dox_validation 3.0.0-alpha.5

Typed input for Dart. DTO classes with generated checks, fluent schemas like Zod, JSON Schema export and the Standard Schema interface.

dox_validation

Typed input for Dart: DTO classes with generated checks, and fluent schemas like Zod.

Part of Dox, a web backend framework for Dart, like Laravel. Source code: github.com/dartondox/dox.

Install

In a Dox app you do not add it. dox_core exports it. Outside Dox:

dart pub add dox_validation
dart pub add dev:dox_builder dev:build_runner

Dox 3.x is in alpha (3.0.0-alpha.4). The API can still change before the stable release.

Use it

A DTO: a class with @Dto() and rule annotations. dox_builder writes the checks.

import 'package:dox_validation/dox_validation.dart';

part 'create_user.dto.g.dart';

@Dto()
class CreateUser {
  @Length(min: 3, max: 50)
  @Trim()
  final String name;

  @Email()
  final String email;

  const CreateUser({required this.name, required this.email});

  static const DtoSchema<CreateUser> schema = $CreateUserDto;
}

Run dart run build_runner build. Then:

ParseResult<CreateUser> result = await CreateUser.schema.safeValidateMap(input);
if (!result.success) {
  print(result.errors); // {'email': 'The email is not a valid email'}
}

A fluent schema, for input you only know at runtime:

final ObjectSchema createUser = v.object(<String, Schema<Object?>>{
  'name': v.string().trim().min(3).max(50),
  'email': v.string().email(),
  'age': v.coerce.int().min(18).optional(),
});

Map<String, dynamic> data = createUser.parse(input); // throws ValidationException

Features

• All problems come back at once, each with a path, a code and a message.
• Messages can change per rule, per call or for the whole app (for other languages).
• v.coerce turns query and form text into numbers, booleans and dates.
• Async checks with refineAsync and parseAsync.
• JSON Schema (draft 2020-12) with toJsonSchema(). OpenAPI uses it.
• Every schema implements the Standard Schema interface.
• No dependencies.

Documentation

• Validation package
• Validation guide and rules reference
• API reference

License

MIT. See LICENSE.