Function pickAsyncValidators

packages/forms/src/model/abstract_model.ts:209–219

(
  asyncValidator?: AsyncValidatorFn | AsyncValidatorFn[] | null,
  validatorOrOpts?: ValidatorFn | ValidatorFn[] | AbstractControlOptions | null,
)

 * Gets async validators from either an options object or given validators.
 */
export function pickAsyncValidators(
  asyncValidator?: AsyncValidatorFn | AsyncValidatorFn[] | null,
  validatorOrOpts?: ValidatorFn | ValidatorFn[] | AbstractControlOptions | null,
): AsyncValidatorFn | AsyncValidatorFn[] | null {
  if (typeof ngDevMode === 'undefined' || ngDevMode) {
    if (isOptionsObj(validatorOrOpts) && asyncValidator) {
      console.warn(asyncValidatorsDroppedWithOptsWarning);
    }
  }
  return (isOptionsObj(validatorOrOpts) ? validatorOrOpts.asyncValidators : asyncValidator) || null;
}

/**
 * Creates async validator function by combining provided async validators.