Fixed creation & deletion of relationships not working correctly & added same entity type relationship support

src/app/app.component.ts

@@ -32,6 +32,7 @@ import {
   Observable,
 } from 'rxjs';
 import {
+  delay,
   distinctUntilChanged,
   take,
   withLatestFrom,
@@ -136,7 +137,10 @@ export class AppComponent implements OnInit, AfterViewInit {
   }
 
   ngAfterViewInit() {
-    this.router.events.subscribe((event) => {
+    this.router.events.pipe(
+      // delay(0) to prevent "Expression has changed after it was checked" errors
+      delay(0),
+    ).subscribe((event) => {
       if (event instanceof NavigationStart) {
         distinctNext(this.isRouteLoading$, true);
       } else if (

src/app/core/data/object-updates/object-updates.reducer.ts

@@ -61,6 +61,8 @@ export interface VirtualMetadataSource {
 
 export interface RelationshipIdentifiable extends Identifiable {
   nameVariant?: string;
+  originalItem: Item;
+  originalIsLeft: boolean
   relatedItem: Item;
   relationship: Relationship;
   type: RelationshipType;

src/app/core/data/object-updates/object-updates.service.ts

@@ -15,6 +15,7 @@
   filter,
   map,
   switchMap,
+  take,
 } from 'rxjs/operators';
 
 import {
@@ -212,17 +213,29 @@
    * @param url The page's URL for which the changes are saved
    * @param field An updated field for the page's object
    */
-  saveAddFieldUpdate(url: string, field: Identifiable) {
+  saveAddFieldUpdate(url: string, field: Identifiable): Observable<boolean> {
+    const update$: Observable<boolean> = this.getFieldUpdatesExclusive(url, [field]).pipe(
+      filter((fieldUpdates: FieldUpdates) => fieldUpdates[field.uuid].changeType === FieldChangeType.ADD),
+      take(1),
+      map(() => true),
+    );
     this.saveFieldUpdate(url, field, FieldChangeType.ADD);
+    return update$;
   }
 
   /**
    * Calls the saveFieldUpdate method with FieldChangeType.REMOVE
    * @param url The page's URL for which the changes are saved
    * @param field An updated field for the page's object
    */
-  saveRemoveFieldUpdate(url: string, field: Identifiable) {
+  saveRemoveFieldUpdate(url: string, field: Identifiable): Observable<boolean> {
+    const update$: Observable<boolean> = this.getFieldUpdatesExclusive(url, [field]).pipe(
+      filter((fieldUpdates: FieldUpdates) => fieldUpdates[field.uuid].changeType === FieldChangeType.REMOVE),
+      take(1),
+      map(() => true),
+    );
     this.saveFieldUpdate(url, field, FieldChangeType.REMOVE);
+    return update$;
   }
 
   /**

src/app/core/data/relationship-data.service.ts

@@ -155,8 +155,11 @@
    * @param id                    the ID of the relationship to delete
    * @param copyVirtualMetadata   whether to copy this relationship's virtual metadata to the related Items
    *                              accepted values: none, all, left, right, configured
+   * @param shouldRefresh         refresh the cache for the items in the relationship after creating
+   *                              it. Disable this if you want to add relationships in bulk, and
+   *                              want to refresh the cachemanually at the end
    */
-  deleteRelationship(id: string, copyVirtualMetadata: string): Observable<RemoteData<NoContent>> {
+  deleteRelationship(id: string, copyVirtualMetadata: string, shouldRefresh = true): Observable<RemoteData<NoContent>> {
     return this.getRelationshipEndpoint(id).pipe(
       isNotEmptyOperator(),
       take(1),
@@ -167,7 +170,11 @@
       sendRequest(this.requestService),
       switchMap((restRequest: RestRequest) => this.rdbService.buildFromRequestUUID(restRequest.uuid)),
       getFirstCompletedRemoteData(),
-      tap(() => this.refreshRelationshipItemsInCacheByRelationship(id)),
+      tap(() => {
+        if (shouldRefresh) {
+          this.refreshRelationshipItemsInCacheByRelationship(id);
+        }
+      }),
     );
   }
 
