Merge pull request #3907 from 4Science/task/dspace-7_x/DURACOM-303

[Port dspace-7_x] Exclude search and browse from Angular SSR

config/config.example.yml

@@ -25,6 +25,14 @@ ssr:
   inlineCriticalCss: false
   # Path prefixes to enable SSR for. By default these are limited to paths of primary DSpace objects.
   paths: [ '/home', '/items/', '/entities/', '/collections/', '/communities/', '/bitstream/', '/bitstreams/', '/handle/' ]
+  # Whether to enable rendering of Search component on SSR.
+  # If set to true the component will be included in the HTML returned from the server side rendering.
+  # If set to false the component will not be included in the HTML returned from the server side rendering.
+  enableSearchComponent: false,
+  # Whether to enable rendering of Browse component on SSR.
+  # If set to true the component will be included in the HTML returned from the server side rendering.
+  # If set to false the component will not be included in the HTML returned from the server side rendering.
+  enableBrowseComponent: false,
 
 # The REST API server settings
 # NOTE: these settings define which (publicly available) REST API to use. They are usually
@@ -412,3 +420,12 @@ liveRegion:
   messageTimeOutDurationMs: 30000
   # The visibility of the live region. Setting this to true is only useful for debugging purposes.
   isVisible: false
+
+
+# Search settings
+search:
+  # Number used to render n UI elements called loading skeletons that act as placeholders.
+  # These elements indicate that some content will be loaded in their stead.
+  # Since we don't know how many filters will be loaded before we receive a response from the server we use this parameter for the skeletons count.
+  # e.g. If we set 5 then 5 loading skeletons will be visualized before the actual filters are retrieved.
+  defaultFiltersCount: 5

package.json

@@ -111,6 +111,7 @@
     "ngx-infinite-scroll": "^15.0.0",
     "ngx-pagination": "6.0.3",
     "ngx-sortablejs": "^11.1.0",
+    "ngx-skeleton-loader": "^7.0.0",
     "ngx-ui-switch": "^14.1.0",
     "nouislider": "^15.8.1",
     "pem": "1.14.8",

src/app/browse-by/browse-by-date-page/browse-by-date-page.component.spec.ts

@@ -1,5 +1,5 @@
 import { BrowseByDatePageComponent } from './browse-by-date-page.component';
-import { ComponentFixture, TestBed, waitForAsync } from '@angular/core/testing';
+import { ComponentFixture, fakeAsync, TestBed, tick, waitForAsync } from '@angular/core/testing';
 import { CommonModule } from '@angular/common';
 import { RouterTestingModule } from '@angular/router/testing';
 import { TranslateModule } from '@ngx-translate/core';
@@ -9,7 +9,7 @@ import { ActivatedRoute, Router } from '@angular/router';
 import { BrowseService } from '../../core/browse/browse.service';
 import { DSpaceObjectDataService } from '../../core/data/dspace-object-data.service';
 import { RouterMock } from '../../shared/mocks/router.mock';
-import { ChangeDetectorRef, NO_ERRORS_SCHEMA } from '@angular/core';
+import { ChangeDetectorRef, NO_ERRORS_SCHEMA, PLATFORM_ID } from '@angular/core';
 import { of as observableOf } from 'rxjs';
 import { ActivatedRouteStub } from '../../shared/testing/active-router.stub';
 import { Community } from '../../core/shared/community.model';
@@ -24,6 +24,8 @@ import { APP_CONFIG } from '../../../config/app-config.interface';
 import { environment } from '../../../environments/environment';
 import { SortDirection } from '../../core/cache/models/sort-options.model';
 import { cold } from 'jasmine-marbles';
+import { Store } from '@ngrx/store';
+import { BrowseEntry } from '../../core/shared/browse-entry.model';
 
 describe('BrowseByDatePageComponent', () => {
   let comp: BrowseByDatePageComponent;
@@ -95,7 +97,10 @@ describe('BrowseByDatePageComponent', () => {
         { provide: Router, useValue: new RouterMock() },
         { provide: PaginationService, useValue: paginationService },
         { provide: ChangeDetectorRef, useValue: mockCdRef },
-        { provide: APP_CONFIG, useValue: environment }
+        { provide: APP_CONFIG, useValue: environment },
+        { provide: Store, useValue: {} },
+        { provide: APP_CONFIG, useValue: environment },
+        { provide: PLATFORM_ID, useValue: 'browser' },
       ],
       schemas: [NO_ERRORS_SCHEMA]
     }).compileComponents();
@@ -131,4 +136,33 @@ describe('BrowseByDatePageComponent', () => {
     //expect(comp.startsWithOptions[0]).toEqual(new Date().getUTCFullYear());
     expect(comp.startsWithOptions[0]).toEqual(1960);
   });
+
+  describe('when rendered in SSR', () => {
+    beforeEach(() => {
+      comp.platformId = 'server';
+      spyOn((comp as any).browseService, 'getBrowseItemsFor');
+    });
+
+    it('should not call getBrowseItemsFor on init', (done) => {
+      comp.ngOnInit();
+      expect((comp as any).browseService.getBrowseItemsFor).not.toHaveBeenCalled();
+      comp.loading$.subscribe((res) => {
+        expect(res).toBeFalsy();
+        done();
+      });
+    });
+  });
+
+  describe('when rendered in CSR', () => {
+    beforeEach(() => {
+      comp.platformId = 'browser';
+      spyOn((comp as any).browseService, 'getBrowseItemsFor').and.returnValue(createSuccessfulRemoteDataObject$(new BrowseEntry()));
+    });
+
+    it('should call getBrowseItemsFor on init', fakeAsync(() => {
+      comp.ngOnInit();
+      tick(100);
+      expect((comp as any).browseService.getBrowseItemsFor).toHaveBeenCalled();
+    }));
+  });
 });

src/app/browse-by/browse-by-date-page/browse-by-date-page.component.ts

@@ -1,4 +1,4 @@
-import { ChangeDetectorRef, Component, Inject } from '@angular/core';
+import { ChangeDetectorRef, Component, Inject, PLATFORM_ID } from '@angular/core';
 import {
   BrowseByMetadataPageComponent,
   browseParamsToOptions
@@ -11,6 +11,7 @@ import { DSpaceObjectDataService } from '../../core/data/dspace-object-data.serv
 import { StartsWithType } from '../../shared/starts-with/starts-with-decorator';
 import { PaginationService } from '../../core/pagination/pagination.service';
 import { map, take } from 'rxjs/operators';
+import { of as observableOf } from 'rxjs';
 import { PaginationComponentOptions } from '../../shared/pagination/pagination-component-options.model';
 import { SortDirection, SortOptions } from '../../core/cache/models/sort-options.model';
 import { isValidDate } from '../../shared/date.util';
@@ -18,6 +19,8 @@ import { APP_CONFIG, AppConfig } from '../../../config/app-config.interface';
 import { RemoteData } from '../../core/data/remote-data';
 import { Item } from '../../core/shared/item.model';
 import { DSONameService } from '../../core/breadcrumbs/dso-name.service';
+import { isPlatformServer } from '@angular/common';
+import { environment } from '../../../environments/environment';
 
