onValidate method

Implementation

@override
ValidationResult onValidate(FieldController<T> controller) {
  final value = controller.value;
  bool isValid = true;
  if (controller.value != null) {
    if (value is String) {
      isValid = value.length <= maxLength;
    } else if (value is List) {
      isValid = value.length <= maxLength;
    } else if (value is Map) {
      isValid = value.length <= maxLength;
    } else if (value is Set) {
      isValid = value.length <= maxLength;
    } else {
      isValid = false;
    }
  }
  return ValidationResult(
    key: GenericValidators.maxLength.name,
    message: message,
    isValid: isValid,
  );
}