Fixed dropdown/lookup & lookup-name fields being reset when hitting enter (DSpace#3724)

Author: alexandrevryghem

src/app/shared/form/builder/ds-dynamic-form-ui/models/lookup/dynamic-lookup.component.html

@@ -94,11 +94,12 @@
          (scrolled)="onScroll()"
          [scrollWindow]="false">
 
-      <button class="dropdown-item disabled"
+      <button class="dropdown-item disabled" type="button"
               *ngIf="optionsList && optionsList.length === 0"
-              (click)="$event.stopPropagation(); clearFields(); sdRef.close();">{{'form.no-results' | translate}}
+              (click)="$event.stopPropagation(); clearFields(); sdRef.close();">
+        {{ 'form.no-results' | translate }}
       </button>
-      <button class="dropdown-item lookup-item"
+      <button class="dropdown-item lookup-item" type="button"
               *ngFor="let listEntry of optionsList"
               (click)="$event.stopPropagation(); onSelect(listEntry); sdRef.close();"
               title="{{ listEntry.display }}">

src/app/shared/form/builder/ds-dynamic-form-ui/models/scrollable-dropdown/dynamic-scrollable-dropdown.component.html

@@ -40,17 +40,19 @@
          (scrolled)="onScroll()"
          [scrollWindow]="false">
 
-      <button class="dropdown-item disabled" *ngIf="optionsList && optionsList.length === 0">{{'form.no-results' | translate}}</button>
+      <button class="dropdown-item disabled" type="button" *ngIf="optionsList && optionsList.length === 0">
+        {{ 'form.no-results' | translate }}
+      </button>
       <button class="dropdown-item collection-item text-truncate"
               (click)="onSelect(undefined); sdRef.close()" (mousedown)="onSelect(undefined); sdRef.close()"
               title="{{ 'dropdown.clear.tooltip' | translate }}" role="option"
-      >
+              type="button">
         <i>{{ 'dropdown.clear' | translate }}</i>
       </button>
       <button class="dropdown-item collection-item text-truncate" *ngFor="let listEntry of optionsList; let i = index"
               [class.active]="i === selectedIndex"
               (keydown.enter)="onSelect(listEntry); sdRef.close()" (mousedown)="onSelect(listEntry); sdRef.close()"
-              title="{{ listEntry.display }}" role="option"
+              title="{{ listEntry.display }}" role="option" type="button"
               [attr.id]="listEntry.display === (currentValue|async) ? ('combobox_' + id + '_selected') : null">
         {{inputFormatter(listEntry)}}
       </button>

src/app/shared/form/form.service.ts

@@ -153,6 +153,9 @@ export class FormService {
   }
 
   public addControlErrors(field: AbstractControl, formId: string, fieldId: string, fieldIndex: number) {
+    if (field.errors === null) {
+      return;
+    }
     const errors: string[] = Object.keys(field.errors)
       .filter((errorKey) => field.errors[errorKey] === true)
       .map((errorKey) => `error.validation.${errorKey}`);