required<T> static method

FormFieldValidator<T> required<T>({
  1. String? errorText,
})

Implementation

static FormFieldValidator<T> required<T>({String? errorText}) {
  return (T? valueCandidate) {
    if (valueCandidate == null ||
        (valueCandidate is String && valueCandidate.trim().isEmpty) ||
        (valueCandidate is Iterable && valueCandidate.isEmpty) ||
        (valueCandidate is Map && valueCandidate.isEmpty)) {
      return errorText ?? BasicFormValidatorMessageError().required;
    }
    return null;
  };
}