77742: Collection template-item loading indicator and error alert

src/app/+collection-page/edit-item-template-page/edit-item-template-page.component.html

@@ -6,6 +6,8 @@
         <ds-item-metadata [updateService]="itemTemplateService" [item]="itemRD?.payload"></ds-item-metadata>
         <button [routerLink]="getCollectionEditUrl(collection)" class="btn btn-outline-secondary">{{ 'collection.edit.template.cancel' | translate }}</button>
       </ng-container>
+      <ds-loading *ngIf="itemRD?.isLoading" [message]="'collection.edit.template.loading' | translate"></ds-loading>
+      <ds-alert *ngIf="itemRD?.hasFailed" [type]="AlertTypeEnum.Error" [content]="'collection.edit.template.error' | translate"></ds-alert>
     </div>
   </div>
 </div>

src/app/+collection-page/edit-item-template-page/edit-item-template-page.component.ts

@@ -8,6 +8,7 @@ import { ItemTemplateDataService } from '../../core/data/item-template-data.serv
 import { getCollectionEditRoute } from '../collection-page-routing-paths';
 import { Item } from '../../core/shared/item.model';
 import { getFirstSucceededRemoteDataPayload } from '../../core/shared/operators';
+import { AlertType } from '../../shared/alert/aletr-type';
 
 @Component({
   selector: 'ds-edit-item-template-page',
@@ -28,6 +29,12 @@ export class EditItemTemplatePageComponent implements OnInit {
    */
   itemRD$: Observable<RemoteData<Item>>;
 
+  /**
+   * The AlertType enumeration
+   * @type {AlertType}
+   */
+  AlertTypeEnum = AlertType;
+
   constructor(protected route: ActivatedRoute,
               public itemTemplateService: ItemTemplateDataService) {
   }

src/assets/i18n/en.json5

@@ -777,10 +777,14 @@
 
   "collection.edit.template.edit-button": "Edit",
 
+  "collection.edit.template.error": "An error occurred retrieving the template item",
+
   "collection.edit.template.head": "Edit Template Item for Collection \"{{ collection }}\"",
 
   "collection.edit.template.label": "Template item",
 
+  "collection.edit.template.loading": "Loading template item...",
+
   "collection.edit.template.notifications.delete.error": "Failed to delete the item template",
 
   "collection.edit.template.notifications.delete.success": "Successfully deleted the item template",