RemoteData<ResourcePolicy>> {
-    return this.dataService.findByHref(href, {}, options);
+    return this.dataService.findByHref(href);
+  }
+
+  getDefaultAccessConditionsFor(collection: Collection, findListOptions?: FindListOptions): Observable<RemoteData<PaginatedList<ResourcePolicy>>> {
+    return this.dataService.findAllByHref(collection._links.defaultAccessConditions.href, findListOptions);
   }
 }

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

@@ -1,3 +1,4 @@
+import { dataService } from '../cache/builders/build-decorators';
 import { DataService } from './data.service';
 import { Site } from '../shared/site.model';
 import { RequestService } from './request.service';
@@ -22,6 +23,7 @@ import { getSucceededRemoteData } from '../shared/operators';
  * Service responsible for handling requests related to the Site object
  */
 @Injectable()
+@dataService(Site)
 export class SiteDataService extends DataService<Site> {​
   protected linkPath = 'sites';
   protected forceBypassCache = false;

src/app/core/dspace-rest-v2/dspace-rest-v2.serializer.ts

@@ -77,14 +77,16 @@ export class DSpaceRESTv2Serializer<T> implements Serializer<T> {
   }
 
   private normalizeLinks(links: any): any {
-    const normalizedLinks = links;
+    const normalizedLinks = {};
-    for (const link in normalizedLinks) {
+    for (const link in links) {
-      if (Array.isArray(normalizedLinks[link])) {
+      if (links.hasOwnProperty(link)) {
-        normalizedLinks[link] = normalizedLinks[link].map((linkedResource) => {
+        if (Array.isArray(links[link])) {
-          return linkedResource.href;
+          normalizedLinks[link] = links[link].map((linkedResource) => {
-        });
+            return linkedResource.href;
-      } else {
+          });
-        normalizedLinks[link] = normalizedLinks[link].href;
+        } else {
+          normalizedLinks[link] = links[link].href;
+        }
       }
     }
     return normalizedLinks;

src/app/core/integration/models/integration.model.ts

@@ -1,5 +1,6 @@
 import { autoserialize } from 'cerialize';
 import { CacheableObject } from '../../cache/object-cache.reducer';
+import { HALLink } from '../../shared/hal-link.model';
 
 export abstract class IntegrationModel implements CacheableObject {
 
@@ -14,7 +15,8 @@ export abstract class IntegrationModel implements CacheableObject {
 
   @autoserialize
   public _links: {
-    [name: string]: string
+    self: HALLink,
+    [name: string]: HALLink
   }
 
 }

src/app/core/metadata/metadata-field.model.ts

@@ -1,5 +1,8 @@
 import { ListableObject } from '../../shared/object-collection/shared/listable-object.model';
 import { isNotEmpty } from '../../shared/empty.util';
+import { link } from '../cache/builders/build-decorators';
+import { HALLink } from '../shared/hal-link.model';
+import { HALResource } from '../shared/hal-resource.model';
 import { MetadataSchema } from './metadata-schema.model';
 import { ResourceType } from '../shared/resource-type';
 import { GenericConstructor } from '../shared/generic-constructor';
@@ -7,7 +10,7 @@ import { GenericConstructor } from '../shared/generic-constructor';
 /**
  * Class the represents a metadata field
  */
-export class MetadataField extends ListableObject {
+export class MetadataField extends ListableObject implements HALResource {
   static type = new ResourceType('metadatafield');
 
   /**
@@ -38,7 +41,14 @@ export class MetadataField extends ListableObject {
   /**
    * The metadata schema object of this metadata field
    */
-  schema: MetadataSchema;
+  @link(MetadataSchema)
+  // TODO the responseparsingservice assumes schemas are always embedded. This should be remotedata instead.
+  schema?: MetadataSchema;
+
+  _links: {
+    self: HALLink,
+    schema: HALLink
+  };
 
   /**
    * Method to print this metadata field as a string

src/app/core/metadata/metadata-schema.model.ts

@@ -1,11 +1,13 @@
 import { ListableObject } from '../../shared/object-collection/shared/listable-object.model';
+import { HALLink } from '../shared/hal-link.model';
+import { HALResource } from '../shared/hal-resource.model';
 import { ResourceType } from '../shared/resource-type';
 import { GenericConstructor } from '../shared/generic-constructor';
 
 /**
  * Class that represents a metadata schema
  */
-export class MetadataSchema extends ListableObject {
+export class MetadataSchema extends ListableObject implements HALResource {
   static type = new ResourceType('metadataschema');
 
   /**
@@ -28,6 +30,10 @@ export class MetadataSchema extends ListableObject {
    */
   namespace: string;
 