 @Component({
   selector: 'ds-browse-by-date-page',
@@ -44,11 +47,16 @@ export class BrowseByDatePageComponent extends BrowseByMetadataPageComponent {
                      protected cdRef: ChangeDetectorRef,
                      @Inject(APP_CONFIG) public appConfig: AppConfig,
                      public dsoNameService: DSONameService,
+                     @Inject(PLATFORM_ID) public platformId: any,
   ) {
-    super(route, browseService, dsoService, paginationService, router, appConfig, dsoNameService);
+    super(route, browseService, dsoService, paginationService, router, appConfig, dsoNameService, platformId);
   }
 
   ngOnInit(): void {
+    if (!this.renderOnServerSide && !environment.universal.enableBrowseComponent && isPlatformServer(this.platformId)) {
+      this.loading$ = observableOf(false);
+      return;
+    }
     const sortConfig = new SortOptions('default', SortDirection.ASC);
     this.startsWithType = StartsWithType.date;
     this.currentPagination$ = this.paginationService.getCurrentPagination(this.paginationConfig.id, this.paginationConfig);

src/app/browse-by/browse-by-metadata-page/browse-by-metadata-page.component.html

@@ -1,4 +1,4 @@
-<div class="container">
+<div class="container" *ngIf="(!ssrRenderingDisabled)">
     <ng-container *ngVar="(parent$ | async) as parent">
     <ng-container *ngIf="parent?.payload as parentContext">
         <div class="d-flex flex-row border-bottom mb-4 pb-4">

src/app/browse-by/browse-by-metadata-page/browse-by-metadata-page.component.spec.ts

@@ -3,7 +3,7 @@ import {
   browseParamsToOptions,
   getBrowseSearchOptions
 } from './browse-by-metadata-page.component';
-import { ComponentFixture, TestBed, waitForAsync } from '@angular/core/testing';
+import { ComponentFixture, fakeAsync, TestBed, tick, waitForAsync } from '@angular/core/testing';
 import { BrowseService } from '../../core/browse/browse.service';
 import { CommonModule } from '@angular/common';
 import { RouterTestingModule } from '@angular/router/testing';
@@ -13,7 +13,7 @@ import { EnumKeysPipe } from '../../shared/utils/enum-keys-pipe';
 import { ActivatedRoute, Router } from '@angular/router';
 import { ActivatedRouteStub } from '../../shared/testing/active-router.stub';
 import { Observable, of as observableOf } from 'rxjs';
-import { NO_ERRORS_SCHEMA } from '@angular/core';
+import { NO_ERRORS_SCHEMA, PLATFORM_ID } from '@angular/core';
 import { RemoteData } from '../../core/data/remote-data';
 import { buildPaginatedList, PaginatedList } from '../../core/data/paginated-list.model';
 import { PageInfo } from '../../core/shared/page-info.model';
@@ -111,7 +111,8 @@ describe('BrowseByMetadataPageComponent', () => {
         { provide: DSpaceObjectDataService, useValue: mockDsoService },
         { provide: PaginationService, useValue: paginationService },
         { provide: Router, useValue: new RouterMock() },
-        { provide: APP_CONFIG, useValue: environmentMock }
+        { provide: APP_CONFIG, useValue: environmentMock },
+        { provide: PLATFORM_ID, useValue: 'browser' },
       ],
       schemas: [NO_ERRORS_SCHEMA]
     }).compileComponents();
@@ -224,6 +225,35 @@ describe('BrowseByMetadataPageComponent', () => {
       expect(result.fetchThumbnail).toBeTrue();
     });
   });
+
+  describe('when rendered in SSR', () => {
+    beforeEach(() => {
+      comp.ssrRenderingDisabled = true;
+      spyOn((comp as any).browseService, 'getBrowseEntriesFor').and.returnValue(createSuccessfulRemoteDataObject$(null));
+    });
+
+    it('should not call getBrowseEntriesFor on init', (done) => {
+      comp.ngOnInit();
+      expect((comp as any).browseService.getBrowseEntriesFor).not.toHaveBeenCalled();
+      comp.loading$.subscribe((res) => {
+        expect(res).toBeFalsy();
+        done();
+      });
+    });
+  });
+
+  describe('when rendered in CSR', () => {
+    beforeEach(() => {
+      comp.ssrRenderingDisabled = false;
+      spyOn((comp as any).browseService, 'getBrowseEntriesFor').and.returnValue(createSuccessfulRemoteDataObject$(new BrowseEntry()));
+    });
+
+    it('should call getBrowseEntriesFor on init', fakeAsync(() => {
+      comp.ngOnInit();
+      tick(100);
+      expect((comp as any).browseService.getBrowseEntriesFor).toHaveBeenCalled();
+    }));
+  });
 });
 
 export function toRemoteData(objects: any[]): Observable<RemoteData<PaginatedList<any>>> {

src/app/browse-by/browse-by-metadata-page/browse-by-metadata-page.component.ts

@@ -1,5 +1,5 @@
 import { combineLatest as observableCombineLatest, Observable, Subscription, of as observableOf } from 'rxjs';
-import { Component, Inject, OnInit, OnDestroy } from '@angular/core';
+import { Component, Inject, OnInit, OnDestroy, Input, PLATFORM_ID } from '@angular/core';
 import { RemoteData } from '../../core/data/remote-data';
 import { PaginatedList } from '../../core/data/paginated-list.model';
 import { PaginationComponentOptions } from '../../shared/pagination/pagination-component-options.model';
@@ -22,6 +22,8 @@ import { Collection } from '../../core/shared/collection.model';
 import { Community } from '../../core/shared/community.model';
 import { APP_CONFIG, AppConfig } from '../../../config/app-config.interface';
 import { DSONameService } from '../../core/breadcrumbs/dso-name.service';
+import { isPlatformServer } from '@angular/common';
+import { environment } from '../../../environments/environment';
 
 export const BBM_PAGINATION_ID = 'bbm';
 
