fixed issue with browse back button

src/app/shared/browse-by/browse-by.component.html

@@ -3,7 +3,9 @@
   <ng-container *ngComponentOutlet="getStartsWithComponent(); injector: objectInjector;"></ng-container>
   <div *ngIf="objects?.hasSucceeded && !objects?.isLoading && objects?.payload?.page.length > 0" @fadeIn>
       <div *ngIf="shouldDisplayResetButton$ |async" class="mb-2 reset">
-        <ds-themed-results-back-button [paginationConfig]="paginationConfig" [previousPage$]="previousPage$"></ds-themed-results-back-button>
+        <ds-results-back-button [paginationConfig]="paginationConfig"
+                                [previousPage$]="previousPage$"
+                                [alwaysShowButton]=true></ds-results-back-button>
       </div>
     <ds-viewable-collection
       [config]="paginationConfig"
@@ -18,7 +20,9 @@
   <ds-error *ngIf="objects?.hasFailed" message="{{'error.browse-by' | translate}}"></ds-error>
   <div *ngIf="!objects?.isLoading && objects?.payload?.page.length === 0">
     <div *ngIf="shouldDisplayResetButton$ |async" class="d-inline-block mb-4 reset">
-      <ds-themed-results-back-button [paginationConfig]="paginationConfig" [previousPage$]="previousPage$" ></ds-themed-results-back-button>
+      <ds-results-back-button [paginationConfig]="paginationConfig"
+                              [previousPage$]="previousPage$"
+                              [alwaysShowButton]=true></ds-results-back-button>
     </div>
     <div class="alert alert-info w-100" role="alert">
       {{'browse.empty' | translate}}

src/app/shared/results-back-button/results-back-button.component.html

@@ -1,4 +1,4 @@
-<button *ngIf="showBackButton | async" class="btn btn-secondary btn-sm mb-2 ng-tns-c242-28" (click)="back()">
+<button *ngIf="showBackButton" class="btn btn-secondary btn-sm mb-2 ng-tns-c242-28" (click)="back()">
   <i _ngcontent-dspace-angular-c242="" class="fas fa-arrow-left ng-tns-c242-3"></i>
   {{this.buttonLabel | async}}
 </button>

src/app/shared/results-back-button/results-back-button.component.ts

@@ -30,9 +30,17 @@ export class ResultsBackButtonComponent {
   @Input() paginationConfig?: PaginationComponentOptions;
 
   /**
-   * Used to configure search in mirador.
+   * Tells component to always show the back button.
+   * When not true the button is displayed based on
+   * the previous route.
    */
-  showBackButton: Observable<boolean>;
+  @Input() alwaysShowButton?: boolean;
+
+  /**
+   * Always show back button when true regardless of
+   * previous route.
+   */
+  showBackButton: boolean;
 
   /**
    * The button text
@@ -52,12 +60,21 @@ export class ResultsBackButtonComponent {
     } else {
       this.buttonLabel = this.translateService.get('search.browse.item-back');
     }
-    // Show the back to results button when the previous context was a search or browse list.
+
-    this.showBackButton = this.routeService.getPreviousUrl().pipe(
+    if(this.alwaysShowButton) {
-      filter(url => /^(\/search|\/browse|\/collections|\/admin\/search|\/mydspace)/.test(url)),
+      this.showBackButton = true;
-      take(1),
+    }
-      map(() => true)
+    else {
-    );
+      // Show the back button when the previous route was a search or browse list.
+      // Include the button for admin search results and MyDspace.
+      this.routeService.getPreviousUrl().pipe(
+        filter(url => /^(\/search|\/browse|\/collections|\/admin\/search|\/mydspace)/.test(url)),
+        take(1),
+        map(() => true)
+      ).subscribe(showButton => {
+        this.showBackButton = showButton;
+      });
+    }
   }
 
   /**
@@ -72,7 +89,9 @@ export class ResultsBackButtonComponent {
       this.routeService.getPreviousUrl().pipe(
         take(1)
       ).subscribe(
-        (url => this.router.navigateByUrl(url))
+        (url => {
+          this.router.navigateByUrl(url)
+        })
       );
     }
   }

src/app/shared/results-back-button/themed-results-back-button.component.ts

@@ -11,10 +11,6 @@ import { BehaviorSubject } from 'rxjs';
 })
 export class ThemedResultsBackButtonComponent extends ThemedComponent<ResultsBackButtonComponent> {
 
-  @Input() previousPage$?: BehaviorSubject<string>;
-
-  @Input() paginationConfig?: PaginationComponentOptions;
-
   protected getComponentName(): string {
     return 'ResultsBackButtonComponent';
   }

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

@@ -81,20 +81,20 @@ const DECLARATIONS = [
 ];
 
 @NgModule({
-  imports: [
+    imports: [
-    CommonModule,
+        CommonModule,
-    SharedModule,
+        SharedModule,
-    RootModule,
+        RootModule,
-    NavbarModule,
+        NavbarModule,
-    SharedBrowseByModule,
+        SharedBrowseByModule,
-    ResultsBackButtonModule,
+        ResultsBackButtonModule,
-    ItemPageModule,
+        ItemPageModule,
-    ItemSharedModule,
+        ItemSharedModule,
-  ],
+    ],
-  declarations: DECLARATIONS,
+    declarations: DECLARATIONS,
-  providers: [
+    providers: [
-    ...ENTRY_COMPONENTS.map((component) => ({ provide: component }))
+        ...ENTRY_COMPONENTS.map((component) => ({provide: component}))
-  ],
+    ],
 })
 /**
  * This module is included in the main bundle that gets downloaded at first page load. So it should