required<T> static method

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

Implementation

static FormFieldValidator<T> required<T>({
  required String message,
}) =>
    (T? value) {
      if (value == null) return message;
      if (value is String && value.isEmpty) return message;
      if (value is List && value.isEmpty) return message;
      if (value is Map && value.isEmpty) return message;
      return null;
    };