Angular Material Autocomplete force selection

Question

In my angular 5 application I have some matAutocomplete, but I want to force the selection of oone of suggestions, so I am following this approach: stackblitz but for some reas

Answer 1

You can Create custom Validator , this will validate it perfectly tested code:

stateCtrl = new FormControl(null,[forbiddenNamesValidator(this.states)])


export function forbiddenNamesValidator(States: any[]): ValidatorFn {
  return (control: AbstractControl): { [key: string]: any } | null => {
    const index = States.findIndex(State=> {
      return (new RegExp('\^' + State.name + '\$')).test(control.value);
    });
    return index < 0 ? { 'forbiddenNames': { value: control.value } } : null;
  };
}