Errors and localization

Localization

ZodArt provides various localized error messages for build in parsing and validations. Default language is set to English, to change it use ZLocalizationContext.current

Currently supported languages are:

• English
• Czech
• Japanese

Custom error handling

ZodArt contains various helpers for error handling, see documentation for more info

Example

See full example.

import 'package:zodart/zodart.dart';

part 'localization.zodart.dart';
part 'localization.zodart.type.dart';

/// Schema defined using ZodArt (generates [Person] class)
@ZodArt.generateNewClass(outputClassName: 'Person')
abstract class PersonSchema {
  /// Validates that:
  /// - `firstName` is from 1 to 20 characters long
  /// - `lastName` is from 1 to 30 characters long
  /// - `age` is ≥ 0 (optional)
  static final schema = (
    firstName: ZString().min(1).max(20),
    lastName: ZString().min(1).max(30),
    age: ZInt().optional().min(0),
  );

  static const z = _PersonSchemaUtils();
  static final ZObject<Person> zObject = z.zObject;
}

void main() {
  final result = PersonSchema.zObject.parse({'firstName': '', 'lastName': 'Art', 'age': -1});

  // Prints an English error message summary (default)
  print(result.issueSummary);

  // Change localization to Czech (see other supported languages)
  ZLocalizationContext.current = ZIssueLocalizationService(Language.cs);

  // Prints error message summary in Czech
  print(result.issueSummary);

  // To get the individual localized message strings
  final messages = result.issueMessages;
  print(messages);

  // Each issue is represented by a `ZIssue` instance
  final zIssues = result.rawIssues;

  // Custom translation logic using pattern matching (Dart 3+)
  final customMessages =
      zIssues?.map((zIssue) {
        return switch (zIssue) {
          ZIssueMinNotMet(:final min, :final val) => 'My custom message: $val is lower than $min!',
          _ => 'My custom message: Other problem',
        };
      }) ??
      [];

  print('\nCustom messages:');
  print(customMessages);

  // To get error message summary only for the 'age' property
  print('\nMessage for the age field:');
  print(result.getSummaryFor(PersonSchema.z.props.age.name));
}