@@ -37,7 +39,10 @@ export const BBM_PAGINATION_ID = 'bbm';
  * 'dc.contributor.*'
  */
 export class BrowseByMetadataPageComponent implements OnInit, OnDestroy {
-
+  /**
+   * Defines whether to fetch search results during SSR execution
+   */
+  @Input() renderOnServerSide = false;
   /**
    * The list of browse-entries to display
    */
@@ -126,6 +131,10 @@ export class BrowseByMetadataPageComponent implements OnInit, OnDestroy {
    * Observable determining if the loading animation needs to be shown
    */
   loading$ = observableOf(true);
+  /**
+   * Whether this component should be rendered or not in SSR
+   */
+  ssrRenderingDisabled = false;
 
   public constructor(protected route: ActivatedRoute,
                      protected browseService: BrowseService,
@@ -134,6 +143,7 @@ export class BrowseByMetadataPageComponent implements OnInit, OnDestroy {
                      protected router: Router,
                      @Inject(APP_CONFIG) public appConfig: AppConfig,
                      public dsoNameService: DSONameService,
+                     @Inject(PLATFORM_ID) public platformId: any,
   ) {
 
     this.fetchThumbnails = this.appConfig.browseBy.showThumbnails;
@@ -142,11 +152,15 @@ export class BrowseByMetadataPageComponent implements OnInit, OnDestroy {
         currentPage: 1,
         pageSize: this.appConfig.browseBy.pageSize,
         });
-    }
+    this.ssrRenderingDisabled = !this.renderOnServerSide && !environment.universal.enableBrowseComponent && isPlatformServer(this.platformId);
+  }
 
 
   ngOnInit(): void {
-
+    if (this.ssrRenderingDisabled) {
+      this.loading$ = observableOf(false);
+      return;
+    }
     const sortConfig = new SortOptions('default', SortDirection.ASC);
     this.updatePage(getBrowseSearchOptions(this.defaultBrowseId, this.paginationConfig, sortConfig));
     this.currentPagination$ = this.paginationService.getCurrentPagination(this.paginationConfig.id, this.paginationConfig);

src/app/browse-by/browse-by-title-page/browse-by-title-page.component.spec.ts

@@ -1,4 +1,4 @@
-import { ComponentFixture, TestBed, waitForAsync } from '@angular/core/testing';
+import { ComponentFixture, fakeAsync, TestBed, tick, waitForAsync } from '@angular/core/testing';
 import { ActivatedRoute, Router } from '@angular/router';
 import { Item } from '../../core/shared/item.model';
 import { ActivatedRouteStub } from '../../shared/testing/active-router.stub';
@@ -22,6 +22,7 @@ import { PaginationService } from '../../core/pagination/pagination.service';
 import { PaginationServiceStub } from '../../shared/testing/pagination-service.stub';
 import { APP_CONFIG } from '../../../config/app-config.interface';
 import { environment } from '../../../environments/environment';
+import { BrowseEntry } from '../../core/shared/browse-entry.model';
 
 
 describe('BrowseByTitlePageComponent', () => {
@@ -63,7 +64,8 @@ describe('BrowseByTitlePageComponent', () => {
 
   const activatedRouteStub = Object.assign(new ActivatedRouteStub(), {
     params: observableOf({}),
-    data: observableOf({ metadata: 'title' })
+    queryParams: observableOf({}),
+    data: observableOf({ metadata: 'title' }),
   });
 
   const paginationService = new PaginationServiceStub();
@@ -97,4 +99,35 @@ describe('BrowseByTitlePageComponent', () => {
       expect(result.payload.page).toEqual(mockItems);
     });
   });
+
+  describe('when rendered in SSR', () => {
+    beforeEach(() => {
+      comp.platformId = 'server';
+      spyOn((comp as any).browseService, 'getBrowseItemsFor');
+      fixture.detectChanges();
+    });
+
+    it('should not call getBrowseItemsFor on init', (done) => {
+      comp.ngOnInit();
+      expect((comp as any).browseService.getBrowseItemsFor).not.toHaveBeenCalled();
+      comp.loading$.subscribe((res) => {
+        expect(res).toBeFalsy();
+        done();
+      });
+    });
+  });
+
+  describe('when rendered in CSR', () => {
+    beforeEach(() => {
+      comp.platformId = 'browser';
+      fixture.detectChanges();
+      spyOn((comp as any).browseService, 'getBrowseItemsFor').and.returnValue(createSuccessfulRemoteDataObject$(new BrowseEntry()));
+    });
+
+    it('should call getBrowseItemsFor on init', fakeAsync(() => {
+      comp.ngOnInit();
+      tick(100);
+      expect((comp as any).browseService.getBrowseItemsFor).toHaveBeenCalled();
+    }));
+  });
 });

src/app/browse-by/browse-by-title-page/browse-by-title-page.component.ts

@@ -1,5 +1,5 @@
 import { combineLatest as observableCombineLatest } from 'rxjs';
-import { Component, Inject } from '@angular/core';
+import { Component, Inject, PLATFORM_ID } from '@angular/core';
 import { ActivatedRoute, Params, Router } from '@angular/router';
 import { hasValue } from '../../shared/empty.util';
 import {
@@ -11,9 +11,12 @@ import { BrowseService } from '../../core/browse/browse.service';
 import { SortDirection, SortOptions } from '../../core/cache/models/sort-options.model';
 import { PaginationService } from '../../core/pagination/pagination.service';
 import { map, take } from 'rxjs/operators';
+import { of as observableOf } from 'rxjs';
 import { PaginationComponentOptions } from '../../shared/pagination/pagination-component-options.model';
 import { AppConfig, APP_CONFIG } from '../../../config/app-config.interface';
 import { DSONameService } from '../../core/breadcrumbs/dso-name.service';
+import { isPlatformServer } from '@angular/common';
+import { environment } from '../../../environments/environment';
 
 @Component({
   selector: 'ds-browse-by-title-page',
@@ -32,11 +35,16 @@ export class BrowseByTitlePageComponent extends BrowseByMetadataPageComponent {
                      protected router: Router,
                      @Inject(APP_CONFIG) public appConfig: AppConfig,
                      public dsoNameService: DSONameService,
+                     @Inject(PLATFORM_ID) public platformId: any,
   ) {
-    super(route, browseService, dsoService, paginationService, router, appConfig, dsoNameService);
+    super(route, browseService, dsoService, paginationService, router, appConfig, dsoNameService, platformId);
   }
 
   ngOnInit(): void {
+    if (!this.renderOnServerSide && !environment.universal.enableBrowseComponent && isPlatformServer(this.platformId)) {
+      this.loading$ = observableOf(false);
+      return;
+    }
     const sortConfig = new SortOptions('dc.title', SortDirection.ASC);
     this.currentPagination$ = this.paginationService.getCurrentPagination(this.paginationConfig.id, this.paginationConfig);
     this.currentSort$ = this.paginationService.getCurrentSort(this.paginationConfig.id, sortConfig);

src/app/search-page/configuration-search-page.component.ts

@@ -1,7 +1,7 @@
 import { HostWindowService } from '../shared/host-window.service';
 import { SidebarService } from '../shared/sidebar/sidebar.service';
 import { SearchComponent } from '../shared/search/search.component';
-import { ChangeDetectionStrategy, Component, Inject } from '@angular/core';
+import { ChangeDetectionStrategy, Component, Inject, PLATFORM_ID } from '@angular/core';
 import { pushInOut } from '../shared/animations/push';
 import { SEARCH_CONFIG_SERVICE } from '../my-dspace-page/my-dspace-page.component';
 import { SearchConfigurationService } from '../core/shared/search/search-configuration.service';
@@ -35,7 +35,8 @@ export class ConfigurationSearchPageComponent extends SearchComponent {
               protected routeService: RouteService,
               protected router: Router,
               @Inject(APP_CONFIG) protected appConfig: AppConfig,
+              @Inject(PLATFORM_ID) public platformId: any,
   ) {
-    super(service, sidebarService, windowService, searchConfigService, routeService, router, appConfig);
+    super(service, sidebarService, windowService, searchConfigService, routeService, router, appConfig, platformId);
   }
 }

src/app/shared/search/search-filters/search-filter/search-filter.component.ts

@@ -1,4 +1,4 @@
-import { Component, Inject, Input, OnInit } from '@angular/core';
+import { Component, EventEmitter, Inject, Input, OnInit, Output } from '@angular/core';
 
 import { BehaviorSubject, Observable, of as observableOf } from 'rxjs';
 import { filter, map, startWith, switchMap, take } from 'rxjs/operators';
@@ -43,6 +43,8 @@ export class SearchFilterComponent implements OnInit {
    */
   @Input() scope: string;
 
