Function setUpValidators

packages/forms/src/directives/shared.ts:186–214

(control: AbstractControl, dir: AbstractControlDirective)

 * @param dir Directive instance that contains validators to be setup.
 */
export function setUpValidators(control: AbstractControl, dir: AbstractControlDirective): void {
  const validators = getControlValidators(control);
  if (dir.validator !== null) {
    control.setValidators(mergeValidators<ValidatorFn>(validators, dir.validator));
  } else if (typeof validators === 'function') {
    // If sync validators are represented by a single validator function, we force the
    // `Validators.compose` call to happen by executing the `setValidators` function with
    // an array that contains that function. We need this to avoid possible discrepancies in
    // validators behavior, so sync validators are always processed by the `Validators.compose`.
    // Note: we should consider moving this logic inside the `setValidators` function itself, so we
    // have consistent behavior on AbstractControl API level. The same applies to the async
    // validators logic below.
    control.setValidators([validators]);
  }

  const asyncValidators = getControlAsyncValidators(control);
  if (dir.asyncValidator !== null) {
    control.setAsyncValidators(
      mergeValidators<AsyncValidatorFn>(asyncValidators, dir.asyncValidator),
    );
  } else if (typeof asyncValidators === 'function') {
    control.setAsyncValidators([asyncValidators]);
  }

  // Re-run validation when validator binding changes, e.g. minlength=3 -> minlength=4
  const onValidatorChange = () => control.updateValueAndValidity();
  registerOnValidatorChange<ValidatorFn>(dir._rawValidators, onValidatorChange);
  registerOnValidatorChange<AsyncValidatorFn>(dir._rawAsyncValidators, onValidatorChange);
}

/**
 * Cleans up sync and async directive validators on provided form control.