Adding the aria-label attribute to buttons

(cherry picked from commit 9565f9b)

Author: Andrea-Guevara

src/app/shared/form/vocabulary-treeview/vocabulary-treeview.component.html

@@ -6,16 +6,20 @@
              [attr.aria-label]="'vocabulary-treeview.search.form.search-placeholder' | translate"
              [placeholder]="'vocabulary-treeview.search.form.search-placeholder' | translate">
       <div class="input-group-append" id="button-addon4">
-        <button class="btn btn-outline-primary" type="button" (click)="search()" [disabled]="!isSearchEnabled()">
+        <button class="btn btn-outline-primary" type="button" (click)="search()" [disabled]="!isSearchEnabled()"
+                [attr.aria-label]="'vocabulary-treeview.search.form.search' | translate">
           {{'vocabulary-treeview.search.form.search' | translate}}
         </button>
-        <button class="btn btn-outline-secondary" type="button" (click)="reset()">
+        <button class="btn btn-outline-secondary" type="button" (click)="reset()"
+                [attr.aria-label]="'vocabulary-treeview.search.form.reset' | translate">
           {{'vocabulary-treeview.search.form.reset' | translate}}
         </button>
-        <button *ngIf="showAdd && this.vocabularyOptions.closed" class="btn btn-outline-primary" type="button" (click)="add()">
+        <button *ngIf="showAdd && this.vocabularyOptions.closed" class="btn btn-outline-primary" type="button" (click)="add()"
+                [attr.aria-label]="'vocabulary-treeview.search.form.add' | translate">
           {{'vocabulary-treeview.search.form.add' | translate}}
         </button>
-        <button class="btn btn-outline-primary" type="button" (click)="add()" [disabled]="this.vocabularyOptions.closed">
+        <button class="btn btn-outline-primary" type="button" (click)="add()" [disabled]="this.vocabularyOptions.closed"
+                [attr.aria-label]="'vocabulary-treeview.search.form.add' | translate">
           {{'vocabulary-treeview.search.form.add' | translate}}
         </button>
       </div>
@@ -91,13 +95,15 @@ <h2 *ngIf="(loading | async) !== true && dataSource.data.length === 0" class="h4
     </cdk-tree-node>
 
     <cdk-tree-node *cdkTreeNodeDef="let node; when: isLoadMore" cdkTreeNodePadding>
-      <button class="btn btn-outline-secondary btn-sm" (click)="loadMore(node.loadMoreParentItem)">
+      <button class="btn btn-outline-secondary btn-sm" (click)="loadMore(node.loadMoreParentItem)"
+              [attr.aria-label]="'vocabulary-treeview.load-more' | translate">
         {{'vocabulary-treeview.load-more' | translate}}...
       </button>
     </cdk-tree-node>
 
     <cdk-tree-node *cdkTreeNodeDef="let node; when: isLoadMoreRoot">
-      <button class="btn btn-outline-secondary btn-sm" (click)="loadMoreRoot(node)">
+      <button class="btn btn-outline-secondary btn-sm" (click)="loadMoreRoot(node)"
+              [attr.aria-label]="'vocabulary-treeview.load-more' | translate">
         {{'vocabulary-treeview.load-more' | translate}}...
       </button>
     </cdk-tree-node>