+  _links: {
+    self: HALLink,
+  };
+
   /**
    * Method that returns as which type of object this object should be rendered
    */

src/app/core/shared/bitstream-format.model.ts

@@ -1,4 +1,5 @@
 import { CacheableObject, TypedObject } from '../cache/object-cache.reducer';
+import { HALLink } from './hal-link.model';
 import { ResourceType } from './resource-type';
 import { BitstreamFormatSupportLevel } from './bitstream-format-support-level';
 
@@ -56,4 +57,7 @@ export class BitstreamFormat implements CacheableObject {
    */
   id: string;
 
+  _links: {
+    self: HALLink;
+  }
 }

src/app/core/shared/bitstream.model.ts

@@ -1,11 +1,14 @@
 import { Observable } from 'rxjs';
+import { link } from '../cache/builders/build-decorators';
 import { RemoteData } from '../data/remote-data';
 import { BitstreamFormat } from './bitstream-format.model';
+import { Bundle } from './bundle.model';
 import { DSpaceObject } from './dspace-object.model';
-import { HALLink } from './HALLink.model';
+import { HALResource } from './hal-resource.model';
+import { HALLink } from './hal-link.model';
 import { ResourceType } from './resource-type';
 
-export class Bitstream extends DSpaceObject {
+export class Bitstream extends DSpaceObject implements HALResource {
   static type = new ResourceType('bitstream');
 
   /**
@@ -31,17 +34,19 @@ export class Bitstream extends DSpaceObject {
   /**
    * The Bitstream Format for this Bitstream
    */
+  @link(BitstreamFormat)
   format?: Observable<RemoteData<BitstreamFormat>>;
 
-  /**
-   * The URL to retrieve this Bitstream's file
-   */
-  content: string;
-
   _links: {
+    // @link(Bitstream)
     self: HALLink;
+
+    // @link(Bundle)
     bundle: HALLink;
-    content: HALLink;
+
+    // @link(BitstreamFormat)
     format: HALLink;
+
+    content: HALLink;
   }
 }

src/app/core/shared/bundle.model.ts

@@ -1,5 +1,5 @@
 import { DSpaceObject } from './dspace-object.model';
-import { HALLink } from './HALLink.model';
+import { HALLink } from './hal-link.model';
 import { ResourceType } from './resource-type';
 
 export class Bundle extends DSpaceObject {

src/app/core/shared/collection.model.ts

@@ -1,6 +1,7 @@
+import { link } from '../cache/builders/build-decorators';
 import { DSpaceObject } from './dspace-object.model';
 import { Bitstream } from './bitstream.model';
-import { HALLink } from './HALLink.model';
+import { HALLink } from './hal-link.model';
 import { Item } from './item.model';
 import { RemoteData } from '../data/remote-data';
 import { Observable } from 'rxjs';
@@ -60,29 +61,19 @@ export class Collection extends DSpaceObject {
   /**
    * The deposit license of this Collection
    */
-  license: Observable<RemoteData<License>>;
+//  license?: Observable<RemoteData<License>>;
 
   /**
    * The Bitstream that represents the logo of this Collection
    */
-  logo: Observable<RemoteData<Bitstream>>;
+  @link(Bitstream)
+  logo?: Observable<RemoteData<Bitstream>>;
 
   /**
    * The default access conditions of this Collection
    */
-  defaultAccessConditions: Observable<RemoteData<PaginatedList<ResourcePolicy>>>;
+  @link(ResourcePolicy, true)
-
+  defaultAccessConditions?: Observable<RemoteData<PaginatedList<ResourcePolicy>>>;
-  /**
-   * An array of Collections that are direct parents of this Collection
-   */
-  parents: Observable<RemoteData<Collection[]>>;
-
-  /**
-   * The Collection that owns this Collection
-   */
-  owner: Observable<RemoteData<Collection>>;
-
-  items: Observable<RemoteData<Item[]>>;
 
   _links: {
     license: HALLink;

src/app/core/shared/community.model.ts

@@ -1,9 +1,11 @@
+import { link } from '../cache/builders/build-decorators';
 import { DSpaceObject } from './dspace-object.model';
 import { Bitstream } from './bitstream.model';
 import { Collection } from './collection.model';
 import { RemoteData } from '../data/remote-data';
 import { Observable } from 'rxjs';
 import { PaginatedList } from '../data/paginated-list';
+import { HALLink } from './hal-link.model';
 import { ResourceType } from './resource-type';
 
 export class Community extends DSpaceObject {
@@ -49,20 +51,19 @@ export class Community extends DSpaceObject {
   /**
    * The Bitstream that represents the logo of this Community
    */
-  logo: Observable<RemoteData<Bitstream>>;
+  @link(Bitstream)
+  logo?: Observable<RemoteData<Bitstream>>;
 
