angular custom directive validator code example
Example: how to add validator to formgroup
this.myForm = this.formBuilder.group({
myControl1: this.defaultValue,
myControl2: this.defaultValue
});
debugger
this.myForm.setValidators(this.comparisonValidator())
}
public comparisonValidator() : ValidatorFn{
return (group: FormGroup): ValidationErrors => {
const control1 = group.controls['myControl1'];
const control2 = group.controls['myControl2'];
if (control1.value !== control2.value) {
control2.setErrors({notEquivalent: true});
} else {
control2.setErrors(null);
}
return;
};