Use of embed sizes in the ComCol tree

src/app/community-list-page/community-list-service.ts

@@ -19,6 +19,7 @@ import { CommunityListState } from './community-list.reducer';
 import { getCommunityPageRoute } from '../+community-page/community-page-routing-paths';
 import { getCollectionPageRoute } from '../+collection-page/collection-page-routing-paths';
 import { getFirstSucceededRemoteData, getFirstCompletedRemoteData } from '../core/shared/operators';
+import { followLink } from '../shared/utils/follow-link-config.model';
 
 /**
  * Each node in the tree is represented by a flatNode which contains info about the node itself and its position and
@@ -101,7 +102,7 @@ const communityListStateSelector = (state: AppState) => state.communityList;
 const expandedNodesSelector = createSelector(communityListStateSelector, (communityList: CommunityListState) => communityList.expandedNodes);
 const loadingNodeSelector = createSelector(communityListStateSelector, (communityList: CommunityListState) => communityList.loadingNode);
 
-export const MAX_COMCOLS_PER_PAGE = 50;
+export const MAX_COMCOLS_PER_PAGE = 20;
 
 /**
  * Service class for the community list, responsible for the creating of the flat list used by communityList dataSource
@@ -115,6 +116,10 @@ export class CommunityListService {
               private store: Store<any>) {
   }
 
+  private configOnePage: FindListOptions = Object.assign(new FindListOptions(), {
+    elementsPerPage: 1
+  });
+
   saveCommunityListStateToStore(expandedNodes: FlatNode[], loadingNode: FlatNode): void {
     this.store.dispatch(new CommunityListSaveAction(expandedNodes, loadingNode));
   }
@@ -162,16 +167,19 @@ export class CommunityListService {
    */
   private getTopCommunities(options: FindListOptions): Observable<PaginatedList<Community>> {
     return this.communityDataService.findTop({
-      currentPage: options.currentPage,
-      elementsPerPage: MAX_COMCOLS_PER_PAGE,
-      sort: {
-        field: options.sort.field,
-        direction: options.sort.direction
-      }
-    }).pipe(
-      getFirstSucceededRemoteData(),
-      map((results) => results.payload),
-    );
+        currentPage: options.currentPage,
+        elementsPerPage: MAX_COMCOLS_PER_PAGE,
+        sort: {
+          field: options.sort.field,
+          direction: options.sort.direction
+        }
+      },
+      followLink('subcommunities', this.configOnePage, true, true),
+      followLink('collections', this.configOnePage, true, true))
+      .pipe(
+        getFirstSucceededRemoteData(),
+        map((results) => results.payload),
+      );
   }
 
   /**
@@ -231,9 +239,11 @@ export class CommunityListService {
       let subcoms = [];
       for (let i = 1; i <= currentCommunityPage; i++) {
         const nextSetOfSubcommunitiesPage = this.communityDataService.findByParent(community.uuid, {
-          elementsPerPage: MAX_COMCOLS_PER_PAGE,
-          currentPage: i
-        })
+            elementsPerPage: MAX_COMCOLS_PER_PAGE,
+            currentPage: i
+          },
+          followLink('subcommunities', this.configOnePage, true, true),
+          followLink('collections', this.configOnePage, true, true))
           .pipe(
             getFirstCompletedRemoteData(),
             switchMap((rd: RemoteData<PaginatedList<Community>>) => {
@@ -289,7 +299,7 @@ export class CommunityListService {
   public getIsExpandable(community: Community): Observable<boolean> {
     let hasSubcoms$: Observable<boolean>;
     let hasColls$: Observable<boolean>;
-    hasSubcoms$ = this.communityDataService.findByParent(community.uuid, { elementsPerPage: 1 })
+    hasSubcoms$ = this.communityDataService.findByParent(community.uuid, this.configOnePage)
       .pipe(
         map((rd: RemoteData<PaginatedList<Community>>) => {
           if (hasValue(rd) && hasValue(rd.payload)) {
@@ -300,7 +310,7 @@ export class CommunityListService {
         }),
       );
 
-    hasColls$ = this.collectionDataService.findByParent(community.uuid, { elementsPerPage: 1 })
+    hasColls$ = this.collectionDataService.findByParent(community.uuid, this.configOnePage)
       .pipe(
         map((rd: RemoteData<PaginatedList<Collection>>) => {
           if (hasValue(rd) && hasValue(rd.payload)) {

