fix infinite loop

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

@@ -1,34 +1,61 @@
-import { Injectable } from '@angular/core';
-import { RequestService } from './request.service';
-import { HALEndpointService } from '../shared/hal-endpoint.service';
-import { RemoteDataBuildService } from '../cache/builders/remote-data-build.service';
-import { hasValue, hasValueOperator, isNotEmpty, isNotEmptyOperator } from '../../shared/empty.util';
-import { distinctUntilChanged, filter, map, mergeMap, skipWhile, startWith, switchMap, take, tap } from 'rxjs/operators';
-import { configureRequest, getRemoteDataPayload, getResponseFromEntry, getSucceededRemoteData } from '../shared/operators';
-import { DeleteRequest, FindAllOptions, PostRequest, RestRequest } from './request.models';
-import { Observable } from 'rxjs/internal/Observable';
-import { RestResponse } from '../cache/response.models';
-import { Item } from '../shared/item.model';
-import { Relationship } from '../shared/item-relationships/relationship.model';
-import { RelationshipType } from '../shared/item-relationships/relationship-type.model';
-import { RemoteData } from './remote-data';
-import { combineLatest, combineLatest as observableCombineLatest } from 'rxjs';
-import { PaginatedList } from './paginated-list';
-import { ItemDataService } from './item-data.service';
-import { compareArraysUsingIds, paginatedRelationsToItems, relationsToItems } from '../../+item-page/simple/item-types/shared/item-relationships-utils';
-import { ObjectCacheService } from '../cache/object-cache.service';
-import { DataService } from './data.service';
-import { NormalizedObjectBuildService } from '../cache/builders/normalized-object-build.service';
-import { MemoizedSelector, select, Store } from '@ngrx/store';
-import { CoreState } from '../core.reducers';
-import { NotificationsService } from '../../shared/notifications/notifications.service';
 import { HttpClient, HttpHeaders } from '@angular/common/http';
-import { DefaultChangeAnalyzer } from './default-change-analyzer.service';
-import { SearchParam } from '../cache/models/search-param.model';
-import { HttpOptions } from '../dspace-rest-v2/dspace-rest-v2.service';
+import { Injectable } from '@angular/core';
+import { MemoizedSelector, select, Store } from '@ngrx/store';
+import { combineLatest, combineLatest as observableCombineLatest } from 'rxjs';
+import { Observable } from 'rxjs/internal/Observable';
+import {
+  distinctUntilChanged,
+  filter,
+  map,
+  mergeMap,
+  startWith,
+  switchMap,
+  take,
+  tap
+} from 'rxjs/operators';
+import {
+  compareArraysUsingIds,
+  paginatedRelationsToItems,
+  relationsToItems
+} from '../../+item-page/simple/item-types/shared/item-relationships-utils';
 import { AppState, keySelector } from '../../app.reducer';
+import {
+  hasValue,
+  hasValueOperator,
+  isNotEmpty,
+  isNotEmptyOperator
+} from '../../shared/empty.util';
+import { ReorderableRelationship } from '../../shared/form/builder/ds-dynamic-form-ui/existing-metadata-list-element/existing-metadata-list-element.component';
+import {
+  RemoveNameVariantAction,
+  SetNameVariantAction
+} from '../../shared/form/builder/ds-dynamic-form-ui/relation-lookup-modal/name-variant.actions';
 import { NameVariantListState } from '../../shared/form/builder/ds-dynamic-form-ui/relation-lookup-modal/name-variant.reducer';
-import { RemoveNameVariantAction, SetNameVariantAction } from '../../shared/form/builder/ds-dynamic-form-ui/relation-lookup-modal/name-variant.actions';
+import { NotificationsService } from '../../shared/notifications/notifications.service';
+import { NormalizedObjectBuildService } from '../cache/builders/normalized-object-build.service';
+import { RemoteDataBuildService } from '../cache/builders/remote-data-build.service';
+import { SearchParam } from '../cache/models/search-param.model';
+import { ObjectCacheService } from '../cache/object-cache.service';
+import { RestResponse } from '../cache/response.models';
+import { CoreState } from '../core.reducers';
+import { HttpOptions } from '../dspace-rest-v2/dspace-rest-v2.service';
+import { HALEndpointService } from '../shared/hal-endpoint.service';
+import { RelationshipType } from '../shared/item-relationships/relationship-type.model';
+import { Relationship } from '../shared/item-relationships/relationship.model';
+import { Item } from '../shared/item.model';
+import {
+  configureRequest,
+  getRemoteDataPayload,
+  getResponseFromEntry,
+  getSucceededRemoteData
+} from '../shared/operators';
+import { DataService } from './data.service';
+import { DefaultChangeAnalyzer } from './default-change-analyzer.service';
+import { ItemDataService } from './item-data.service';
+import { PaginatedList } from './paginated-list';
+import { RemoteData, RemoteDataState } from './remote-data';
+import { DeleteRequest, FindAllOptions, PostRequest, RestRequest } from './request.models';
+import { RequestService } from './request.service';
 
