How to pass another value to form validation method?

Question

I have created the form group as below

import { setPwd } from './validators';

@Component({
....
export class pwdComp {
     ...

     this.userFormPassword = this.fb.group({
       'password': ['', [ setPwd ]]
     });

In my another ts file has the setPwd method

export function setPwd(c: FormControl) {
  const SINGLE_LETTER_NUMERAL = /^\=\?$/;
  return SINGLE_LETTER_NUMERAL.test(c.value) ? null : {
    pwd: {
      valid: false
    }
  };
}

The above script is working fine. But now my new scenario is I want to pass the pattern attribute to the setPwd method, So I tried as below

this.userFormPassword = this.fb.group({
    'password': ['', [ setPwd('**') ]]
});

and the setPwd method is

export function setPwd(c: FormControl, newPattern) {

But it is throwing the error. How to pass the extra value to the external function.

reference article : https://dzone.com/articles/how-to-create-custom-validators-in-angular — Ubiquitous Developers, Feb 28 '19 at 09:12
or duplication of : https://stackoverflow.com/questions/36756159/angular-2-custom-validator-with-parameters — Ubiquitous Developers, Feb 28 '19 at 09:12

score 1 · Accepted Answer · answered Feb 28 '19 at 09:13

1

You should change your function like below

export function setPwd(pattern: RegExp): ValidatorFn {
  return (control: AbstractControl): {[key: string]: any} | null => {
    const forbidden = pattern.test(control.value);
    return forbidden ? {'pwd': {value: control.value}} : null;
  };
}

this.userFormPassword = this.fb.group({
    'password': ['', setPwd('**') ]
});

answered Feb 28 '19 at 09:13

Nithya Rajan

4,722
19
30

Thanks for your answer but I am getting `cannot read property 'controls' of undefined` error. – mkHun Feb 28 '19 at 09:32
1

is it conrols of undefined or control of undefined? – Nithya Rajan Feb 28 '19 at 09:36
1

have you imported ValidatorFn and AbstractControl from angular ? – Nithya Rajan Feb 28 '19 at 09:39

How to pass another value to form validation method?

1 Answers1