forward2<U, E0 extends Object, E1 extends Object> method

Result<U, Errors2<E0, E1>> forward2<U, E0 extends Object, E1 extends Object>({ U success(T r)?, Object failure(Object err)?, })

Allows to forward and transform successful and failed results. If operation was successful, calls success callback and returns successful result with transformed data. If operation failed, calls failure callback for each error and returns failed result with transformed errors. Example:

Errors2<Unauthorized, ValidationError> httpPost(String path, Object data) {
  ...
}

AsyncResult<AuthToken, Errors2<InvalidCredentials, EmailNotConfirmed>> login(String login, String password) {
  final response = httpPost('/auth/login', {'login': login, 'password': password});
  return response.forward2(
    success: (r) => AuthToken.parse(r.data),
    failure: (e) => switch (e) {
      (ValidationError e) when e.code == 'email-not-confirmed' => EmailNotConfirmed(),
      (Unauthorized _) => InvalidCredentials(),
      _ => e
    });
}

Implementation

Result<U, Errors2<E0, E1>> forward2<U, E0 extends Object, E1 extends Object>({
  U Function(T r)? success,
  Object Function(Object err)? failure,
}) {
  final expected = Errors2<E0, E1>();

  return _forward(success: success, failure: failure, expected: expected);
}