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

@@ -18,6 +18,7 @@ import { BitstreamDataService } from './bitstream-data.service';
 import { NoContent } from '../shared/NoContent.model';
 import { createFailedRemoteDataObject$ } from '../../shared/remote-data.utils';
 import { URLCombiner } from '../url-combiner/url-combiner';
+import { FollowLinkConfig } from '../../shared/utils/follow-link-config.model';
 
 export abstract class ComColDataService<T extends Community | Collection> extends DataService<T> {
   protected abstract cds: CommunityDataService;
@@ -66,11 +67,11 @@ export abstract class ComColDataService<T extends Community | Collection> extend
 
   protected abstract getFindByParentHref(parentUUID: string): Observable<string>;
 
-  public findByParent(parentUUID: string, options: FindListOptions = {}): Observable<RemoteData<PaginatedList<T>>> {
+  public findByParent(parentUUID: string, options: FindListOptions = {}, ...linksToFollow: FollowLinkConfig<T>[]): Observable<RemoteData<PaginatedList<T>>> {
     const href$ = this.getFindByParentHref(parentUUID).pipe(
       map((href: string) => this.buildHrefFromFindOptions(href, options))
     );
-    return this.findAllByHref(href$);
+    return this.findAllByHref(href$, options, true, true, ...linksToFollow);
   }
 
   /**

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

@@ -19,6 +19,7 @@ import { RemoteData } from './remote-data';
 import { FindListOptions } from './request.models';
 import { RequestService } from './request.service';
 import { BitstreamDataService } from './bitstream-data.service';
+import { FollowLinkConfig } from '../../shared/utils/follow-link-config.model';
 
 @Injectable()
 @dataService(COMMUNITY)
@@ -45,9 +46,9 @@ export class CommunityDataService extends ComColDataService<Community> {
     return this.halService.getEndpoint(this.linkPath);
   }
 
-  findTop(options: FindListOptions = {}): Observable<RemoteData<PaginatedList<Community>>> {
+  findTop(options: FindListOptions = {}, ...linksToFollow: FollowLinkConfig<Community>[]): Observable<RemoteData<PaginatedList<Community>>> {
     const hrefObs = this.getFindAllHref(options, this.topLinkPath);
-    return this.findAllByHref(hrefObs, undefined);
+    return this.findAllByHref(hrefObs, undefined, true, true, ...linksToFollow);
   }
 
   protected getFindByParentHref(parentUUID: string): Observable<string> {

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

@@ -193,6 +193,16 @@ describe('DataService', () => {
       });
     });
 
+    it('should include single linksToFollow as embed and its size', () => {
+      const expected = `${endpoint}?embed.size=bundles=5&embed=bundles`;
+      const config: FindListOptions = Object.assign(new FindListOptions(), {
+        elementsPerPage: 5
+      });
+      (service as any).getFindAllHref({}, null, followLink('bundles', config,  true, true, true)).subscribe((value) => {
+        expect(value).toBe(expected);
+      });
+    });
+
     it('should include multiple linksToFollow as embed', () => {
       const expected = `${endpoint}?embed=bundles&embed=owningCollection&embed=templateItemOf`;
 
@@ -201,6 +211,18 @@ describe('DataService', () => {
       });
     });
 
+    it('should include multiple linksToFollow as embed and its sizes if given', () => {
+      const expected = `${endpoint}?embed=bundles&embed.size=owningCollection=2&embed=owningCollection&embed=templateItemOf`;
+
+      const config: FindListOptions = Object.assign(new FindListOptions(), {
+        elementsPerPage: 2
+      });
+
+      (service as any).getFindAllHref({}, null, followLink('bundles'), followLink('owningCollection', config, true, true, true), followLink('templateItemOf')).subscribe((value) => {
+        expect(value).toBe(expected);
+      });
+    });
+
     it('should not include linksToFollow with shouldEmbed = false', () => {
       const expected = `${endpoint}?embed=templateItemOf`;
 
@@ -216,6 +238,16 @@ describe('DataService', () => {
         expect(value).toBe(expected);
       });
     });
+
+    it('should include nested linksToFollow 2lvl and nested embed\'s size', () => {
+      const expected = `${endpoint}?embed.size=owningCollection/itemtemplate=4&embed=owningCollection/itemtemplate`;
+      const config: FindListOptions = Object.assign(new FindListOptions(), {
+        elementsPerPage: 4
+      });
+      (service as any).getFindAllHref({}, null, followLink('owningCollection', undefined, true, true, true, followLink('itemtemplate', config, true, true, true))).subscribe((value) => {
+        expect(value).toBe(expected);
+      });
+    });
   });
 