+  @Output() isVisibilityComputed = new EventEmitter<boolean>();
+
   /**
    * True when the filter is 100% collapsed in the UI
    */
@@ -91,7 +93,9 @@ export class SearchFilterComponent implements OnInit {
    */
   ngOnInit() {
     this.selectedValues$ = this.getSelectedValues();
-    this.active$ = this.isActive();
+    this.active$ = this.isActive().pipe(
+      startWith(true)
+    );
     this.collapsed$ = this.isCollapsed();
     this.initializeFilter();
     this.selectedValues$.pipe(take(1)).subscribe((selectedValues) => {
@@ -99,6 +103,9 @@ export class SearchFilterComponent implements OnInit {
         this.filterService.expand(this.filter.name);
       }
     });
+    this.isActive().pipe(take(1)).subscribe(() => {
+      this.isVisibilityComputed.emit(true);
+    });
   }
 
   /**
@@ -187,7 +194,7 @@ export class SearchFilterComponent implements OnInit {
               }
             ));
         }
-      }),
-      startWith(true));
+      })
+    );
   }
 }

src/app/shared/search/search-filters/search-filters.component.html

@@ -1,7 +1,13 @@
 <h3>{{"search.filters.head" | translate}}</h3>
 <div *ngIf="(filters | async)?.hasSucceeded">
-    <div *ngFor="let filter of (filters | async)?.payload; trackBy: trackUpdate">
-        <ds-search-filter [scope]="currentScope" [filter]="filter" [inPlaceSearch]="inPlaceSearch" [refreshFilters]="refreshFilters"></ds-search-filter>
+    <div [class.visually-hidden]="filtersWithComputedVisibility !== (filters | async)?.payload?.length"
+         *ngFor="let filter of (filters | async)?.payload; trackBy: trackUpdate">
+        <ds-search-filter (isVisibilityComputed)="countFiltersWithComputedVisibility($event)" [scope]="currentScope" [filter]="filter" [inPlaceSearch]="inPlaceSearch" [refreshFilters]="refreshFilters"></ds-search-filter>
     </div>
 </div>
+
+
+<ng-container *ngIf="filtersWithComputedVisibility !== (filters | async)?.payload?.length">
+  <ngx-skeleton-loader [count]="defaultFilterCount"/>
+</ng-container>
 <a class="btn btn-primary" [routerLink]="[searchLink]" [queryParams]="clearParams | async" queryParamsHandling="merge" role="button"><i class="fas fa-undo"></i> {{"search.filters.reset" | translate}}</a>

src/app/shared/search/search-filters/search-filters.component.scss

@@ -1,2 +1,12 @@
 @import '../../../../styles/variables';
 @import '../../../../styles/mixins';
+
+:host ::ng-deep {
+  ngx-skeleton-loader .skeleton-loader {
+    height: var(--ds-filters-skeleton-height);
+    margin-bottom: var(--ds-filters-skeleton-spacing);
+    padding: var(--ds-filters-skeleton-spacing);
+    background-color: var(--bs-light);
+    box-shadow: none;
+  }
+}

src/app/shared/search/search-filters/search-filters.component.spec.ts

@@ -9,6 +9,8 @@ import { SearchFiltersComponent } from './search-filters.component';
 import { SearchService } from '../../../core/shared/search/search.service';
 import { SEARCH_CONFIG_SERVICE } from '../../../my-dspace-page/my-dspace-page.component';
 import { SearchConfigurationServiceStub } from '../../testing/search-configuration-service.stub';
+import { APP_CONFIG } from '../../../../config/app-config.interface';
+import { environment } from '../../../../environments/environment';
 
 describe('SearchFiltersComponent', () => {
   let comp: SearchFiltersComponent;
@@ -37,7 +39,7 @@ describe('SearchFiltersComponent', () => {
         { provide: SearchService, useValue: searchServiceStub },
         { provide: SEARCH_CONFIG_SERVICE, useValue: new SearchConfigurationServiceStub() },
         { provide: SearchFilterService, useValue: searchFiltersStub },
-
+        { provide: APP_CONFIG, useValue: environment },
       ],
       schemas: [NO_ERRORS_SCHEMA]
     }).overrideComponent(SearchFiltersComponent, {

src/app/shared/search/search-filters/search-filters.component.ts

@@ -2,7 +2,7 @@ import { Component, Inject, Input, OnDestroy, OnInit } from '@angular/core';
 import { Router } from '@angular/router';
 
 import { BehaviorSubject, Observable } from 'rxjs';
-import { map } from 'rxjs/operators';
+import { map, tap } from 'rxjs/operators';
 
 import { SearchService } from '../../../core/shared/search/search.service';
 import { RemoteData } from '../../../core/data/remote-data';
@@ -12,6 +12,7 @@ import { SearchFilterService } from '../../../core/shared/search/search-filter.s
 import { SEARCH_CONFIG_SERVICE } from '../../../my-dspace-page/my-dspace-page.component';
 import { currentPath } from '../../utils/route.utils';
 import { hasValue } from '../../empty.util';
+import { APP_CONFIG, AppConfig } from '../../../../config/app-config.interface';
 
 @Component({
   selector: 'ds-search-filters',
@@ -60,7 +61,13 @@ export class SearchFiltersComponent implements OnInit, OnDestroy {
    */
   searchLink: string;
 
+  /**
+   * Filters for which visibility has been computed
+   */
+  filtersWithComputedVisibility = 0;
+
   subs = [];
+  defaultFilterCount: number;
 
