validateDto function

List<String> validateDto(Object dto)

takes dto and return list of faliure errors message

Implementation

List<String> validateDto(Object dto) {
  /// reflect the Dto to InstanceMirror
  final dtoMirror = reflect(dto);

  /// take out the Dto fields
  final fields = dtoMirror.type.declarations.values.whereType<VariableMirror>();

  /// errors is a list<String> which will contains the failed validation messages
  final errors = <String>[];

  /// loop for each field so if the the filed is annotated with
  /// any `QueenValidationRule` Object the loop will run the rule against the current
  /// field if is valid or is not annotate with any rules or annotate with other annotation
  /// it will skip it
  for (final field in fields) {
    /// `Iterable<QueenValidationRule>` which contains rules for this field
    final fieldRulesRef = field.metadata.where((r) => r.reflectee is TextValidationRule);
    final fieldRules = fieldRulesRef.map((r) => r.reflectee).toList().cast<TextValidationRule>();

    /// get the field value from the object
    final fieldValue = dtoMirror.getField(field.simpleName).reflectee;

    /// loop for every rule in the field rule and apply them
    if (fieldValue == null && fieldRules.whereType<IsOptional>().isNotEmpty) {
      // this is optional rule
      // and it is null value
      // so do not apply any rules
    } else if (fieldValue == null) {
      /// this felid is null and does not contain any value so it must fill
      final fieldName = MirrorSystem.getName(field.simpleName);
      for (final rule in fieldRules) {
        errors.add('$fieldName ${rule.defaultError}');
      }
    } else {
      // this field is not optional and contains value

      for (final rule in fieldRules) {
        /// if the validation fails add the field name and
        /// the validation message to the `errors` list
        if (!rule.isValid(fieldValue.toString())) {
          /// extract the field name
          final fieldName = MirrorSystem.getName(field.simpleName);

          /// add the error to the list
          errors.add('$fieldName ${rule.defaultError}');
        }
      }
    }
  }
  return errors;
}