[CSTPER-869] validator to check if a group already exists

src/app/access-control/group-registry/group-form/group-form.component.ts

@@ -1,4 +1,4 @@
-import { Component, EventEmitter, HostListener, OnDestroy, OnInit, Output } from '@angular/core';
+import { Component, EventEmitter, HostListener, OnDestroy, OnInit, Output, ChangeDetectorRef } from '@angular/core';
 import { FormGroup } from '@angular/forms';
 import { ActivatedRoute, Router } from '@angular/router';
 import { NgbModal } from '@ng-bootstrap/ng-bootstrap';
@@ -16,7 +16,7 @@ import {
   of as observableOf,
   Subscription,
 } from 'rxjs';
-import { catchError, map, switchMap, take, filter } from 'rxjs/operators';
+import { catchError, map, switchMap, take, filter, debounceTime } from 'rxjs/operators';
 import { getCollectionEditRolesRoute } from '../../../collection-page/collection-page-routing-paths';
 import { getCommunityEditRolesRoute } from '../../../community-page/community-page-routing-paths';
 import { DSpaceObjectDataService } from '../../../core/data/dspace-object-data.service';
@@ -45,6 +45,7 @@ import { NotificationsService } from '../../../shared/notifications/notification
 import { followLink } from '../../../shared/utils/follow-link-config.model';
 import { NoContent } from '../../../core/shared/NoContent.model';
 import { Operation } from 'fast-json-patch';
+import { ValidateGroupExists } from './validators/group-exists.validator';
 
 @Component({
   selector: 'ds-group-form',
@@ -126,6 +127,12 @@ export class GroupFormComponent implements OnInit, OnDestroy {
    */
   public AlertTypeEnum = AlertType;
 
+  /**
+   * Subscription to email field value change
+   */
+  groupNameValueChangeSubscribe: Subscription;
+
+
   constructor(public groupDataService: GroupDataService,
     private ePersonDataService: EPersonDataService,
     private dSpaceObjectDataService: DSpaceObjectDataService,
@@ -136,7 +143,8 @@ export class GroupFormComponent implements OnInit, OnDestroy {
     protected router: Router,
     private authorizationService: AuthorizationDataService,
     private modalService: NgbModal,
-    public requestService: RequestService) {
+    public requestService: RequestService,
+    protected changeDetectorRef: ChangeDetectorRef) {
   }
 
   ngOnInit() {
@@ -192,6 +200,14 @@ export class GroupFormComponent implements OnInit, OnDestroy {
         this.groupDescription,
       ];
       this.formGroup = this.formBuilderService.createFormGroup(this.formModel);
+
+      if (!!this.formGroup.controls.groupName && !this.formGroup.controls.groupName.value) {
+        this.formGroup.controls.groupName.setAsyncValidators(ValidateGroupExists.createValidator(this.groupDataService));
+        this.groupNameValueChangeSubscribe = this.groupName.valueChanges.pipe(debounceTime(300)).subscribe(() => {
+          this.changeDetectorRef.detectChanges();
+        });
+      }
+
       this.subs.push(
         observableCombineLatest(
           this.groupDataService.getActiveGroup(),

src/app/access-control/group-registry/group-form/validators/group-exists.validator.ts

@@ -0,0 +1,34 @@
+import { AbstractControl, ValidationErrors } from '@angular/forms';
+import { Observable } from 'rxjs';
+import { map, filter } from 'rxjs/operators';
+
+import { buildPaginatedList, PaginatedList } from '../../../../core/data/paginated-list.model';
+import { GroupDataService } from '../../../../core/eperson/group-data.service';
+import { getFirstSucceededRemoteData,getFirstSucceededRemoteListPayload } from '../../../../core/shared/operators';
+import { Group } from '../../../../core/eperson/models/group.model';
+
+export class ValidateGroupExists {
+
+  /**
+   * This method will create the validator with the groupDataService requested from component
+   * @param groupDataService the service with DI in the component that this validator is being utilized.
+   * @return Observable<ValidationErrors | null>
+   */
+  static createValidator(groupDataService: GroupDataService) {
+    return (control: AbstractControl): Promise<ValidationErrors | null> | Observable<ValidationErrors | null> => {
+      return groupDataService.searchGroups(control.value, {
+            currentPage: 1,
+            elementsPerPage: 100
+          })
+        .pipe(
+          getFirstSucceededRemoteListPayload(),
+          map( (groups: Group[]) => {
+            return groups.filter(group => group.name === control.value);
+          }),
+          map( (groups: Group[]) => {
+            return groups.length > 0 ? { groupExists: true } : null;
+          }),
+        );
+    };
+  }
+}

src/assets/i18n/en.json5

@@ -1351,6 +1351,8 @@
 
   "error.validation.emailTaken": "This E-mail is already taken",
 
+  "error.validation.groupExists": "This group already exists",
+
 
   "file-section.error.header": "Error obtaining files for this item",