Get validators present in FormGroup/FormControl

Question

I\'m using Material 2 in my app, but in this question I want to solve a problem specifically with Input.

As you can see in API Reference there\'s a

Answer 1

This answer is a continuation of @joh04667's. They wrote:

public hasValidator(control: string, validator: string): boolean {
  return !!this.myForm.controls[control].validators(control).hasOwnProperty(validator);
 // returns true if control has the validator
}

However there is no AbstractControls.validators() method. I'm assuming AbstractControls.validator() was meant.

The hasValidator() method only works for validators that 'fail' (eg. a required validator on a control with the value '' (empty)). Since if they pass they return null. A way around this would be to set the value so that it always fails and restore that afterwards.

public hasValidator(control: string, validator: string): boolean {
    let control: AbstractControl = this.myForm.controls[control];
    let lastValue: any = control.value;
    switch(validator) {
        case 'required':
            control.setValue('');  // as is appropriate for the control
        case 'pattern':
            control.setValue('3'); // given you have knowledge of what the pattern is - say its '\d\d\d'
        ....
    }
    let hasValidator: boolean = !!control.validator(control).hasOwnProperty(validator);

    control.setValue(lastValue);
    return hasValidator;
}

And this is pretty horrible. It begs the question - Why is there no AbstractControl.getValidators(): ValidatorFn[]|null?

What is the motivation in hiding this? Perhaps they are worried someone might put in their code:

...
secretPassword: ['', [Validators.pattern('fjdfjafj734738&UERUEIOJDFDJj')]
...