validateRequired function

String? Function(dynamic) validateRequired({
  1. String? failMessage,
  2. bool trim = true,
})

Returns error message if null or empty, null if valid

Implementation

String? Function(dynamic) validateRequired({String? failMessage, bool trim = true}) {
  return (dynamic value) {
    if (!isRequired(value, trim: trim)) {
      return failMessage ?? 'This field is required';
    }
    return null;
  };
}