83783: Show owning and mapped collections on item page

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

@@ -208,10 +208,20 @@ export class CollectionDataService extends ComColDataService<Collection> {
   }
 
   /**
-   * Returns {@link RemoteData} of {@link Collection} that is the owing collection of the given item
+   * Returns {@link RemoteData} of {@link Collection} that is the owning collection of the given item
    * @param item  Item we want the owning collection of
    */
   findOwningCollectionFor(item: Item): Observable<RemoteData<Collection>> {
     return this.findByHref(item._links.owningCollection.href);
   }
+
+  /**
+   * Get a list of mapped collections for the given item.
+   * @param item  Item for which the mapped collections should be retrieved.
+   * @param findListOptions Pagination and search options.
+   */
+  findMappedCollectionsFor(item: Item, findListOptions?: FindListOptions): Observable<RemoteData<PaginatedList<Collection>>> {
+    return this.findAllByHref(item._links.mappedCollections.href, findListOptions);
+  }
+
 }

src/app/item-page/field-components/collections/collections.component.html

@@ -1,7 +1,21 @@
-<ds-metadata-field-wrapper *ngIf="(this.collectionsRD$ | async)?.hasSucceeded" [label]="label | translate">
+<ds-metadata-field-wrapper [label]="label | translate">
     <div class="collections">
-        <a *ngFor="let collection of (this.collectionsRD$ | async)?.payload?.page; let last=last;" [routerLink]="['/collections', collection.id]">
+        <a *ngFor="let collection of (this.collections$ | async); let last=last;" [routerLink]="['/collections', collection.id]">
             <span>{{collection?.name}}</span><span *ngIf="!last" [innerHTML]="separator"></span>
         </a>
     </div>
+
+    <div *ngIf="isLoading$ | async">
+        {{'item.page.collections.loading' | translate}}
+    </div>
+
+    <a
+        *ngIf="!(isLoading$ | async) && (hasMore$ | async)"
+        (click)="$event.preventDefault(); handleLoadMore()"
+        class="load-more-btn btn btn-sm btn-outline-secondary"
+        role="button"
+        href="#"
+    >
+        {{'item.page.collections.load-more' | translate}}
+    </a>
 </ds-metadata-field-wrapper>

src/app/item-page/field-components/collections/collections.component.spec.ts

@@ -9,46 +9,45 @@ import { Item } from '../../../core/shared/item.model';
 import { getMockRemoteDataBuildService } from '../../../shared/mocks/remote-data-build.service.mock';
 import { createFailedRemoteDataObject$, createSuccessfulRemoteDataObject$ } from '../../../shared/remote-data.utils';
 import { CollectionsComponent } from './collections.component';
+import { FindListOptions } from '../../../core/data/request.models';
+import { buildPaginatedList, PaginatedList } from '../../../core/data/paginated-list.model';
+import { PageInfo } from '../../../core/shared/page-info.model';
 
-let collectionsComponent: CollectionsComponent;
-let fixture: ComponentFixture<CollectionsComponent>;
-
-let collectionDataServiceStub;
-
-const mockCollection1: Collection = Object.assign(new Collection(), {
-  metadata: {
-    'dc.description.abstract': [
-      {
-        language: 'en_US',
-        value: 'Short description'
-      }
-    ]
-  },
-  _links: {
-    self: { href: 'collection-selflink' }
-  }
+const createMockCollection = (id: string) => Object.assign(new Collection(), {
+  id: id,
+  name: `collection-${id}`,
 });
 
-const succeededMockItem: Item = Object.assign(new Item(), {owningCollection: createSuccessfulRemoteDataObject$(mockCollection1)});
-const failedMockItem: Item = Object.assign(new Item(), {owningCollection: createFailedRemoteDataObject$('error', 500)});
+const mockItem: Item = new Item();
 
