angular formcontrol have required validator code example
Example 1: 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;
};
Example 2: angular check if control has required validator
import { AbstractControl } from '@angular/forms';
export const isControlRequired = (control: AbstractControl): boolean => {
if (!control) {
return false;
}
if (control.validator) {
const validator = control.validator({} as AbstractControl);
if (validator && validator.required) {
return true;
}
}
return false;
};