in angular/src/app/app-validators/must-match.validator.ts [4:21]
export function MustMatchValidator(controlName: string, matchingControlName: string) {
return (formGroup: FormGroup) => {
const control = formGroup.controls[controlName];
const matchingControl = formGroup.controls[matchingControlName];
if (matchingControl.errors && !matchingControl.errors.mustMatch) {
// return if another validator has already found an error on the matchingControl
return;
}
// set error on matchingControl if validation fails
if (control.value !== matchingControl.value) {
matchingControl.setErrors({ mustMatch: true });
} else {
matchingControl.setErrors(null);
}
};
}