   describe('getIDHref', () => {

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

@@ -215,10 +215,19 @@ export abstract class DataService<T extends CacheableObject> implements UpdateDa
    */
   protected addEmbedParams(href: string, args: string[], ...linksToFollow: FollowLinkConfig<T>[]) {
     linksToFollow.forEach((linkToFollow: FollowLinkConfig<T>) => {
-      if (linkToFollow !== undefined && linkToFollow.shouldEmbed) {
+      if (hasValue(linkToFollow) && linkToFollow.shouldEmbed) {
         const embedString = 'embed=' + String(linkToFollow.name);
-        const embedWithNestedString = this.addNestedEmbeds(embedString, ...linkToFollow.linksToFollow);
-        args = this.addHrefArg(href, args, embedWithNestedString);
+        // Add the embeds size if given in the FollowLinkConfig.FindListOptions
+        if (hasValue(linkToFollow.findListOptions) && hasValue(linkToFollow.findListOptions.elementsPerPage)) {
+          args = this.addHrefArg(href, args,
+            'embed.size=' + String(linkToFollow.name) + '=' + linkToFollow.findListOptions.elementsPerPage);
+        }
+        // Adds the nested embeds and their size if given
+        if (isNotEmpty(linkToFollow.linksToFollow)) {
+          args = this.addNestedEmbeds(embedString, href, args, ...linkToFollow.linksToFollow);
+        } else {
+          args = this.addHrefArg(href, args, embedString);
+        }
       }
     });
     return args;
@@ -243,21 +252,30 @@ export abstract class DataService<T extends CacheableObject> implements UpdateDa
   }
 
   /**
-   * Add the nested followLinks to the embed param, recursively, separated by a /
+   * Add the nested followLinks to the embed param, separated by a /, and their sizes, recursively
    * @param embedString     embedString so far (recursive)
+   * @param href            The href the params are to be added to
+   * @param args            params for the query string
    * @param linksToFollow   links we want to embed in query string if shouldEmbed is true
    */
-  protected addNestedEmbeds(embedString: string, ...linksToFollow: FollowLinkConfig<T>[]): string {
+  protected addNestedEmbeds(embedString: string, href: string, args: string[], ...linksToFollow: FollowLinkConfig<T>[]): string[] {
     let nestEmbed = embedString;
     linksToFollow.forEach((linkToFollow: FollowLinkConfig<T>) => {
-      if (linkToFollow !== undefined && linkToFollow.shouldEmbed) {
+      if (hasValue(linkToFollow) && linkToFollow.shouldEmbed) {
         nestEmbed = nestEmbed + '/' + String(linkToFollow.name);
-        if (linkToFollow.linksToFollow !== undefined) {
-          nestEmbed = this.addNestedEmbeds(nestEmbed, ...linkToFollow.linksToFollow);
+        // Add the nested embeds size if given in the FollowLinkConfig.FindListOptions
+        if (hasValue(linkToFollow.findListOptions) && hasValue(linkToFollow.findListOptions.elementsPerPage)) {
+          const nestedEmbedSize = 'embed.size=' + nestEmbed.split('=')[1] + '=' + linkToFollow.findListOptions.elementsPerPage;
+          args = this.addHrefArg(href, args, nestedEmbedSize);
+        }
+        if (hasValue(linkToFollow.linksToFollow) && isNotEmpty(linkToFollow.linksToFollow)) {
+          args = this.addNestedEmbeds(nestEmbed, href, args, ...linkToFollow.linksToFollow);
+        } else {
+          args = this.addHrefArg(href, args, nestEmbed);
         }
       }
     });
-    return nestEmbed;
+    return args;
   }
 
   /**

src/app/core/data/dspace-rest-response-parsing.service.ts

@@ -15,7 +15,8 @@ import { Injectable } from '@angular/core';
 import { ResponseParsingService } from './parsing.service';
 import { ParsedResponse } from '../cache/response.models';
 import { RestRequestMethod } from './rest-request-method';
-import { getUrlWithoutEmbedParams } from '../index/index.selectors';
+import { getUrlWithoutEmbedParams, getEmbedSizeParams } from '../index/index.selectors';
+import { URLCombiner } from '../url-combiner/url-combiner';
 