 const relationshipListsStateSelector = (state: AppState) => state.relationshipLists;
 
@@ -116,9 +143,9 @@ export class RelationshipService extends DataService<Relationship> {
     this.findById(relationshipId).pipe(
       getSucceededRemoteData(),
       getRemoteDataPayload(),
-      switchMap((relationship: Relationship) => combineLatest(
-        relationship.leftItem.pipe(getSucceededRemoteData(), getRemoteDataPayload()),
-        relationship.rightItem.pipe(getSucceededRemoteData(), getRemoteDataPayload())
+      switchMap((rel: Relationship) => combineLatest(
+        rel.leftItem.pipe(getSucceededRemoteData(), getRemoteDataPayload()),
+        rel.rightItem.pipe(getSucceededRemoteData(), getRemoteDataPayload())
         )
       ),
       take(1)
@@ -336,20 +363,26 @@ export class RelationshipService extends DataService<Relationship> {
       )
   }
 
-  public updatePlace(relationship: Relationship, newIndex: number, left: boolean): Observable<RemoteData<Relationship>> {
+  public updatePlace(reoRel: ReorderableRelationship): Observable<RemoteData<Relationship>> {
     let updatedRelationship;
-    if (left) {
-      updatedRelationship = Object.assign(new Relationship(), relationship, { leftPlace: newIndex });
+    if (reoRel.useLeftItem) {
+      updatedRelationship = Object.assign(new Relationship(), reoRel.relationship, { rightPlace: reoRel.newIndex });
     } else {
-      updatedRelationship = Object.assign(new Relationship(), relationship, { rightPlace: newIndex });
+      updatedRelationship = Object.assign(new Relationship(), reoRel.relationship, { leftPlace: reoRel.newIndex });
     }
-    return this.update(updatedRelationship).pipe(
-      tap((relationshipRD: RemoteData<Relationship>) => {
-        if (relationshipRD.hasSucceeded) {
-          this.removeRelationshipItemsFromCacheByRelationship(relationship.id);
+
+    const update$ = this.update(updatedRelationship);
+
+    update$.pipe(
+      filter((relationshipRD: RemoteData<Relationship>) => relationshipRD.state === RemoteDataState.ResponsePending),
+      take(1),
+    ).subscribe((relationshipRD: RemoteData<Relationship>) => {
+      if (relationshipRD.state === RemoteDataState.ResponsePending) {
+        this.removeRelationshipItemsFromCacheByRelationship(reoRel.relationship.id);
       }
-      })
-    );
+    });
+
+    return update$;
   }
 
 }

src/app/shared/form/builder/ds-dynamic-form-ui/ds-dynamic-form-control-container.component.ts

@@ -340,16 +340,16 @@ export class DsDynamicFormControlContainerComponent extends DynamicFormControlCo
   moveSelection(event: CdkDragDrop<Relationship>) {
     this.zone.runOutsideAngular(() => {
       moveItemInArray(this.reorderables, event.previousIndex, event.currentIndex);
-      const relationships = this.reorderables.map((reo: Reorderable, index: number) => {
+      const reorderables = this.reorderables.map((reo: Reorderable, index: number) => {
           reo.oldIndex = reo.getPlace();
           reo.newIndex = index;
           return reo;
         }
       );
-      return observableCombineLatest(relationships.map((rel: ReorderableRelationship) => {
+      return observableCombineLatest(reorderables.map((rel: ReorderableRelationship) => {
           console.log(rel);
           if (rel.oldIndex !== rel.newIndex) {
-            return this.relationshipService.updatePlace(rel.relationship, rel.newIndex, !rel.useLeftItem);
+            return this.relationshipService.updatePlace(rel);
           } else {
             return observableOf(undefined);
           }