 describe('CollectionsComponent', () => {
-  collectionDataServiceStub = {
-    findOwningCollectionFor(item: Item) {
-      if (item === succeededMockItem) {
-        return createSuccessfulRemoteDataObject$(mockCollection1);
-      } else {
-        return createFailedRemoteDataObject$('error', 500);
-      }
-    }
-  };
+  let collectionDataService;
+
+  let mockCollection1: Collection;
+  let mockCollection2: Collection;
+  let mockCollection3: Collection;
+  let mockCollection4: Collection;
+
+  let component: CollectionsComponent;
+  let fixture: ComponentFixture<CollectionsComponent>;
+
   beforeEach(waitForAsync(() => {
+    collectionDataService = jasmine.createSpyObj([
+      'findOwningCollectionFor',
+      'findMappedCollectionsFor',
+    ]);
+
+    mockCollection1 = createMockCollection('c1');
+    mockCollection2 = createMockCollection('c2');
+    mockCollection3 = createMockCollection('c3');
+    mockCollection4 = createMockCollection('c4');
+
     TestBed.configureTestingModule({
       imports: [TranslateModule.forRoot()],
       declarations: [ CollectionsComponent ],
       providers: [
         { provide: RemoteDataBuildService, useValue: getMockRemoteDataBuildService()},
-        { provide: CollectionDataService, useValue: collectionDataServiceStub },
+        { provide: CollectionDataService, useValue: collectionDataService },
       ],
 
       schemas: [ NO_ERRORS_SCHEMA ]
@@ -59,33 +58,264 @@ describe('CollectionsComponent', () => {
 
   beforeEach(waitForAsync(() => {
     fixture = TestBed.createComponent(CollectionsComponent);
-    collectionsComponent = fixture.componentInstance;
-    collectionsComponent.label = 'test.test';
-    collectionsComponent.separator = '<br/>';
-
+    component = fixture.componentInstance;
+    component.item = mockItem;
+    component.label = 'test.test';
+    component.separator = '<br/>';
+    component.pageSize = 2;
   }));
 
-  describe('When the requested item request has succeeded', () => {
+  describe('when the item has only an owning collection', () => {
+    let mockPage1: PaginatedList<Collection>;
+
     beforeEach(() => {
-      collectionsComponent.item = succeededMockItem;
+      mockPage1 = buildPaginatedList(Object.assign(new PageInfo(), {
+        currentPage: 1,
+        elementsPerPage: 2,
+        totalPages: 0,
+        totalElements: 0,
+      }), []);
+
+      collectionDataService.findOwningCollectionFor.and.returnValue(createSuccessfulRemoteDataObject$(mockCollection1));
+      collectionDataService.findMappedCollectionsFor.and.returnValue(createSuccessfulRemoteDataObject$(mockPage1));
       fixture.detectChanges();
     });
 
-    it('should show the collection', () => {
-      const collectionField = fixture.debugElement.query(By.css('ds-metadata-field-wrapper div.collections'));
-      expect(collectionField).not.toBeNull();
+    it('should display the owning collection', () => {
+      const collectionFields = fixture.debugElement.queryAll(By.css('ds-metadata-field-wrapper div.collections a'));
+      const loadMoreBtn = fixture.debugElement.query(By.css('ds-metadata-field-wrapper .load-more-btn'));
+
+      expect(collectionDataService.findOwningCollectionFor).toHaveBeenCalledOnceWith(mockItem);
+      expect(collectionDataService.findMappedCollectionsFor).toHaveBeenCalledOnceWith(mockItem, Object.assign(new FindListOptions(), {
+        elementsPerPage: 2,
+        currentPage: 1,
+      }));
+
+      expect(collectionFields.length).toBe(1);
+      expect(collectionFields[0].nativeElement.textContent).toEqual('collection-c1');
+
+      expect(component.lastPage$.getValue()).toBe(1);
+      expect(component.hasMore$.getValue()).toBe(false);
+      expect(component.isLoading$.getValue()).toBe(false);
+
+      expect(loadMoreBtn).toBeNull();
     });
   });
 
