[DSC-2005] fix one box clear on input

Author: FrancescoMolinaro

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

@@ -293,6 +293,19 @@ describe('DsDynamicOneboxComponent test suite', () => {
 
       });
 
+      it('should clear inputValue when input is emptied after a value was set', () => {
+        const inputDe = oneboxCompFixture.debugElement.query(By.css('input.form-control'));
+        const inputElement = inputDe.nativeElement;
+
+        inputElement.value = 'test value';
+        inputElement.dispatchEvent(new Event('input'));
+        expect(oneboxComponent.inputValue).toEqual(new FormFieldMetadataValueObject('test value'));
+
+        inputElement.value = '';
+        inputElement.dispatchEvent(new Event('input'));
+        expect(oneboxComponent.inputValue).toBeNull();
+      });
+
       it('should emit blur Event onBlur when popup is closed', () => {
         spyOn(oneboxComponent.blur, 'emit');
         spyOn(oneboxComponent.instance, 'isPopupOpen').and.returnValue(false);

src/app/shared/form/builder/ds-dynamic-form-ui/models/onebox/dynamic-onebox.component.ts

@@ -238,6 +238,8 @@ export class DsDynamicOneboxComponent extends DsDynamicVocabularyComponent imple
           this.inputValue.securityLevel = (this.model.value as any).securityLevel;
         }
       }
+    } else if (isEmpty(event.target.value)) {
+      this.inputValue = null;
     }
   }