-  /**
+  @link(Collection, true)
-   * An array of Communities that are direct parents of this Community
+  collections?: Observable<RemoteData<PaginatedList<Collection>>>;
-   */
-  parents: Observable<RemoteData<DSpaceObject[]>>;
 
-  /**
+  @link(Community, true)
-   * The Community that owns this Community
+  subcommunities?: Observable<RemoteData<PaginatedList<Community>>>;
-   */
-  owner: Observable<RemoteData<Community>>;
-
-  collections: Observable<RemoteData<PaginatedList<Collection>>>;
-
-  subcommunities: Observable<RemoteData<PaginatedList<Community>>>;
 
+  _links: {
+    collections: HALLink;
+    logo: HALLink;
+    subcommunities: HALLink;
+    self: HALLink;
+  }
 }

src/app/core/shared/dspace-object.model.ts

@@ -1,5 +1,5 @@
-import { Observable } from 'rxjs';
+import { GenericConstructor } from './generic-constructor';
-
+import { HALLink } from './hal-link.model';
 import {
   MetadataMap,
   MetadataValue,
@@ -9,11 +9,9 @@ import {
 import { Metadata } from './metadata.utils';
 import { hasNoValue, isUndefined } from '../../shared/empty.util';
 import { CacheableObject } from '../cache/object-cache.reducer';
-import { RemoteData } from '../data/remote-data';
 import { ListableObject } from '../../shared/object-collection/shared/listable-object.model';
 import { excludeFromEquals } from '../utilities/equals.decorators';
 import { ResourceType } from './resource-type';
-import { GenericConstructor } from './generic-constructor';
 
 /**
  * An abstract model class for a DSpaceObject.
@@ -67,6 +65,10 @@ export class DSpaceObject extends ListableObject implements CacheableObject {
   @excludeFromEquals
   metadata: MetadataMap;
 
+  _links: {
+    self: HALLink,
+  };
+
   /**
    * Retrieve the current metadata as a list of MetadatumViewModels
    */
@@ -74,18 +76,6 @@ export class DSpaceObject extends ListableObject implements CacheableObject {
     return Metadata.toViewModelList(this.metadata);
   }
 
-  /**
-   * An array of DSpaceObjects that are direct parents of this DSpaceObject
-   */
-  @excludeFromEquals
-  parents: Observable<RemoteData<DSpaceObject[]>>;
-
-  /**
-   * The DSpaceObject that owns this DSpaceObject
-   */
-  @excludeFromEquals
-  owner: Observable<RemoteData<DSpaceObject>>;
-
   /**
    * Gets all matching metadata in this DSpaceObject.
    *

src/app/core/shared/hal-resource.model.ts

@@ -0,0 +1,8 @@
+import { HALLink } from './hal-link.model';
+
+export class HALResource {
+  _links: {
+    self: HALLink
+    [k: string]: HALLink;
+  };
+}

src/app/core/shared/item-relationships/item-type.model.ts

@@ -1,4 +1,5 @@
 import { CacheableObject } from '../../cache/object-cache.reducer';
+import { HALLink } from '../hal-link.model';
 import { ResourceType } from '../resource-type';
 
 /**
@@ -23,4 +24,8 @@ export class ItemType implements CacheableObject {
    * The universally unique identifier of this ItemType
    */
   uuid: string;
+
+  _links: {
+    self: HALLink,
+  };
 }

src/app/core/shared/item-relationships/relationship-type.model.ts

@@ -1,6 +1,8 @@
 import { Observable } from 'rxjs';
+import { link } from '../../cache/builders/build-decorators';
 import { CacheableObject } from '../../cache/object-cache.reducer';
 import { RemoteData } from '../../data/remote-data';
+import { HALLink } from '../hal-link.model';
 import { ResourceType } from '../resource-type';
 import { ItemType } from './item-type.model';
 
@@ -63,10 +65,18 @@ export class RelationshipType implements CacheableObject {
   /**
    * The type of Item found to the left of this RelationshipType
    */
-  leftType: Observable<RemoteData<ItemType>>;
+  @link(ItemType)
+  leftType?: Observable<RemoteData<ItemType>>;
 
   /**
    * The type of Item found to the right of this RelationshipType
    */
-  rightType: Observable<RemoteData<ItemType>>;
+  @link(ItemType)
+  rightType?: Observable<RemoteData<ItemType>>;
+
+  _links: {
+    self: HALLink,
+    leftType: HALLink,
+    rightType: HALLink,
+  }
 }

src/app/core/shared/item-relationships/relationship.model.ts

@@ -1,6 +1,8 @@
 import { Observable } from 'rxjs';
+import { link } from '../../cache/builders/build-decorators';
 import { CacheableObject } from '../../cache/object-cache.reducer';
 import { RemoteData } from '../../data/remote-data';
+import { HALLink } from '../hal-link.model';
 import { ResourceType } from '../resource-type';
 import { RelationshipType } from './relationship-type.model';
 import { Item } from '../item.model';
@@ -29,12 +31,14 @@ export class Relationship implements CacheableObject {
   /**
    * The item to the left of this relationship
    */
-  leftItem: Observable<RemoteData<Item>>;
+  @link(Item)
+  leftItem?: Observable<RemoteData<Item>>;
 