-  describe('When the requested item request has failed', () => {
+  describe('when the item has an owning collection and one mapped collection', () => {
+    let mockPage1: PaginatedList<Collection>;
+
     beforeEach(() => {
-      collectionsComponent.item = failedMockItem;
+      mockPage1 = buildPaginatedList(Object.assign(new PageInfo(), {
+        currentPage: 1,
+        elementsPerPage: 2,
+        totalPages: 1,
+        totalElements: 1,
+      }), [mockCollection2]);
+
+      collectionDataService.findOwningCollectionFor.and.returnValue(createSuccessfulRemoteDataObject$(mockCollection1));
+      collectionDataService.findMappedCollectionsFor.and.returnValue(createSuccessfulRemoteDataObject$(mockPage1));
       fixture.detectChanges();
     });
 
-    it('should not show the collection', () => {
-      const collectionField = fixture.debugElement.query(By.css('ds-metadata-field-wrapper div.collections'));
-      expect(collectionField).toBeNull();
+    it('should display the owning collection and the mapped collection', () => {
+      const collectionFields = fixture.debugElement.queryAll(By.css('ds-metadata-field-wrapper div.collections a'));
+      const loadMoreBtn = fixture.debugElement.query(By.css('ds-metadata-field-wrapper .load-more-btn'));
+
+      expect(collectionDataService.findOwningCollectionFor).toHaveBeenCalledOnceWith(mockItem);
+      expect(collectionDataService.findMappedCollectionsFor).toHaveBeenCalledOnceWith(mockItem, Object.assign(new FindListOptions(), {
+        elementsPerPage: 2,
+        currentPage: 1,
+      }));
+
+      expect(collectionFields.length).toBe(2);
+      expect(collectionFields[0].nativeElement.textContent).toEqual('collection-c1');
+      expect(collectionFields[1].nativeElement.textContent).toEqual('collection-c2');
+
+      expect(component.lastPage$.getValue()).toBe(1);
+      expect(component.hasMore$.getValue()).toBe(false);
+      expect(component.isLoading$.getValue()).toBe(false);
+
+      expect(loadMoreBtn).toBeNull();
+    });
+  });
+
+  describe('when the item has an owning collection and multiple mapped collections', () => {
+    let mockPage1: PaginatedList<Collection>;
+    let mockPage2: PaginatedList<Collection>;
+
+    beforeEach(() => {
+      mockPage1 = buildPaginatedList(Object.assign(new PageInfo(), {
+        currentPage: 1,
+        elementsPerPage: 2,
+        totalPages: 2,
+        totalElements: 3,
+      }), [mockCollection2, mockCollection3]);
+
+      mockPage2 = buildPaginatedList(Object.assign(new PageInfo(), {
+        currentPage: 2,
+        elementsPerPage: 2,
+        totalPages: 2,
+        totalElements: 1,
+      }), [mockCollection4]);
+
+      collectionDataService.findOwningCollectionFor.and.returnValue(createSuccessfulRemoteDataObject$(mockCollection1));
+      collectionDataService.findMappedCollectionsFor.and.returnValues(
+        createSuccessfulRemoteDataObject$(mockPage1),
+        createSuccessfulRemoteDataObject$(mockPage2),
+      );
+      fixture.detectChanges();
+    });
+
+    it('should display the owning collection, two mapped collections and a load more button', () => {
+      const collectionFields = fixture.debugElement.queryAll(By.css('ds-metadata-field-wrapper div.collections a'));
+      const loadMoreBtn = fixture.debugElement.query(By.css('ds-metadata-field-wrapper .load-more-btn'));
+
+      expect(collectionDataService.findOwningCollectionFor).toHaveBeenCalledOnceWith(mockItem);
+      expect(collectionDataService.findMappedCollectionsFor).toHaveBeenCalledOnceWith(mockItem, Object.assign(new FindListOptions(), {
+        elementsPerPage: 2,
+        currentPage: 1,
+      }));
+
+      expect(collectionFields.length).toBe(3);
+      expect(collectionFields[0].nativeElement.textContent).toEqual('collection-c1');
+      expect(collectionFields[1].nativeElement.textContent).toEqual('collection-c2');
+      expect(collectionFields[2].nativeElement.textContent).toEqual('collection-c3');
+
+      expect(component.lastPage$.getValue()).toBe(1);
+      expect(component.hasMore$.getValue()).toBe(true);
+      expect(component.isLoading$.getValue()).toBe(false);
+
+      expect(loadMoreBtn).toBeTruthy();
+    });
+
+    describe('when the load more button is clicked', () => {
+      beforeEach(() => {
+        const loadMoreBtn = fixture.debugElement.query(By.css('ds-metadata-field-wrapper .load-more-btn'));
+        loadMoreBtn.nativeElement.click();
+        fixture.detectChanges();
+      });
+
+      it('should display the owning collection and three mapped collections', () => {
+        const collectionFields = fixture.debugElement.queryAll(By.css('ds-metadata-field-wrapper div.collections a'));
+        const loadMoreBtn = fixture.debugElement.query(By.css('ds-metadata-field-wrapper .load-more-btn'));
+
+        expect(collectionDataService.findOwningCollectionFor).toHaveBeenCalledOnceWith(mockItem);
+        expect(collectionDataService.findMappedCollectionsFor).toHaveBeenCalledTimes(2);
+        expect(collectionDataService.findMappedCollectionsFor).toHaveBeenCalledWith(mockItem, Object.assign(new FindListOptions(), {
