Merge pull request DSpace#3001 from tdonohue/port_2933_to_7x

[Port dspace-7_x] Reset dropdown values

Author: tdonohue

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

@@ -40,7 +40,13 @@
          (scrolled)="onScroll()"
          [scrollWindow]="false">
 
-      <button class="dropdown-item disabled" *ngIf="optionsList && optionsList.length == 0">{{'form.no-results' | translate}}</button>
+      <button class="dropdown-item disabled" *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"
+      >
+        <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()"

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

@@ -165,7 +165,7 @@ describe('Dynamic Dynamic Scrollable Dropdown component', () => {
         scrollableDropdownFixture.detectChanges();
 
         de = scrollableDropdownFixture.debugElement.queryAll(By.css('button.dropdown-item'));
-        btnEl = de[0].nativeElement;
+        btnEl = de[1].nativeElement;
 
         btnEl.dispatchEvent(mousedownEvent);
         scrollableDropdownFixture.detectChanges();

src/assets/i18n/en.json5

@@ -1468,6 +1468,10 @@
 
   "deny-request-copy.success": "Successfully denied item request",
 
+  "dropdown.clear": "Clear selection",
+
+  "dropdown.clear.tooltip": "Clear the selected option",
+
   "dso.name.untitled": "Untitled",
 
   "dso.name.unnamed": "Unnamed",