   /**
    * The item to the right of this relationship
    */
-  rightItem: Observable<RemoteData<Item>>;
+  @link(Item)
+  rightItem?: Observable<RemoteData<Item>>;
 
   /**
    * The place of the Item to the left side of this Relationship
@@ -59,5 +63,14 @@ export class Relationship implements CacheableObject {
   /**
    * The type of Relationship
    */
-  relationshipType: Observable<RemoteData<RelationshipType>>;
+  @link(RelationshipType)
+  relationshipType?: Observable<RemoteData<RelationshipType>>;
+
+  _links: {
+    self: HALLink,
+    leftItem: HALLink,
+    rightItem: HALLink,
+    relationshipType: HALLink,
+  }
+
 }

src/app/core/shared/item.model.ts

@@ -1,10 +1,16 @@
+import { Observable } from 'rxjs/internal/Observable';
 import { isEmpty } from '../../shared/empty.util';
 import { DEFAULT_ENTITY_TYPE } from '../../shared/metadata-representation/metadata-representation.decorator';
 import { ListableObject } from '../../shared/object-collection/shared/listable-object.model';
+import { link } from '../cache/builders/build-decorators';
+import { PaginatedList } from '../data/paginated-list';
+import { RemoteData } from '../data/remote-data';
+import { Bundle } from './bundle.model';
 
 import { DSpaceObject } from './dspace-object.model';
 import { GenericConstructor } from './generic-constructor';
-import { HALLink } from './HALLink.model';
+import { HALLink } from './hal-link.model';
+import { Relationship } from './item-relationships/relationship.model';
 import { ResourceType } from './resource-type';
 
 /**
@@ -38,12 +44,19 @@ export class Item extends DSpaceObject {
    */
   isWithdrawn: boolean;
 
+  @link(Bundle, true)
+  bundles: Observable<RemoteData<PaginatedList<Bundle>>>;
+
+  @link(Relationship, true)
+  relationships: Observable<RemoteData<PaginatedList<Relationship>>>;
+
   _links: {
-    self: HALLink;
+    mappedCollections: HALLink;
-    parents: HALLink;
-    owningCollection: HALLink;
-    bundles: HALLink;
     relationships: HALLink;
+    bundles: HALLink;
+    owningCollection: HALLink;
+    templateItemOf: HALLink;
+    self: HALLink;
   };
 
   /**

src/app/core/shared/resource-policy.model.ts

@@ -1,4 +1,5 @@
 import { CacheableObject } from '../cache/object-cache.reducer';
+import { HALLink } from './hal-link.model';
 import { ResourceType } from './resource-type';
 import { ActionType } from '../cache/models/action-type.model';
 
@@ -33,4 +34,7 @@ export class ResourcePolicy implements CacheableObject {
    */
   uuid: string;
 
+  _links: {
+    self: HALLink,
+  }
 }

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

@@ -2,6 +2,7 @@ import { combineLatest as observableCombineLatest, Observable, of as observableO
 import { Injectable, OnDestroy } from '@angular/core';
 import { NavigationExtras, Router } from '@angular/router';
 import { first, map, switchMap, tap } from 'rxjs/operators';
+import { followLink } from '../../../shared/utils/follow-link-config.model';
 import { FacetConfigSuccessResponse, FacetValueSuccessResponse, SearchSuccessResponse } from '../../cache/response.models';
 import { PaginatedList } from '../../data/paginated-list';
 import { ResponseParsingService } from '../../data/parsing.service';
@@ -340,6 +341,8 @@ export class SearchService implements OnDestroy {
       switchMap((dsoRD: RemoteData<DSpaceObject>) => {
           if ((dsoRD.payload as any).type === Community.type.value) {
             const community: Community = dsoRD.payload as Community;
+            this.rdb.resolveLink(community, followLink('subcommunities'));
+            this.rdb.resolveLink(community, followLink('collections'));
             return observableCombineLatest(community.subcommunities, community.collections).pipe(
               map(([subCommunities, collections]) => {
                 /*if this is a community, we also need to show the direct children*/

src/app/core/submission/models/submission-object.model.ts

@@ -1,10 +1,12 @@
 import { Observable } from 'rxjs';
+import { link } from '../../cache/builders/build-decorators';
 