+          elementsPerPage: 2,
+          currentPage: 1,
+        }));
+        expect(collectionDataService.findMappedCollectionsFor).toHaveBeenCalledWith(mockItem, Object.assign(new FindListOptions(), {
+          elementsPerPage: 2,
+          currentPage: 2,
+        }));
+
+        expect(collectionFields.length).toBe(4);
+        expect(collectionFields[0].nativeElement.textContent).toEqual('collection-c1');
+        expect(collectionFields[1].nativeElement.textContent).toEqual('collection-c2');
+        expect(collectionFields[2].nativeElement.textContent).toEqual('collection-c3');
+        expect(collectionFields[3].nativeElement.textContent).toEqual('collection-c4');
+
+        expect(component.lastPage$.getValue()).toBe(2);
+        expect(component.hasMore$.getValue()).toBe(false);
+        expect(component.isLoading$.getValue()).toBe(false);
+
+        expect(loadMoreBtn).toBeNull();
       });
     });
   });
+
+  describe('when the request for the owning collection fails', () => {
+    let mockPage1: PaginatedList<Collection>;
+
+    beforeEach(() => {
+      mockPage1 = buildPaginatedList(Object.assign(new PageInfo(), {
+        currentPage: 1,
+        elementsPerPage: 2,
+        totalPages: 1,
+        totalElements: 1,
+      }), [mockCollection2]);
+
+      collectionDataService.findOwningCollectionFor.and.returnValue(createFailedRemoteDataObject$());
+      collectionDataService.findMappedCollectionsFor.and.returnValue(createSuccessfulRemoteDataObject$(mockPage1));
+      fixture.detectChanges();
+    });
+
+    it('should display the mapped collection only', () => {
+      const collectionFields = fixture.debugElement.queryAll(By.css('ds-metadata-field-wrapper div.collections a'));
+      const loadMoreBtn = fixture.debugElement.query(By.css('ds-metadata-field-wrapper .load-more-btn'));
+
+      expect(collectionDataService.findOwningCollectionFor).toHaveBeenCalledOnceWith(mockItem);
+      expect(collectionDataService.findMappedCollectionsFor).toHaveBeenCalledOnceWith(mockItem, Object.assign(new FindListOptions(), {
+        elementsPerPage: 2,
+        currentPage: 1,
+      }));
+
+      expect(collectionFields.length).toBe(1);
+      expect(collectionFields[0].nativeElement.textContent).toEqual('collection-c2');
+
+      expect(component.lastPage$.getValue()).toBe(1);
+      expect(component.hasMore$.getValue()).toBe(false);
+      expect(component.isLoading$.getValue()).toBe(false);
+
+      expect(loadMoreBtn).toBeNull();
+    });
+  });
+
+  describe('when the request for the mapped collections fails', () => {
+    beforeEach(() => {
+      collectionDataService.findOwningCollectionFor.and.returnValue(createSuccessfulRemoteDataObject$(mockCollection1));
+      collectionDataService.findMappedCollectionsFor.and.returnValue(createFailedRemoteDataObject$());
+      fixture.detectChanges();
+    });
+
+    it('should display the owning collection only', () => {
+      const collectionFields = fixture.debugElement.queryAll(By.css('ds-metadata-field-wrapper div.collections a'));
+      const loadMoreBtn = fixture.debugElement.query(By.css('ds-metadata-field-wrapper .load-more-btn'));
+
+      expect(collectionDataService.findOwningCollectionFor).toHaveBeenCalledOnceWith(mockItem);
+      expect(collectionDataService.findMappedCollectionsFor).toHaveBeenCalledOnceWith(mockItem, Object.assign(new FindListOptions(), {
+        elementsPerPage: 2,
+        currentPage: 1,
+      }));
+
+      expect(collectionFields.length).toBe(1);
+      expect(collectionFields[0].nativeElement.textContent).toEqual('collection-c1');
+
+      expect(component.lastPage$.getValue()).toBe(0);
+      expect(component.hasMore$.getValue()).toBe(true);
+      expect(component.isLoading$.getValue()).toBe(false);
+
+      expect(loadMoreBtn).toBeTruthy();
+    });
+  });
+
+  describe('when both requests fail', () => {
+    beforeEach(() => {
+      collectionDataService.findOwningCollectionFor.and.returnValue(createFailedRemoteDataObject$());
+      collectionDataService.findMappedCollectionsFor.and.returnValue(createFailedRemoteDataObject$());
+      fixture.detectChanges();
+    });
+
+    it('should display no collections', () => {
+      const collectionFields = fixture.debugElement.queryAll(By.css('ds-metadata-field-wrapper div.collections a'));
+      const loadMoreBtn = fixture.debugElement.query(By.css('ds-metadata-field-wrapper .load-more-btn'));
+
+      expect(collectionDataService.findOwningCollectionFor).toHaveBeenCalledOnceWith(mockItem);
+      expect(collectionDataService.findMappedCollectionsFor).toHaveBeenCalledOnceWith(mockItem, Object.assign(new FindListOptions(), {
+        elementsPerPage: 2,
+        currentPage: 1,
+      }));
+
+      expect(collectionFields.length).toBe(0);
+
+      expect(component.lastPage$.getValue()).toBe(0);
+      expect(component.hasMore$.getValue()).toBe(true);
+      expect(component.isLoading$.getValue()).toBe(false);
+
+      expect(loadMoreBtn).toBeTruthy();
+    });
+  });
+
+});