   /**
    * Initialize instance variables
@@ -68,19 +75,26 @@ export class SearchFiltersComponent implements OnInit, OnDestroy {
    * @param {SearchFilterService} filterService
    * @param {Router} router
    * @param {SearchConfigurationService} searchConfigService
+   * @param appConfig
    */
   constructor(
     private searchService: SearchService,
     private filterService: SearchFilterService,
     private router: Router,
-    @Inject(SEARCH_CONFIG_SERVICE) private searchConfigService: SearchConfigurationService) {
+    @Inject(SEARCH_CONFIG_SERVICE) private searchConfigService: SearchConfigurationService,
+    @Inject(APP_CONFIG) protected appConfig: AppConfig,
+  ) {
+    this.defaultFilterCount = this.appConfig.search.filterPlaceholdersCount ?? 5;
   }
 
   ngOnInit(): void {
-    this.clearParams = this.searchConfigService.getCurrentFrontendFilters().pipe(map((filters) => {
-      Object.keys(filters).forEach((f) => filters[f] = null);
-      return filters;
-    }));
+    this.clearParams = this.searchConfigService.getCurrentFrontendFilters().pipe(
+      tap(() => this.filtersWithComputedVisibility = 0),
+      map((filters) => {
+        Object.keys(filters).forEach((f) => filters[f] = null);
+        return filters;
+      })
+    );
     this.searchLink = this.getSearchLink();
   }
 
@@ -108,4 +122,10 @@ export class SearchFiltersComponent implements OnInit, OnDestroy {
       }
     });
   }
+
+  countFiltersWithComputedVisibility(computed: boolean) {
+    if (computed) {
+      this.filtersWithComputedVisibility += 1;
+    }
+  }
 }

src/app/shared/search/search-results/search-results-skeleton/search-results-skeleton.component.html

@@ -0,0 +1,38 @@
+<div class="row flex-nowrap">
+  <div [class.mb-2]="(viewMode$ | async) === ViewMode.ListElement" class="info-skeleton col-12">
+    <ngx-skeleton-loader/>
+  </div>
+</div>
+
+<ng-container *ngIf="(viewMode$ | async) === ViewMode.ListElement; else grid">
+  <ng-container *ngFor="let result of loadingResults; let first = first">
+    <div [class.my-4]="!first" class="row">
+      <div *ngIf="showThumbnails" class="col-3 col-md-2">
+        <div class="thumbnail-skeleton position-relative">
+          <ngx-skeleton-loader/>
+        </div>
+      </div>
+      <div [class.col-9]="showThumbnails" [class.col-md-10]="showThumbnails" [class.col-md-12]="!showThumbnails">
+        <div class="badge-skeleton">
+          <ngx-skeleton-loader/>
+        </div>
+        <div class="text-skeleton">
+          <ngx-skeleton-loader [count]="textLineCount"/>
+        </div>
+      </div>
+    </div>
+  </ng-container>
+</ng-container>
+
+<ng-template #grid>
+  <div class="card-columns row">
+    <ng-container *ngFor="let result of loadingResults">
+      <div class="card-column col col-sm-6 col-lg-4">
+        <div class="card-skeleton">
+          <ngx-skeleton-loader/>
+        </div>
+      </div>
+    </ng-container>
+  </div>
+</ng-template>
+

src/app/shared/search/search-results/search-results-skeleton/search-results-skeleton.component.scss

@@ -0,0 +1,56 @@
+:host ::ng-deep {
+  --ds-wrapper-grid-spacing: calc(var(--bs-spacer) / 2);
+
+  .info-skeleton, .badge-skeleton, .text-skeleton{
+    ngx-skeleton-loader .skeleton-loader {
+      height: var(--ds-search-skeleton-text-height);
+    }
+  }
+
+  .badge-skeleton, .info-skeleton {
+    ngx-skeleton-loader .skeleton-loader {
+      width: var(--ds-search-skeleton-badge-width);
+    }
+  }
+
+  .info-skeleton {
+    ngx-skeleton-loader .skeleton-loader {
+      width: var(--ds-search-skeleton-info-width);
+    }
+  }
+
+  .thumbnail-skeleton {
+    max-width: var(--ds-thumbnail-max-width);
+    height: 100%;
+
+    ngx-skeleton-loader .skeleton-loader {
+      margin-right: var(--ds-search-skeleton-thumbnail-margin);
+      border-radius: 0;
+      height: 100%;
+    }
+  }
+
+  .card-skeleton {
+    ngx-skeleton-loader .skeleton-loader {
+      height: var(--ds-search-skeleton-card-height);
+    }
+  }
+
+  ngx-skeleton-loader .skeleton-loader {
+    background-color: var(--bs-light);
+    box-shadow: none;
+  }
+
+  .card-columns {
+    margin-left: calc(-1 * var(--ds-wrapper-grid-spacing));
+    margin-right: calc(-1 * var(--ds-wrapper-grid-spacing));
+    column-gap: 0;
+
+    .card-column {
+      padding-left: var(--ds-wrapper-grid-spacing);
+      padding-right: var(--ds-wrapper-grid-spacing);
+    }
+  }
+}
+
+

src/app/shared/search/search-results/search-results-skeleton/search-results-skeleton.component.spec.ts

@@ -0,0 +1,33 @@
+import {
+  ComponentFixture,
+  TestBed,
+} from '@angular/core/testing';
+import { NgxSkeletonLoaderModule } from 'ngx-skeleton-loader';
+
+import { SearchService } from '../../../../core/shared/search/search.service';
+import { SearchServiceStub } from '../../../testing/search-service.stub';
+import { SearchResultsSkeletonComponent } from './search-results-skeleton.component';
+
+describe('SearchResultsSkeletonComponent', () => {
+  let component: SearchResultsSkeletonComponent;
+  let fixture: ComponentFixture<SearchResultsSkeletonComponent>;
+
+  beforeEach(async () => {
+    await TestBed.configureTestingModule({
+      imports: [NgxSkeletonLoaderModule],
+      declarations: [SearchResultsSkeletonComponent],
+      providers: [
+        { provide: SearchService, useValue: new SearchServiceStub() },
+      ],
+    })
+      .compileComponents();
+
+    fixture = TestBed.createComponent(SearchResultsSkeletonComponent);
+    component = fixture.componentInstance;
+    fixture.detectChanges();
+  });
+
+  it('should create', () => {
+    expect(component).toBeTruthy();
+  });
+});

src/app/shared/search/search-results/search-results-skeleton/search-results-skeleton.component.ts