 import { CacheableObject } from '../../cache/object-cache.reducer';
 import { DSpaceObject } from '../../shared/dspace-object.model';
 import { EPerson } from '../../eperson/models/eperson.model';
 import { RemoteData } from '../../data/remote-data';
 import { Collection } from '../../shared/collection.model';
+import { HALLink } from '../../shared/hal-link.model';
 import { Item } from '../../shared/item.model';
 import { SubmissionDefinitionsModel } from '../../config/models/config-submission-definitions.model';
 import { WorkspaceitemSectionsObject } from './workspaceitem-sections.model';
@@ -37,12 +39,14 @@ export abstract class SubmissionObject extends DSpaceObject implements Cacheable
   /**
    * The collection this submission applies to
    */
-  collection: Observable<RemoteData<Collection>> | Collection;
+  @link(Collection)
+  collection?: Observable<RemoteData<Collection>> | Collection;
 
   /**
    * The submission item
    */
-  item: Observable<RemoteData<Item>> | Item;
+  @link(Item)
+  item?: Observable<RemoteData<Item>> | Item;
 
   /**
    * The workspaceitem/workflowitem last sections data
@@ -52,15 +56,26 @@ export abstract class SubmissionObject extends DSpaceObject implements Cacheable
   /**
    * The configuration object that define this submission
    */
-  submissionDefinition: Observable<RemoteData<SubmissionDefinitionsModel>> | SubmissionDefinitionsModel;
+  @link(SubmissionDefinitionsModel)
+  submissionDefinition?: Observable<RemoteData<SubmissionDefinitionsModel>> | SubmissionDefinitionsModel;
 
   /**
    * The workspaceitem submitter
    */
-  submitter: Observable<RemoteData<EPerson>> | EPerson;
+  @link(EPerson)
+  submitter?: Observable<RemoteData<EPerson>> | EPerson;
 
   /**
    * The workspaceitem/workflowitem last sections errors
    */
   errors: SubmissionObjectError[];
+
+  _links: {
+    self: HALLink,
+    collection: HALLink,
+    item: HALLink,
+    submissionDefinition: HALLink,
+    submitter: HALLink,
+  }
+
 }

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

@@ -45,7 +45,7 @@ describe('SubmissionObjectDataService', () => {
         service = new SubmissionObjectDataService(workspaceitemDataService, workflowItemDataService, submissionService);
       });
 
-      it('should forward the result of WorkspaceitemDataService.findById()', () => {
+      it('should forward the result of WorkspaceitemDataService.findByIdAndIDType()', () => {
         const result = service.findById(submissionId);
         expect(workspaceitemDataService.findById).toHaveBeenCalledWith(submissionId);
         expect(result).toBe(wsiResult);
@@ -60,7 +60,7 @@ describe('SubmissionObjectDataService', () => {
         service = new SubmissionObjectDataService(workspaceitemDataService, workflowItemDataService, submissionService);
       });
 
-      it('should forward the result of WorkflowItemDataService.findById()', () => {
+      it('should forward the result of WorkflowItemDataService.findByIdAndIDType()', () => {
         const result = service.findById(submissionId);
         expect(workflowItemDataService.findById).toHaveBeenCalledWith(submissionId);
         expect(result).toBe(wfiResult);

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

@@ -2,6 +2,7 @@ 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 { CoreState } from '../core.reducers';
 import { DataService } from '../data/data.service';
@@ -18,6 +19,7 @@ import { DSOChangeAnalyzer } from '../data/dso-change-analyzer.service';
  * A service that provides methods to make REST requests with workflowitems endpoint.
  */
 @Injectable()
+@dataService(WorkflowItem)
 export class WorkflowItemDataService extends DataService<WorkflowItem> {
   protected linkPath = 'workflowitems';
   protected responseMsToLive = 10 * 1000;

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

@@ -2,6 +2,7 @@ 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 { CoreState } from '../core.reducers';
 import { DataService } from '../data/data.service';
@@ -18,6 +19,7 @@ import { WorkspaceItem } from './models/workspaceitem.model';
  * A service that provides methods to make REST requests with workspaceitems endpoint.
  */
 @Injectable()
+@dataService(WorkspaceItem)
 export class WorkspaceitemDataService extends DataService<WorkspaceItem> {
   protected linkPath = 'workspaceitems';
   protected responseMsToLive = 10 * 1000;