src/app/item-page/field-components/collections/collections.component.ts

@@ -1,14 +1,19 @@
 import { Component, Input, OnInit } from '@angular/core';
-import { Observable } from 'rxjs';
-import { map } from 'rxjs/operators';
+import { BehaviorSubject, combineLatest, Observable } from 'rxjs';
+import {map, scan, startWith, switchMap, tap, withLatestFrom} from 'rxjs/operators';
 import { CollectionDataService } from '../../../core/data/collection-data.service';
-import { PaginatedList, buildPaginatedList } from '../../../core/data/paginated-list.model';
-import { RemoteData } from '../../../core/data/remote-data';
+import { PaginatedList } from '../../../core/data/paginated-list.model';
 
 import { Collection } from '../../../core/shared/collection.model';
 import { Item } from '../../../core/shared/item.model';
-import { PageInfo } from '../../../core/shared/page-info.model';
 import { hasValue } from '../../../shared/empty.util';
+import { FindListOptions } from '../../../core/data/request.models';
+import {
+  getAllCompletedRemoteData,
+  getAllSucceededRemoteDataPayload,
+  getFirstSucceededRemoteDataPayload,
+  getPaginatedListPayload,
+} from '../../../core/shared/operators';
 
 /**
  * This component renders the parent collections section of the item
@@ -27,42 +32,92 @@ export class CollectionsComponent implements OnInit {
 
   separator = '<br/>';
 