 /* tslint:disable:max-classes-per-file */
 
@@ -86,6 +87,8 @@ export class DspaceRestResponseParsingService implements ResponseParsingService
   }
 
   public process<ObjectDomain>(data: any, request: RestRequest, alternativeURL?: string): any {
+    const embedSizeParams = getEmbedSizeParams(request.href);
+
     if (isNotEmpty(data)) {
       if (hasNoValue(data) || (typeof data !== 'object')) {
         return data;
@@ -100,7 +103,13 @@ export class DspaceRestResponseParsingService implements ResponseParsingService
             .keys(data._embedded)
             .filter((property) => data._embedded.hasOwnProperty(property))
             .forEach((property) => {
-              this.process<ObjectDomain>(data._embedded[property], request, data._links[property].href);
+              let embedAltUrl = data._links[property].href;
+              const match = embedSizeParams
+                .find((param: { name: string, size: number }) => param.name === property);
+              if (hasValue(match)) {
+                embedAltUrl = new URLCombiner(embedAltUrl, `?size=${match.size}`).toString();
+              }
+              this.process<ObjectDomain>(data._embedded[property], request, embedAltUrl);
             });
         }
 

src/app/core/index/index.selectors.spec.ts

@@ -1,4 +1,5 @@
-import { getUrlWithoutEmbedParams } from './index.selectors';
+import { getEmbedSizeParams, getUrlWithoutEmbedParams } from './index.selectors';
+
 
 describe(`index selectors`, () => {
 
@@ -29,4 +30,38 @@ describe(`index selectors`, () => {
 
   });
 
+  describe(`getEmbedSizeParams`, () => {
+
+    it(`url with single embed size param => should return list with ['subcommunities' - size]`, () => {
+      const source = 'https://rest.api/core/communities/search/top?page=0&size=50&sort=dc.title,ASC&embed.size=subcommunities=5&embed=subcommunities';
+      const result = getEmbedSizeParams(source);
+      expect(result).toHaveSize(1);
+      expect(result[0]).toEqual({name: 'subcommunities', size: 5});
+    });
+
+    it(`url with multiple embed size param => should return list with {name, size}`, () => {
+      const source = 'https://rest.api/core/communities/search/top?page=0&size=50&sort=dc.title,ASC&embed.size=subcommunities=5&embed=subcommunities&embed.size=collections=1&embed=collections';
+      const result = getEmbedSizeParams(source);
+      expect(result).toHaveSize(2);
+      expect(result[0]).toEqual({name: 'subcommunities', size: 5});
+      expect(result[1]).toEqual({name: 'collections', size: 1});
+    });
+
+    it(`url without params => should return empty list`, () => {
+      const source = 'https://rest.api/core/collections/uuid';
+      expect(getEmbedSizeParams(source)).toHaveSize(0);
+    });
+
+    it(`url without embed size params => should return empty list`, () => {
+      const source = 'https://rest.api/core/collections/uuid?page=0&size=50';
+      expect(getEmbedSizeParams(source)).toHaveSize(0);
+    });
+
+    it(`undefined or null url => should return empty list`, () => {
+      expect(getEmbedSizeParams(undefined)).toHaveSize(0);
+      expect(getEmbedSizeParams(null)).toHaveSize(0);
+    });
+
+  });
+
 });

src/app/core/index/index.selectors.ts

@@ -24,7 +24,7 @@ export const getUrlWithoutEmbedParams = (url: string): string => {
     if (isNotEmpty(parsed.query)) {
       const parts = parsed.query.split(/[?|&]/)
         .filter((part: string) => isNotEmpty(part))
-        .filter((part: string) => !part.startsWith('embed='));
+        .filter((part: string) => !(part.startsWith('embed=') || part.startsWith('embed.size=')));
       let args = '';
       if (isNotEmpty(parts)) {
         args = `?${parts.join('&')}`;
@@ -37,6 +37,27 @@ export const getUrlWithoutEmbedParams = (url: string): string => {
   return url;
 };
 
+/**
+ * Parse the embed size params from a url
+ * @param url The url to parse
+ */
+export const getEmbedSizeParams = (url: string): { name: string, size: number }[] => {
+  if (isNotEmpty(url)) {
+    const parsed = parse(url);
+    if (isNotEmpty(parsed.query)) {
+      return parsed.query.split(/[?|&]/)
+        .filter((part: string) => isNotEmpty(part))
+        .map((part: string) => part.match(/^embed.size=([^=]+)=(\d+)$/))
+        .filter((matches: RegExpMatchArray) => hasValue(matches) && hasValue(matches[1]) && hasValue(matches[2]))
+        .map((matches: RegExpMatchArray) => {
+          return { name: matches[1], size: Number(matches[2]) };
+        });
+    }
+  }
+
+  return [];
+};
+
 /**
  * Return the MetaIndexState based on the CoreSate
  *