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

@@ -3,6 +3,7 @@ import { HttpClient } from '@angular/common/http';
 
 import { Store } from '@ngrx/store';
 import { Observable } from 'rxjs';
+import { dataService } from '../cache/builders/build-decorators';
 
 import { RemoteDataBuildService } from '../cache/builders/remote-data-build.service';
 import { CoreState } from '../core.reducers';
@@ -20,6 +21,7 @@ import { ProcessTaskResponse } from './models/process-task-response';
  * The service handling all REST requests for ClaimedTask
  */
 @Injectable()
+@dataService(ClaimedTask)
 export class ClaimedTaskDataService extends TasksService<ClaimedTask> {
 
   protected responseMsToLive = 10 * 1000;

src/app/core/tasks/models/task-object.model.ts

@@ -1,8 +1,10 @@
 import { Observable } from 'rxjs';
+import { link } from '../../cache/builders/build-decorators';
 
 import { CacheableObject } from '../../cache/object-cache.reducer';
 import { DSpaceObject } from '../../shared/dspace-object.model';
 import { RemoteData } from '../../data/remote-data';
+import { HALLink } from '../../shared/hal-link.model';
 import { WorkflowItem } from '../../submission/models/workflowitem.model';
 import { ResourceType } from '../../shared/resource-type';
 import { EPerson } from '../../eperson/models/eperson.model';
@@ -32,15 +34,26 @@ export class TaskObject extends DSpaceObject implements CacheableObject {
   /**
    * The group of this task
    */
-  eperson: Observable<RemoteData<EPerson>>;
+  @link(EPerson)
+  eperson?: Observable<RemoteData<EPerson>>;
 
   /**
    * The group of this task
    */
-  group: Observable<RemoteData<Group>>;
+  @link(Group)
+  group?: Observable<RemoteData<Group>>;
 
   /**
    * The workflowitem object whom this task is related
    */
-  workflowitem: Observable<RemoteData<WorkflowItem>> | WorkflowItem;
+  @link(WorkflowItem)
+  workflowitem?: Observable<RemoteData<WorkflowItem>> | WorkflowItem;
+
+  _links: {
+    self: HALLink,
+    eperson: HALLink,
+    group: HALLink,
+    workflowitem: HALLink,
+  }
+
 }

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

@@ -3,6 +3,7 @@ import { HttpClient } from '@angular/common/http';
 
 import { Observable } from 'rxjs';
 import { Store } from '@ngrx/store';
+import { dataService } from '../cache/builders/build-decorators';
 
 import { RemoteDataBuildService } from '../cache/builders/remote-data-build.service';
 import { CoreState } from '../core.reducers';
@@ -20,6 +21,7 @@ import { ProcessTaskResponse } from './models/process-task-response';
  * The service handling all REST requests for PoolTask
  */
 @Injectable()
+@dataService(PoolTask)
 export class PoolTaskDataService extends TasksService<PoolTask> {
 
   /**

src/app/entity-groups/research-entities/submission/item-list-elements/org-unit/org-unit-search-result-list-submission-element.component.html

@@ -1,6 +1,6 @@
 <div class="d-flex">
     <div class="person-thumbnail pr-2">
-        <ds-thumbnail [thumbnail]="dso.getThumbnail() | async" [defaultImage]="'assets/images/orgunit-placeholder.svg'"></ds-thumbnail>
+        <ds-thumbnail [thumbnail]="getThumbnail() | async" [defaultImage]="'assets/images/orgunit-placeholder.svg'"></ds-thumbnail>
     </div>
     <div class="flex-grow-1">
         <ds-org-unit-input-suggestions [suggestions]="allSuggestions" [(ngModel)]="selectedName" (clickSuggestion)="select($event)"

src/app/entity-groups/research-entities/submission/item-list-elements/org-unit/org-unit-search-result-list-submission-element.component.ts

@@ -1,4 +1,8 @@
 import { Component, OnInit } from '@angular/core';
+import { Observable } from 'rxjs/internal/Observable';
+import { BitstreamDataService } from '../../../../../core/data/bitstream-data.service';
+import { Bitstream } from '../../../../../core/shared/bitstream.model';
+import { getFirstSucceededRemoteDataPayload } from '../../../../../core/shared/operators';
 import { SearchResultListElementComponent } from '../../../../../shared/object-list/search-result-list-element/search-result-list-element.component';
 import { ItemSearchResult } from '../../../../../shared/object-collection/shared/item-search-result.model';
 import { listableObjectComponent } from '../../../../../shared/object-collection/shared/listable-object/listable-object.decorator';
@@ -37,6 +41,7 @@ export class OrgUnitSearchResultListSubmissionElementComponent extends SearchRes
               private translateService: TranslateService,
               private modalService: NgbModal,
               private itemDataService: ItemDataService,
+              private bitstreamDataService: BitstreamDataService,
               private selectableListService: SelectableListService) {
     super(truncatableService);
   }
@@ -95,4 +100,11 @@ export class OrgUnitSearchResultListSubmissionElementComponent extends SearchRes
     modalComp.value = value;
     return modalRef.result;
   }
+
+  // TODO refactor to return RemoteData, and thumbnail template to deal with loading
+  getThumbnail(): Observable<Bitstream> {
+    return this.bitstreamDataService.getThumbnailFor(this.dso).pipe(
+      getFirstSucceededRemoteDataPayload()
+    );
+  }
 }

src/app/entity-groups/research-entities/submission/item-list-elements/person/person-search-result-list-submission-element.component.html