-  collectionsRD$: Observable<RemoteData<PaginatedList<Collection>>>;
+  /**
+   * Amount of mapped collections that should be fetched at once.
+   */
+  pageSize = 5;
+
+  /**
+   * Last page of the mapped collections that has been fetched.
+   */
+  lastPage$: BehaviorSubject<number> = new BehaviorSubject<number>(0);
+
+  /**
+   * Push an event to this observable to fetch the next page of mapped collections.
+   * Because this observable is a behavior subject, the first page will be requested
+   * immediately after subscription.
+   */
+  loadMore$: BehaviorSubject<void> = new BehaviorSubject(undefined);
+
+  /**
+   * Whether or not a page of mapped collections is currently being loaded.
+   */
+  isLoading$: BehaviorSubject<boolean> = new BehaviorSubject<boolean>(true);
+
+  /**
+   * Whether or not more pages of mapped collections are available.
+   */
+  hasMore$: BehaviorSubject<boolean> = new BehaviorSubject<boolean>(true);
+
+  /**
+   * All collections that have been retrieved so far. This includes the owning collection,
+   * as well as any number of pages of mapped collections.
+   */
+  collections$: Observable<Collection[]>;
 
   constructor(private cds: CollectionDataService) {
 
   }
 
   ngOnInit(): void {
-    //   this.collections = this.item.parents.payload;
+    const owningCollection$: Observable<Collection> = this.cds.findOwningCollectionFor(this.item).pipe(
+      getFirstSucceededRemoteDataPayload(),
+      startWith(null as Collection),
+    );
 
-    // TODO: this should use parents, but the collections
-    // for an Item aren't returned by the REST API yet,
-    // only the owning collection
-    this.collectionsRD$ = this.cds.findOwningCollectionFor(this.item).pipe(
-      map((rd: RemoteData<Collection>) => {
-        if (hasValue(rd.payload)) {
-          return new RemoteData(
-            rd.timeCompleted,
-            rd.msToLive,
-            rd.lastUpdated,
-            rd.state,
-            rd.errorMessage,
-            buildPaginatedList({
-              elementsPerPage: 10,
-              totalPages: 1,
-              currentPage: 1,
-              totalElements: 1,
-              _links: {
-                self: rd.payload._links.self
-              }
-            } as PageInfo, [rd.payload]),
-            rd.statusCode
-          );
-        } else {
-          return rd as any;
-        }
-      })
+    const mappedCollections$: Observable<Collection[]> = this.loadMore$.pipe(
+      // update isLoading$
+      tap(() => this.isLoading$.next(true)),
+
+      // request next batch of mapped collections
+      withLatestFrom(this.lastPage$),
+      switchMap(([_, lastPage]: [void, number]) => {
+        return this.cds.findMappedCollectionsFor(this.item, Object.assign(new FindListOptions(), {
+          elementsPerPage: this.pageSize,
+          currentPage: lastPage + 1,
+        }));
+      }),
+
+      getAllCompletedRemoteData<PaginatedList<Collection>>(),
+
+      // update isLoading$
+      tap(() => this.isLoading$.next(false)),
+
+      getAllSucceededRemoteDataPayload(),
+
+      // update hasMore$
+      tap((response: PaginatedList<Collection>) => this.hasMore$.next(response.currentPage < response.totalPages)),
+
+      // update lastPage$
+      tap((response: PaginatedList<Collection>) => this.lastPage$.next(response.currentPage)),
+
+      getPaginatedListPayload<Collection>(),
+
+      // add current batch to list of collections
+      scan((prev: Collection[], current: Collection[]) => [...prev, ...current], []),
+
+      startWith([]),
+    ) as Observable<Collection[]>;
+
+    this.collections$ = combineLatest([owningCollection$, mappedCollections$]).pipe(
+      map(([owningCollection, mappedCollections]: [Collection, Collection[]]) => {
+        return [owningCollection, ...mappedCollections].filter(collection => hasValue(collection));
+      }),
     );
   }
+
+  handleLoadMore() {
+    this.loadMore$.next();
+  }
+
 }

src/assets/i18n/en.json5

@@ -1874,6 +1874,10 @@
 
   "item.page.collections": "Collections",
 
+  "item.page.collections.loading": "Loading...",
+
+  "item.page.collections.load-more": "Load more",
+
   "item.page.date": "Date",
 
   "item.page.edit": "Edit this item",