GeezerVison

    
      class SelectMultipleControlValueAccessor extends BuiltInControlValueAccessor implements ControlValueAccessor {}
    
    

The ControlValueAccessor for writing multi-select control values and listening to multi-select control changes. The value accessor is used by the FormControlDirective, FormControlName, and NgModel directives.

Using a multi-select control

The follow example shows you how to use a multi-select control with a reactive form.

const countryControl = new FormControl();

<select multiple name="countries" [formControl]="countryControl">
  @for(country of countries; track $index) {
     <option [ngValue]="country">{{ country.name }}</option>
  }
</select>

Customizing option selection

To customize the default option comparison algorithm, <select> supports compareWith input. See the SelectControlValueAccessor for usage.