ReactiveDropdownSearchMultiSelection - Validators.required works only once

[leaderrr767]

Hi, folks.

Validators.required works only once for ReactiveDropdownSearchMultiSelection.

How to reproduce:

1. Run the code
2. Press "Validate!" -> Validation message "Required!" appears. Good.
3. Choose 1 or more items within ReactiveDropdownSearchMultiSelection -> Validation message "Required!" disappears. Good.
4. Remove all items from ReactiveDropdownSearchMultiSelection -> Validation message "Required!" don't appear.
5. Press "Validate!" -> Validation message "Required!" don't appear. Sad.

Update:
As a walkaround I use Validators.Required in combination with Validators.minLength(1).

Form

final test_form =fb.group({
  'multi_field': FormControl<List<String>>(validators: [Validators.required]),
});

Model

List<String> test_form_items=['item1', 'item2', 'item3'];

View

          ReactiveForm(
              formGroup: test_form,
              child: Padding(
                padding: const EdgeInsets.all(8.0),
                child: ReactiveDropdownSearchMultiSelection<String,String>(
                  validationMessages: {
                    ValidationMessage.required: (error) => 'Required!',
                  },
                  formControlName: 'multi_field',
                  items: test_form_items,
                ),
              ),
          ),
          SizedBox(height: 50,),
          OutlinedButton(
              onPressed: (){
                test_form.markAllAsTouched();
              },
              child: Text('Validate!'))

[vasilich6107]

Hi @leaderrr767
This is an issue with validator
joanpablo/reactive_forms#377

It does not handle empty lists and maps properly

[vasilich6107]

wait for joanpablo/reactive_forms#378

[vasilich6107]

as far as im casting null to [] i decided to cast back the value for consistency)
check reactive_dropdown_search 1.0.1