@@ -1,6 +1,6 @@
 <div class="d-flex">
     <div class="person-thumbnail pr-2">
-        <ds-thumbnail [thumbnail]="dso.getThumbnail() | async" [defaultImage]="'assets/images/person-placeholder.svg'"></ds-thumbnail>
+        <ds-thumbnail [thumbnail]="getThumbnail() | async" [defaultImage]="'assets/images/person-placeholder.svg'"></ds-thumbnail>
     </div>
     <div class="flex-grow-1">
         <ds-person-input-suggestions [suggestions]="allSuggestions" [(ngModel)]="selectedName" (clickSuggestion)="select($event)" (submitSuggestion)="selectCustom($event)"></ds-person-input-suggestions>

src/app/entity-groups/research-entities/submission/item-list-elements/person/person-search-result-list-submission-element.component.ts

@@ -1,4 +1,8 @@
 import { Component, OnInit } from '@angular/core';
+import { Observable } from 'rxjs/internal/Observable';
+import { BitstreamDataService } from '../../../../../core/data/bitstream-data.service';
+import { Bitstream } from '../../../../../core/shared/bitstream.model';
+import { getFirstSucceededRemoteDataPayload } from '../../../../../core/shared/operators';
 import { SearchResultListElementComponent } from '../../../../../shared/object-list/search-result-list-element/search-result-list-element.component';
 import { ItemSearchResult } from '../../../../../shared/object-collection/shared/item-search-result.model';
 import { listableObjectComponent } from '../../../../../shared/object-collection/shared/listable-object/listable-object.decorator';
@@ -37,6 +41,7 @@ export class PersonSearchResultListSubmissionElementComponent extends SearchResu
               private translateService: TranslateService,
               private modalService: NgbModal,
               private itemDataService: ItemDataService,
+              private bitstreamDataService: BitstreamDataService,
               private selectableListService: SelectableListService) {
     super(truncatableService);
   }
@@ -95,4 +100,11 @@ export class PersonSearchResultListSubmissionElementComponent extends SearchResu
     modalComp.value = value;
     return modalRef.result;
   }
+
+  // TODO refactor to return RemoteData, and thumbnail template to deal with loading
+  getThumbnail(): Observable<Bitstream> {
+    return this.bitstreamDataService.getThumbnailFor(this.dso).pipe(
+      getFirstSucceededRemoteDataPayload()
+    );
+  }
 }

src/app/shared/testing/test-module.ts

@@ -1,6 +1,6 @@
 import {CUSTOM_ELEMENTS_SCHEMA, NgModule} from '@angular/core';
 import { QueryParamsDirectiveStub } from './query-params-directive-stub';
-import { MySimpleItemActionComponent } from '../../+item-page/edit-item-page/simple-item-action/abstract-simple-item-action.component.spec';
+// import { MySimpleItemActionComponent } from '../../+item-page/edit-item-page/simple-item-action/abstract-simple-item-action.component.spec';
 import {CommonModule} from '@angular/common';
 import {SharedModule} from '../shared.module';
 import { RouterLinkDirectiveStub } from './router-link-directive-stub';
@@ -19,7 +19,7 @@ import { NgComponentOutletDirectiveStub } from './ng-component-outlet-directive-
   ],
   declarations: [
     QueryParamsDirectiveStub,
-    MySimpleItemActionComponent,
+    // MySimpleItemActionComponent,
     RouterLinkDirectiveStub,
     NgComponentOutletDirectiveStub
   ], schemas: [

src/app/shared/utils/follow-link-config.model.ts

@@ -0,0 +1,20 @@
+import { FindListOptions } from '../../core/data/request.models';
+import { HALResource } from '../../core/shared/hal-resource.model';
+
+export class FollowLinkConfig<R extends HALResource> {
+  name: keyof R['_links'];
+  findListOptions?: FindListOptions;
+  linksToFollow?: Array<FollowLinkConfig<any>>;
+}
+
+export const followLink = <R extends HALResource>(
+  linkName: keyof R['_links'],
+  findListOptions?: FindListOptions,
+  ...linksToFollow: Array<FollowLinkConfig<any>>
+): FollowLinkConfig<R> => {
+  return {
+    name: linkName,
+    findListOptions,
+    linksToFollow
+  }
+};