@@ -0,0 +1,59 @@
+import {
+  Component,
+  Input,
+  OnInit,
+} from '@angular/core';
+import { Observable } from 'rxjs';
+
+import { SearchService } from '../../../../core/shared/search/search.service';
+import { ViewMode } from '../../../../core/shared/view-mode.model';
+import { hasValue } from '../../../empty.util';
+
+@Component({
+  selector: 'ds-search-results-skeleton',
+  templateUrl: './search-results-skeleton.component.html',
+  styleUrls: ['./search-results-skeleton.component.scss'],
+})
+/**
+ * Component to show placeholders for search results while loading, to give a loading feedback to the user without layout shifting.
+ */
+export class SearchResultsSkeletonComponent implements OnInit {
+  /**
+   * Whether the search result contains thumbnail
+   */
+  @Input()
+  showThumbnails: boolean;
+  /**
+   * The number of search result loaded in the current page
+   */
+  @Input()
+  numberOfResults = 0;
+  /**
+   * How many placeholder are displayed for the search result text
+   */
+  @Input()
+  textLineCount = 2;
+  /**
+   * The view mode of the search page
+   */
+  public viewMode$: Observable<ViewMode>;
+  /**
+   * Array built from numberOfResults to count and iterate based on index
+   */
+  public loadingResults: number[];
+
+  protected readonly ViewMode = ViewMode;
+
+  constructor(private searchService: SearchService) {
+    this.viewMode$ = this.searchService.getViewMode();
+  }
+
+  ngOnInit() {
+    this.loadingResults = Array.from({ length: this.numberOfResults }, (_, i) => i + 1);
+
+    if (!hasValue(this.showThumbnails)) {
+      // this is needed as the default value of show thumbnails is true but set in lower levels of the DOM.
+      this.showThumbnails = true;
+    }
+  }
+}

src/app/shared/search/search-results/search-results.component.html

@@ -19,7 +19,13 @@
             (selectObject)="selectObject.emit($event)">
     </ds-viewable-collection>
 </div>
-<ds-themed-loading *ngIf="isLoading()" message="{{'loading.search-results' | translate}}"></ds-themed-loading>
+
+<ds-search-results-skeleton
+  *ngIf="isLoading()"
+  [showThumbnails]="showThumbnails"
+  [numberOfResults]="searchConfig.pagination.pageSize"
+></ds-search-results-skeleton>
+
 <ds-error *ngIf="showError()"
           message="{{errorMessageLabel() | translate}}"></ds-error>
 <div *ngIf="searchResults?.payload?.page.length == 0 || searchResults?.statusCode == 400">

src/app/shared/search/search-results/search-results.component.scss

@@ -0,0 +1,17 @@
+:host ::ng-deep {
+  .filter-badge-skeleton {
+    ngx-skeleton-loader .skeleton-loader {
+      background-color: var(--bs-light);
+      box-shadow: none;
+      width: var(--ds-search-skeleton-filter-badge-width);
+      height: var(--ds-search-skeleton-badge-height);
+      margin-bottom: 0;
+      margin-right: calc(var(--bs-spacer) / 4);
+    }
+  }
+
+  .filters-badge-skeleton-container {
+    display: flex;
+    max-height: var(--ds-search-skeleton-badge-height);
+  }
+}

src/app/shared/search/search-results/search-results.component.spec.ts

@@ -7,6 +7,11 @@ import { TranslateModule } from '@ngx-translate/core';
 import { SearchResultsComponent } from './search-results.component';
 import { QueryParamsDirectiveStub } from '../../testing/query-params-directive.stub';
 import { createFailedRemoteDataObject } from '../../remote-data.utils';
+import { SearchResultsSkeletonComponent } from './search-results-skeleton/search-results-skeleton.component';
+import { SearchConfigurationService } from '../../../core/shared/search/search-configuration.service';
+import { SearchConfigurationServiceStub } from '../../testing/search-configuration-service.stub';
+import { SearchService } from '../../../core/shared/search/search.service';
+import { SearchServiceStub } from '../../testing/search-service.stub';
 
 describe('SearchResultsComponent', () => {
   let comp: SearchResultsComponent;
@@ -19,7 +24,13 @@ describe('SearchResultsComponent', () => {
       imports: [TranslateModule.forRoot(), NoopAnimationsModule],
       declarations: [
         SearchResultsComponent,
-        QueryParamsDirectiveStub],
+        SearchResultsSkeletonComponent,
+        QueryParamsDirectiveStub
+      ],
+      providers: [
+        { provide: SearchConfigurationService, useValue: new SearchConfigurationServiceStub() },
+        { provide: SearchService, useValue: new SearchServiceStub() },
+      ],
       schemas: [NO_ERRORS_SCHEMA]
     }).compileComponents();
   }));
@@ -63,7 +74,7 @@ describe('SearchResultsComponent', () => {
 
   it('should display link with new search where query is quoted if search return a error 400', () => {
     (comp as any).searchResults = createFailedRemoteDataObject('Error', 400);
-    (comp as any).searchConfig = { query: 'foobar' };
+    (comp as any).searchConfig = { query: 'foobar', pagination: { pageSize: 10 } };
     fixture.detectChanges();
 
     const linkDes = fixture.debugElement.queryAll(By.directive(QueryParamsDirectiveStub));

src/app/shared/search/search-results/search-results.component.ts

@@ -11,6 +11,10 @@ import { CollectionElementLinkType } from '../../object-collection/collection-el
 import { ViewMode } from '../../../core/shared/view-mode.model';
 import { Context } from '../../../core/shared/context.model';
 import { PaginatedSearchOptions } from '../models/paginated-search-options.model';
+import { SearchFilter } from '../models/search-filter.model';
+import { Observable } from 'rxjs';
+import { SearchConfigurationService } from '../../../core/shared/search/search-configuration.service';
+import { SearchService } from '../../../core/shared/search/search.service';
 
 export interface SelectionConfig {
   repeatable: boolean;
@@ -19,6 +23,7 @@ export interface SelectionConfig {
 
 @Component({
   selector: 'ds-search-results',
+  styleUrls: ['./search-results.component.scss'],
   templateUrl: './search-results.component.html',
   animations: [
     fadeIn,
@@ -32,6 +37,8 @@ export interface SelectionConfig {
 export class SearchResultsComponent {
   hasNoValue = hasNoValue;
 
+  filters$: Observable<SearchFilter[]>;
+
   /**
    * The link type of the listed search results
    */
@@ -104,6 +111,13 @@ export class SearchResultsComponent {
 
   @Output() selectObject: EventEmitter<ListableObject> = new EventEmitter<ListableObject>();
 
+  constructor(
+    protected searchConfigService: SearchConfigurationService,
+    protected searchService: SearchService,
+  ) {
+    this.filters$ = this.searchConfigService.getCurrentFilters();
+  }
+
   /**
    * Check if search results are loading
    */

src/app/shared/search/search.component.spec.ts

@@ -1,4 +1,4 @@
-import { ChangeDetectionStrategy, NO_ERRORS_SCHEMA } from '@angular/core';
+import { ChangeDetectionStrategy, NO_ERRORS_SCHEMA, PLATFORM_ID } from '@angular/core';
 