@@ -178,8 +185,11 @@
    * @param item2 The second item of the relationship
    * @param leftwardValue The leftward value of the relationship
    * @param rightwardValue The rightward value of the relationship
+   * @param shouldRefresh refresh the cache for the items in the relationship after creating it.
+   *                      Disable this if you want to add relationships in bulk, and want to refresh
+   *                      the cache manually at the end
    */
-  addRelationship(typeId: string, item1: Item, item2: Item, leftwardValue?: string, rightwardValue?: string): Observable<RemoteData<Relationship>> {
+  addRelationship(typeId: string, item1: Item, item2: Item, leftwardValue?: string, rightwardValue?: string, shouldRefresh = true): Observable<RemoteData<Relationship>> {
     const options: HttpOptions = Object.create({});
     let headers = new HttpHeaders();
     headers = headers.append('Content-Type', 'text/uri-list');
@@ -194,8 +204,12 @@
       sendRequest(this.requestService),
       switchMap((restRequest: RestRequest) => this.rdbService.buildFromRequestUUID(restRequest.uuid)),
       getFirstCompletedRemoteData(),
-      tap(() => this.refreshRelationshipItemsInCache(item1)),
-      tap(() => this.refreshRelationshipItemsInCache(item2)),
+      tap(() => {
+        if (shouldRefresh) {
+          this.refreshRelationshipItemsInCache(item1);
+          this.refreshRelationshipItemsInCache(item2);
+        }
+      }),
     ) as Observable<RemoteData<Relationship>>;
   }
 
@@ -223,7 +237,7 @@
    * Method to remove an item that's part of a relationship from the cache
    * @param item The item to remove from the cache
    */
-  public refreshRelationshipItemsInCache(item) {
+  public refreshRelationshipItemsInCache(item: Item): void {
     this.objectCache.remove(item._links.self.href);
     this.requestService.removeByHrefSubstring(item.uuid);
     observableCombineLatest([
@@ -336,7 +350,19 @@
     } else {
       findListOptions.searchParams = searchParams;
     }
-    return this.searchBy('byLabel', findListOptions, useCachedVersionIfAvailable, reRequestOnStale, ...linksToFollow);
+
+    // always set reRequestOnStale to false here, so it doesn't happen automatically in BaseDataService
+    const result$ = this.searchBy('byLabel', findListOptions, useCachedVersionIfAvailable, false, ...linksToFollow);
+
+    // add this result as a dependency of the item, meaning that if the item is invalided, this
+    // result will be as well
+    this.addDependency(result$, item._links.self.href);
+
+    // do the reRequestOnStale call here, to ensure any re-requests also get added as dependencies
+    return result$.pipe(
+      this.reRequestStaleRemoteData(reRequestOnStale, () =>
+        this.getItemRelationshipsByLabel(item, label, options, useCachedVersionIfAvailable, reRequestOnStale, ...linksToFollow)),
+    );
   }
 
   /**

src/app/item-page/edit-item-page/abstract-item-update/abstract-item-update.component.ts

@@ -55,6 +55,10 @@ export class AbstractItemUpdateComponent extends AbstractTrackableComponent impl
    */
   updates$: Observable<FieldUpdates>;
 
