Make no. of communities per pagination / expansion configurable

Adds new config settings for no. of communities to display on the
home page & community-list page.

Resolves DSpace#1749, resolves DSpace#1750

Author: mark-cooper

config/config.example.yml

@@ -175,6 +175,10 @@ browseBy:
   # The absolute lowest year to display in the dropdown (only used when no lowest date can be found for all items)
   defaultLowerLimit: 1900
 
+browseCommunities:
+  communityListPageSize: 20
+  topLevelPageSize: 5
+
 # Item Config
 item:
   edit:

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

@@ -23,6 +23,7 @@ import { followLink } from '../shared/utils/follow-link-config.model';
 import { FlatNode } from './flat-node.model';
 import { ShowMoreFlatNode } from './show-more-flat-node.model';
 import { FindListOptions } from '../core/data/find-list-options.model';
+import { environment } from 'src/environments/environment';
 
 // Helper method to combine an flatten an array of observables of flatNode arrays
 export const combineAndFlatten = (obsList: Observable<FlatNode[]>[]): Observable<FlatNode[]> =>
@@ -80,7 +81,7 @@ 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 = 20;
+export const MAX_COMCOLS_PER_PAGE = environment.browseCommunities.communityListPageSize;
 
 /**
  * Service class for the community list, responsible for the creating of the flat list used by communityList dataSource

src/app/home-page/top-level-community-list/top-level-community-list.component.ts

@@ -12,6 +12,7 @@ import { PaginationComponentOptions } from '../../shared/pagination/pagination-c
 import { hasValue } from '../../shared/empty.util';
 import { switchMap } from 'rxjs/operators';
 import { PaginationService } from '../../core/pagination/pagination.service';
+import { environment } from 'src/environments/environment';
 
 /**
  * this component renders the Top-Level Community list
@@ -54,7 +55,7 @@ export class TopLevelCommunityListComponent implements OnInit, OnDestroy {
               private paginationService: PaginationService) {
     this.config = new PaginationComponentOptions();
     this.config.id = this.pageId;
-    this.config.pageSize = 5;
+    this.config.pageSize = environment.browseCommunities.topLevelPageSize;
     this.config.currentPage = 1;
     this.sortConfig = new SortOptions('dc.title', SortDirection.ASC);
   }

src/config/app-config.interface.ts

@@ -31,6 +31,7 @@ interface AppConfig extends Config {
   defaultLanguage: string;
   languages: LangConfig[];
   browseBy: BrowseByConfig;
+  browseCommunities: BrowseCommunitiesConfig;
   item: ItemConfig;
   collection: CollectionPageConfig;
   themes: ThemeConfig[];

src/config/browse-communities-config.interface.ts

@@ -0,0 +1,12 @@
+import { Config } from './config.interface';
+
+export interface BrowseCommunitiesConfig extends Config {
+  /**
+   * Number of entries in the expandable community list (per show more).
+   */
+   communityListPageSize: number;
+  /**
+   * Number of entries in the paginated (home page) top level community list.
+   */
+   topLevelPageSize: number;
+}

src/config/default-app-config.ts

@@ -210,6 +210,11 @@ export class DefaultAppConfig implements AppConfig {
     defaultLowerLimit: 1900
   };
 
+  browseCommunities: BrowseCommunitiesConfig = {
+    communityListPageSize: 20,
+    topLevelPageSize: 5
+  }
+
   // Item Config
   item: ItemConfig = {
     edit: {

src/environments/environment.test.ts

@@ -204,6 +204,10 @@ export const environment: BuildConfig = {
     // The absolute lowest year to display in the dropdown (only used when no lowest date can be found for all items)
     defaultLowerLimit: 1900,
   },
+  browseCommunities: {
+    communityListPageSize: 20,
+    topLevelPageSize: 5
+  },
   item: {
     edit: {
       undoTimeout: 10000 // 10 seconds