 import { ComponentFixture, fakeAsync, TestBed, tick, waitForAsync } from '@angular/core/testing';
 import { RouterTestingModule } from '@angular/router/testing';
@@ -216,6 +216,7 @@ export function configureSearchComponentTestingModule(compType, additionalDeclar
         useValue: searchConfigurationServiceStub
       },
       { provide: APP_CONFIG, useValue: environment },
+      { provide: PLATFORM_ID, useValue: 'browser' },
     ],
     schemas: [NO_ERRORS_SCHEMA]
   }).overrideComponent(compType, {
@@ -374,5 +375,34 @@ describe('SearchComponent', () => {
         expect(result).toBeNull();
       });
     });
+
+    describe('when rendered in SSR', () => {
+      beforeEach(() => {
+        comp.platformId = 'server';
+      });
+
+      it('should not call search method on init', (done) => {
+        comp.ngOnInit();
+        //Check that the first method from which the search depend upon is not being called
+        expect(searchConfigurationServiceStub.getCurrentConfiguration).not.toHaveBeenCalled();
+        comp.initialized$.subscribe((res) => {
+          expect(res).toBeTruthy();
+          done();
+        });
+      });
+    });
+
+    describe('when rendered in CSR', () => {
+      beforeEach(() => {
+        comp.platformId = 'browser';
+      });
+
+      it('should call search method on init', fakeAsync(() => {
+        comp.ngOnInit();
+        tick(100);
+        //Check that the last method from which the search depend upon is being called
+        expect(searchServiceStub.search).toHaveBeenCalled();
+      }));
+    });
   });
 });

src/app/shared/search/search.component.ts

@@ -1,4 +1,14 @@
-import { ChangeDetectionStrategy, Component, EventEmitter, Inject, Input, OnInit, Output, OnDestroy } from '@angular/core';
+import {
+  ChangeDetectionStrategy,
+  Component,
+  EventEmitter,
+  Inject,
+  Input,
+  OnInit,
+  Output,
+  OnDestroy,
+  PLATFORM_ID
+} from '@angular/core';
 import { NavigationStart, Router } from '@angular/router';
 
 import { BehaviorSubject, combineLatest, Observable, Subscription } from 'rxjs';
@@ -38,6 +48,8 @@ import { ITEM_MODULE_PATH } from '../../item-page/item-page-routing-paths';
 import { COLLECTION_MODULE_PATH } from '../../collection-page/collection-page-routing-paths';
 import { COMMUNITY_MODULE_PATH } from '../../community-page/community-page-routing-paths';
 import { AppConfig, APP_CONFIG } from '../../../config/app-config.interface';
+import { isPlatformServer } from '@angular/common';
+import { environment } from 'src/environments/environment';
 
 @Component({
   selector: 'ds-search',
@@ -176,6 +188,11 @@ export class SearchComponent implements OnDestroy, OnInit {
    */
   @Input() scope: string;
 
+  /**
+   * Defines whether to fetch search results during SSR execution
+   */
+  @Input() renderOnServerSide = false;
+
   /**
    * The current configuration used during the search
    */
@@ -285,6 +302,7 @@ export class SearchComponent implements OnDestroy, OnInit {
               protected routeService: RouteService,
               protected router: Router,
               @Inject(APP_CONFIG) protected appConfig: AppConfig,
+              @Inject(PLATFORM_ID) public platformId: any,
   ) {
     this.isXsOrSm$ = this.windowService.isXsOrSm();
   }
@@ -297,6 +315,14 @@ export class SearchComponent implements OnDestroy, OnInit {
    * If something changes, update the list of scopes for the dropdown
    */
   ngOnInit(): void {
+    if (!this.renderOnServerSide && !environment.universal.enableSearchComponent && isPlatformServer(this.platformId)) {
+      this.subs.push(this.getSearchOptions().pipe(distinctUntilChanged()).subscribe((options) => {
+        this.searchOptions$.next(options);
+      }));
+      this.initialized$.next(true);
+      return;
+    }
+
     if (this.useUniquePageId) {
       // Create an unique pagination id related to the instance of the SearchComponent
       this.paginationId = uniqueId(this.paginationId);

src/app/shared/search/search.module.ts

@@ -34,6 +34,10 @@ import { ThemedSearchSettingsComponent } from './search-settings/themed-search-s
 import { NouisliderModule } from 'ng2-nouislider';
 import { ThemedSearchFiltersComponent } from './search-filters/themed-search-filters.component';
 import { ThemedSearchSidebarComponent } from './search-sidebar/themed-search-sidebar.component';
+import { NgxSkeletonLoaderModule } from 'ngx-skeleton-loader';
+import {
+  SearchResultsSkeletonComponent
+} from './search-results/search-results-skeleton/search-results-skeleton.component';
 
 const COMPONENTS = [
   SearchComponent,
@@ -62,6 +66,7 @@ const COMPONENTS = [
   ThemedSearchSettingsComponent,
   ThemedSearchFiltersComponent,
   ThemedSearchSidebarComponent,
+  SearchResultsSkeletonComponent
 ];
 
 const ENTRY_COMPONENTS = [
@@ -74,6 +79,7 @@ const ENTRY_COMPONENTS = [
   SearchFacetSelectedOptionComponent,
   SearchFacetRangeOptionComponent,
   SearchAuthorityFilterComponent,
+  SearchResultsSkeletonComponent
 ];
 
 /**
@@ -93,11 +99,12 @@ export const MODELS = [
   imports: [
     CommonModule,
     TranslateModule.forChild({
-      missingTranslationHandler: { provide: MissingTranslationHandler, useClass: MissingTranslationHelper },
+      missingTranslationHandler: {provide: MissingTranslationHandler, useClass: MissingTranslationHelper},
       useDefaultLang: true
     }),
     SharedModule.withEntryComponents(),
     NouisliderModule,
+    NgxSkeletonLoaderModule,
   ],
   exports: [
     ...COMPONENTS

src/app/shared/testing/search-configuration-service.stub.ts

@@ -13,6 +13,10 @@ export class SearchConfigurationServiceStub {
     return observableOf([]);
   }
 
+  getCurrentFilters() {
+    return observableOf([]);
+  }
+
   getCurrentScope(a) {
     return observableOf('test-id');
   }

src/config/app-config.interface.ts

@@ -23,6 +23,7 @@ import { MarkdownConfig } from './markdown-config.interface';
 import { FilterVocabularyConfig } from './filter-vocabulary-config';
 import { DiscoverySortConfig } from './discovery-sort.config';
 import { LiveRegionConfig } from '../app/shared/live-region/live-region.config';
+import { SearchConfig } from './search-page-config.interface';
 
 interface AppConfig extends Config {
   ui: UIServerConfig;
@@ -50,6 +51,7 @@ interface AppConfig extends Config {
   vocabularies: FilterVocabularyConfig[];
   comcolSelectionSort: DiscoverySortConfig;
   liveRegion: LiveRegionConfig;
+  search: SearchConfig
 }
 