src/app/submission/objects/submission-objects.effects.spec.ts

@@ -109,8 +109,8 @@ describe('SubmissionObjectEffects test suite', () => {
       const mappedActions = [];
       (submissionDefinitionResponse.sections as SubmissionSectionModel[])
         .forEach((sectionDefinition: SubmissionSectionModel) => {
-          const sectionId = sectionDefinition._links.self.substr(sectionDefinition._links.self.lastIndexOf('/') + 1);
+          const sectionId = sectionDefinition._links.self.href.substr(sectionDefinition._links.self.href.lastIndexOf('/') + 1);
-          const config = sectionDefinition._links.config || '';
+          const config = sectionDefinition._links.config.href || '';
           const enabled = (sectionDefinition.mandatory);
           const sectionData = {};
           const sectionErrors = null;

src/app/submission/objects/submission-objects.effects.ts

@@ -57,8 +57,8 @@ export class SubmissionObjectEffects {
       const definition = action.payload.submissionDefinition;
       const mappedActions = [];
       definition.sections.page.forEach((sectionDefinition: SubmissionSectionModel) => {
-        const sectionId = sectionDefinition._links.self.substr(sectionDefinition._links.self.lastIndexOf('/') + 1);
+        const sectionId = sectionDefinition._links.self.href.substr(sectionDefinition._links.self.href.lastIndexOf('/') + 1);
-        const config = sectionDefinition._links.config || '';
+        const config = sectionDefinition._links.config.href || '';
         const enabled = (sectionDefinition.mandatory) || (isNotEmpty(action.payload.sections) && action.payload.sections.hasOwnProperty(sectionId));
         const sectionData = (isNotUndefined(action.payload.sections) && isNotUndefined(action.payload.sections[sectionId])) ? action.payload.sections[sectionId] : Object.create(null);
         const sectionErrors = null;

src/app/submission/sections/license/section-license.component.ts

@@ -134,7 +134,7 @@ export class SubmissionSectionLicenseComponent extends SectionModelComponent {
 
     this.licenseText$ = this.collectionDataService.findById(this.collectionId).pipe(
       filter((collectionData: RemoteData<Collection>) => isNotUndefined((collectionData.payload))),
-      flatMap((collectionData: RemoteData<Collection>) => collectionData.payload.license),
+      flatMap((collectionData: RemoteData<Collection>) => (collectionData.payload as any).license),
       find((licenseData: RemoteData<License>) => isNotUndefined((licenseData.payload))),
       map((licenseData: RemoteData<License>) => licenseData.payload.text),
       startWith(''));

src/app/submission/sections/upload/section-upload.component.ts

@@ -2,6 +2,7 @@ import { ChangeDetectorRef, Component, Inject } from '@angular/core';
 
 import { BehaviorSubject, combineLatest as observableCombineLatest, Observable, Subscription} from 'rxjs';
 import { distinctUntilChanged, filter, find, flatMap, map, reduce, take, tap } from 'rxjs/operators';
+import { followLink } from '../../../shared/utils/follow-link-config.model';
 
 import { SectionModelComponent } from '../models/section.model';
 import { hasValue, isNotEmpty, isNotUndefined, isUndefined } from '../../../shared/empty.util';
@@ -160,13 +161,11 @@ export class SubmissionSectionUploadComponent extends SectionModelComponent {
         filter((submissionObject: SubmissionObjectEntry) => isNotUndefined(submissionObject) && !submissionObject.isLoading),
         filter((submissionObject: SubmissionObjectEntry) => isUndefined(this.collectionId) || this.collectionId !== submissionObject.collection),
         tap((submissionObject: SubmissionObjectEntry) => this.collectionId = submissionObject.collection),
-        flatMap((submissionObject: SubmissionObjectEntry) => this.collectionDataService.findById(submissionObject.collection)),
+        flatMap((submissionObject: SubmissionObjectEntry) => this.collectionDataService.findById(submissionObject.collection, followLink('defaultAccessConditions'))),
         filter((rd: RemoteData<Collection>) => isNotUndefined((rd.payload))),
         tap((collectionRemoteData: RemoteData<Collection>) => this.collectionName = collectionRemoteData.payload.name),
         flatMap((collectionRemoteData: RemoteData<Collection>) => {
-          return this.resourcePolicyService.findByHref(
+          return this.resourcePolicyService.findByHref((collectionRemoteData.payload as any).defaultAccessConditions);
-            (collectionRemoteData.payload as any)._links.defaultAccessConditions
-          );
         }),
         filter((defaultAccessConditionsRemoteData: RemoteData<ResourcePolicy>) =>
           defaultAccessConditionsRemoteData.hasSucceeded),