+  hasChanges$: Observable<boolean>;
+
+  isReinstatable$: Observable<boolean>;
+
   /**
    * Route to the item's page
    */
@@ -101,10 +105,9 @@ export class AbstractItemUpdateComponent extends AbstractTrackableComponent impl
     }
 
     this.discardTimeOut = environment.item.edit.undoTimeout;
-    this.url = this.router.url;
-    if (this.url.indexOf('?') > 0) {
-      this.url = this.url.substr(0, this.url.indexOf('?'));
-    }
+    this.url = this.router.url.split('?')[0];
+    this.hasChanges$ = this.hasChanges();
+    this.isReinstatable$ = this.isReinstatable();
     this.hasChanges().pipe(first()).subscribe((hasChanges) => {
       if (!hasChanges) {
         this.initializeOriginalFields();

src/app/item-page/edit-item-page/item-bitstreams/item-bitstreams.component.html

@@ -6,21 +6,21 @@
             class="fas fa-upload"></i>
       <span class="d-none d-sm-inline">&nbsp;{{"item.edit.bitstreams.upload-button" | translate}}</span>
     </button>
-    <button class="btn btn-warning" *ngIf="isReinstatable() | async"
+    <button class="btn btn-warning" *ngIf="isReinstatable$ | async"
             [attr.aria-label]="'item.edit.bitstreams.reinstate-button' | translate"
             (click)="reinstate()"><i
             class="fas fa-undo-alt"></i>
       <span class="d-none d-sm-inline">&nbsp;{{"item.edit.bitstreams.reinstate-button" | translate}}</span>
     </button>
-    <button class="btn btn-primary" [disabled]="(hasChanges() | async) !== true || submitting"
+    <button class="btn btn-primary" [disabled]="(hasChanges$ | async) !== true || submitting"
             [attr.aria-label]="'item.edit.bitstreams.save-button' | translate"
             (click)="submit()"><i
             class="fas fa-save"></i>
       <span class="d-none d-sm-inline">&nbsp;{{"item.edit.bitstreams.save-button" | translate}}</span>
     </button>
-    <button class="btn btn-danger" *ngIf="(isReinstatable() | async) !== true"
+    <button class="btn btn-danger" *ngIf="(isReinstatable$ | async) !== true"
             [attr.aria-label]="'item.edit.bitstreams.discard-button' | translate"
-            [disabled]="(hasChanges() | async) !== true || submitting"
+            [disabled]="(hasChanges$ | async) !== true || submitting"
             (click)="discard()"><i
             class="fas fa-times"></i>
       <span class="d-none d-sm-inline">&nbsp;{{"item.edit.bitstreams.discard-button" | translate}}</span>
@@ -52,21 +52,21 @@
 
   <div class="button-row bottom">
     <div class="mt-4 float-right space-children-mr ml-gap">
-      <button class="btn btn-warning" *ngIf="isReinstatable() | async"
+      <button class="btn btn-warning" *ngIf="isReinstatable$ | async"
               [attr.aria-label]="'item.edit.bitstreams.reinstate-button' | translate"
               (click)="reinstate()"><i
         class="fas fa-undo-alt"></i>
         <span class="d-none d-sm-inline">&nbsp;{{"item.edit.bitstreams.reinstate-button" | translate}}</span>
       </button>
-      <button class="btn btn-primary" [disabled]="(hasChanges() | async) !== true || submitting"
+      <button class="btn btn-primary" [disabled]="(hasChanges$ | async) !== true || submitting"
               [attr.aria-label]="'item.edit.bitstreams.save-button' | translate"
               (click)="submit()"><i
         class="fas fa-save"></i>
         <span class="d-none d-sm-inline">&nbsp;{{"item.edit.bitstreams.save-button" | translate}}</span>
       </button>
-      <button class="btn btn-danger" *ngIf="(isReinstatable() | async) !== true"
+      <button class="btn btn-danger" *ngIf="(isReinstatable$ | async) !== true"
               [attr.aria-label]="'item.edit.bitstreams.discard-button' | translate"
-              [disabled]="(hasChanges() | async) !== true || submitting"
+              [disabled]="(hasChanges$ | async) !== true || submitting"
               (click)="discard()"><i
         class="fas fa-times"></i>
         <span class="d-none d-sm-inline">&nbsp;{{"item.edit.bitstreams.discard-button" | translate}}</span>