 /**

src/config/default-app-config.ts

@@ -23,6 +23,7 @@ import { MarkdownConfig } from './markdown-config.interface';
 import { FilterVocabularyConfig } from './filter-vocabulary-config';
 import { DiscoverySortConfig } from './discovery-sort.config';
 import { LiveRegionConfig } from '../app/shared/live-region/live-region.config';
+import { SearchConfig } from './search-page-config.interface';
 
 export class DefaultAppConfig implements AppConfig {
   production = false;
@@ -442,4 +443,8 @@ export class DefaultAppConfig implements AppConfig {
     messageTimeOutDurationMs: 30000,
     isVisible: false,
   };
+
+  search: SearchConfig = {
+    filterPlaceholdersCount: 5
+  };
 }

src/config/search-page-config.interface.ts

@@ -0,0 +1,12 @@
+import { Config } from './config.interface';
+
+export interface SearchConfig extends Config {
+  /**
+   * Number used to render n UI elements called loading skeletons that act as placeholders.
+   * These elements indicate that some content will be loaded in their stead.
+   * Since we don't know how many filters will be loaded before we receive a response from the server we use this parameter for the skeletons count.
+   * For instance if we set 5 then 5 loading skeletons will be visualized before the actual filters are retrieved.
+   */
+  filterPlaceholdersCount?: number;
+
+}

src/config/universal-config.interface.ts

@@ -18,4 +18,13 @@ export interface UniversalConfig extends Config {
    * Paths to enable SSR for. Defaults to the home page and paths in the sitemap.
    */
   paths: Array<string>;
+  /**
+   * Whether to enable rendering of search component on SSR
+   */
+  enableSearchComponent: boolean;
+
+  /**
+   * Whether to enable rendering of browse component on SSR
+   */
+  enableBrowseComponent: boolean;
 }

src/environments/environment.production.ts

@@ -10,5 +10,7 @@ export const environment: Partial<BuildConfig> = {
     time: false,
     inlineCriticalCss: false,
     paths: [ '/home', '/items/', '/entities/', '/collections/', '/communities/', '/bitstream/', '/bitstreams/', '/handle/' ],
-  }
+    enableSearchComponent: false,
+    enableBrowseComponent: false,
+  },
 };

src/environments/environment.test.ts

@@ -13,6 +13,8 @@ export const environment: BuildConfig = {
     time: false,
     inlineCriticalCss: false,
     paths: [ '/home', '/items/', '/entities/', '/collections/', '/communities/', '/bitstream/', '/bitstreams/', '/handle/' ],
+    enableSearchComponent: false,
+    enableBrowseComponent: false,
   },
 
   // Angular Universal server settings.
@@ -321,4 +323,8 @@ export const environment: BuildConfig = {
     messageTimeOutDurationMs: 30000,
     isVisible: false,
   },
+
+  search: {
+    filterPlaceholdersCount: 5
+  }
 };

src/environments/environment.ts

@@ -15,7 +15,9 @@ export const environment: Partial<BuildConfig> = {
     time: false,
     inlineCriticalCss: false,
     paths: [ '/home', '/items/', '/entities/', '/collections/', '/communities/', '/bitstream/', '/bitstreams/', '/handle/' ],
-  }
+    enableSearchComponent: false,
+    enableBrowseComponent: false,
+  },
 };
 
 /*

src/styles/_custom_variables.scss

@@ -138,4 +138,16 @@
   --green1: #1FB300;  // This variable represents the success color for the Klaro cookie banner
   --button-text-color-cookie: #333; // This variable represents the text color for buttons in the Klaro cookie banner
   --very-dark-cyan: #215E50; // This variable represents the background color of the save cookies button
+
+  --ds-search-skeleton-text-height: 20px;
+  --ds-search-skeleton-badge-height: 18px;
+  --ds-search-skeleton-thumbnail-margin: 1em;
+  --ds-search-skeleton-text-line-count: 2;
+  --ds-search-skeleton-badge-width: 75px;
+  --ds-search-skeleton-filter-badge-width: 200px;
+  --ds-search-skeleton-info-width: 200px;
+  --ds-search-skeleton-card-height: 435px;
+
+  --ds-filters-skeleton-height: 40px;
+  --ds-filters-skeleton-spacing: 12px;
 }

src/themes/custom/lazy-theme.module.ts

@@ -159,6 +159,8 @@ import { RequestCopyModule } from 'src/app/request-copy/request-copy.module';
 import {UserMenuComponent} from './app/shared/auth-nav-menu/user-menu/user-menu.component';
 import { BrowseByComponent } from './app/shared/browse-by/browse-by.component';
 import { RegisterEmailFormComponent } from './app/register-email-form/register-email-form.component';
+import { NgxSkeletonLoaderModule } from 'ngx-skeleton-loader';
+
 
 const DECLARATIONS = [
   FileSectionComponent,
@@ -305,6 +307,7 @@ const DECLARATIONS = [
     NgxGalleryModule,
     FormModule,
     RequestCopyModule,
+    NgxSkeletonLoaderModule
   ],
   declarations: DECLARATIONS,
   exports: [

src/themes/dspace/styles/_theme_css_variable_overrides.scss

@@ -18,6 +18,7 @@
 
   /* set the next two properties as `--ds-header-navbar-border-bottom-*`
   in order to keep the bottom border of the header when navbar is expanded */
+
   --ds-expandable-navbar-border-top-color: #{$white};
   --ds-expandable-navbar-border-top-height: 0;
   --ds-expandable-navbar-padding-top: 0;

yarn.lock

@@ -8415,6 +8415,14 @@ ngx-pagination@6.0.3:
   dependencies:
     tslib "^2.3.0"
 
+ngx-skeleton-loader@^7.0.0:
+  version "7.0.0"
+  resolved "https://registry.yarnpkg.com/ngx-skeleton-loader/-/ngx-skeleton-loader-7.0.0.tgz#3b1325025a7208a20f3a0fdba6e578532a09cfcd"
+  integrity sha512-myc6GNcNhyksZrimIFkCxeihi0kQ8JhQVZiGbtiIv4gYrnnRk5nXbs3kYitK8E8OstHG+jlsmRofqGBxuIsYTA==
+  dependencies:
+    perf-marks "^1.13.4"
+    tslib "^2.0.0"
+
 ngx-sortablejs@^11.1.0:
   version "11.1.0"
   resolved "https://registry.npmjs.org/ngx-sortablejs/-/ngx-sortablejs-11.1.0.tgz"
@@ -9060,6 +9068,13 @@ pend@~1.2.0:
   resolved "https://registry.npmjs.org/pend/-/pend-1.2.0.tgz"
   integrity sha512-F3asv42UuXchdzt+xXqfW1OGlVBe+mxa2mqI0pg5yAHZPvFmY3Y6drSf/GQ1A86WgWEN9Kzh/WrgKa6iGcHXLg==
 
+perf-marks@^1.13.4:
+  version "1.14.2"
+  resolved "https://registry.yarnpkg.com/perf-marks/-/perf-marks-1.14.2.tgz#7511c24239b9c2071717993a33ec3057f387b8c7"
+  integrity sha512-N0/bQcuTlETpgox/DsXS1voGjqaoamMoiyhncgeW3rSHy/qw8URVgmPRYfFDQns/+C6yFUHDbeSBGL7ixT6Y4A==
+  dependencies:
+    tslib "^2.1.0"
+
 performance-now@^2.1.0:
   version "2.1.0"
   resolved "https://registry.npmjs.org/performance-now/-/performance-now-2.1.0.tgz"