easy_validation 0.0.3

A new Flutter package project for model validation.

Easy Validation

EasyValidation provides many validators for Flutter, based on Dart plugin Respectable.

Get started

First, you need to add the following dependencies to your 'pubspec.yaml':

dependencies:
  reflectable: any
  build_runner: any
  easy_validation: any

How to use validators and validate a model

Here is a simple usage example. Note that a lot of examples are available in unit test file test/easy_validation_test.dart.

How to define a class model with validation:

import 'package:easy_validation/easy_validation.dart';

@easyValidation
class MyModel {
  MyModel(this.firstname, this.lastname, this.gender, this.birthday, this.dateOfDeath);
  
  @Required(error: 'Firstname is required')
  @StringLength(min: 3, max: 32, error: 'Firstname must have between 3 and 32 characters')
  final String firstname;
  
  @Required(error: 'Lastname is required')
  @StringLength(min: 3, max: 32, error: 'Lastname must have between 3 and 32 characters')
  final String lastname;

  @Required(error: 'Gender is required')
  @StringLength(min: 1, max: 1, error: 'Gender must have 1 character')
  final String gender;

  @Required(error: 'Birthday is requried')
  @DateTimeRange(min: '1900-01-01', max: null, error: 'Birthday must be betwwen 1900/01/01 and infinity')
  final DateTime birthday;

  @DateTimeRange(min: '1900-01-01', max: null, error: 'DateOfDeath must be betwwen 1900/01/01 and infinity')
  @GreaterOrEqualTo(propertyName: 'birthday', error: 'DateOfDeath must be greater than Birthday')
  final DateTime dateOfDeath;
}

Each time you add a validator and each time you update your model class, you must regenerate a mapping file of your models and validators. If this file is not generated and update after any change, EasyValidation won't work !

Use this command line to get the file to get a new file named *.reflectable.dart into a flutter package project.

> flutter packages pub run build_runner build

Use this command line to get the file to get a new file named *.reflectable.dart into a flutter application project.

> flutter pub run build_runner build

How to validate a model:

• Import the generated mapping file.
• Call initializeReflectable funtion.

import 'package:easy_validation/easy_validation.dart';
import 'package:*.reflectable.dart';

initializeReflectable();

MyModel tester = new MyModel('Maxime', 'AUBRY', 'M', DateTime.parse('1986-12-22'), null);
bool isValid = ModelState.isValid<MyModel>(tester);

if (isValid) {
  // do stuff...
} else {
  print(ModelState.errors);
}

Practice usage for Flutter with Blocs:

Here is the authentication_form.dart file:

class AuthenticationForm extends StatefulWidget {
  @override
  _AuthenticationFormState createState() => _AuthenticationFormState();
}

class _AuthenticationFormState extends State<AuthenticationForm> {
  final TextEditingController _emailController = TextEditingController();
  final TextEditingController _passwordController = TextEditingController();

  AuthenticationFormBloc _authenticationFormBloc;

  @override
  void initState() {
    super.initState();
    _authenticationFormBloc = BlocProvider.of<AuthenticationFormBloc>(context);
    _emailController.addListener(_onEmailChanged);
    _passwordController.addListener(_onPasswordChanged);
  }

  @override
  void dispose() {
    _emailController.dispose();
    _passwordController.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext pageContext) {
    return MultiBlocListener(
      listeners: [
        // ...
      ],
      child: BlocBuilder<AuthenticationFormBloc, AuthenticationFormState>(
        builder: (BuildContext context, AuthenticationFormState state) {
          return Form(
            child: Padding(
              padding: EdgeInsets.all(15),
              child: Column(
                mainAxisAlignment: MainAxisAlignment.start,
                crossAxisAlignment: CrossAxisAlignment.stretch,
                children: <Widget>
                  EmailInput(controller: _emailController),
                  PasswordInput(controller: _passwordController),
                ],
              ),
            ),
          );
        },
      ),
    );
  }

  // Events
  void _onEmailChanged() {
    _authenticationFormBloc
        .dispatch(EmailChangedEvent(email: _emailController.text));
  }

  void _onPasswordChanged() {
    _authenticationFormBloc
        .dispatch(PasswordChangedEvent(password: _passwordController.text));
  }
}

Here is the email_input.dart:

class PasswordInput extends StatelessWidget {
  PasswordInput({
    @required this.controller,
  });

  final TextEditingController controller;

  @override
  Widget build(BuildContext context) {
    final AuthenticationFormBloc _authenticationFormBloc =
        BlocProvider.of<AuthenticationFormBloc>(context);

    return BlocBuilder<AuthenticationFormBloc, AuthenticationFormState>(
      bloc: _authenticationFormBloc,
      builder: (BuildContext context, AuthenticationFormState state) {
        return TextFormField(
          decoration: InputDecoration(
            icon: Icon(
              Icons.lock,
              color: Colors.grey,
            ),
            suffixIcon: IconButton(
              icon: Icon(
                Icons.info,
                color: Colors.grey,
              ),
            ),
            labelText: 'Password',
            labelStyle: TextStyle(color: Colors.grey),
          ),
          controller: controller,
          obscureText: true,
          autovalidate: true,
          autocorrect: false,
          textInputAction: TextInputAction.done,
          keyboardType: TextInputType.text,
          validator: (String value) {
            if (state.errors.containsKey('password'))
              return state.errors['password'];
            return null;
          },
        );
      },
    );
  }
}

Here is the authentication_model.dart file:

@easyValidator
class AuthenticationModel {
  AuthenticationModel(
    this.email,
    this.password,
  );

  @Required(error: 'Email is required')
  String email;

  @Required(error: 'Password is required')
  @MembershipPassword(
      minLength: 8,
      maxLength: 16,
      includesAlphabeticalCharacters: true,
      includesUppercaseCharacters: true,
      includesNumericalCharacters: true,
      includesSpecialCharacters: true,
      error: 'Invalid password')
  String password;
}

Here is the authentication_form_bloc.dart:

class AuthenticationFormBloc
    extends Bloc<AuthenticationFormEvent, AuthenticationFormState> {
  @override
  AuthenticationFormState get initialState => AuthenticationFormState.initial();

  @override
  Stream<AuthenticationFormState> mapEventToState(
    AuthenticationFormEvent event,
  ) async* {
    if (event is PasswordChangedEvent)
      yield* _onPasswordChanged(event.password);
  }

  Stream<AuthenticationFormState> _onPasswordChanged(String password) async* {
    yield currentState.copyWith(password: password);
  }
}

Here is the authentication_form_event.dart file:

@immutable
abstract class AuthenticationFormEvent extends Equatable {
  AuthenticationFormEvent([List props = const []]) : super(props);
}

class PasswordChangedEvent extends AuthenticationFormEvent {
  final String password;

  PasswordChangedEvent({@required this.password}) : super([password]);

  @override
  String toString() => 'PasswordChangedEvent { password: $password }';
}

Here is the authentication_form_state.dart file:

import 'dart:convert';

import 'package:easy_validation/easy_validation.dart';
import 'package:equatable/equatable.dart';
import 'package:greenworld/main.reflectable.dart';
import 'package:greenworld/models/authentication_model.dart';
import 'package:meta/meta.dart';

@immutable
class AuthenticationFormState extends Equatable {
  final String email;
  final String password;
  final Map<String, ValidationError> errors = Map<String, ValidationError>();
  final bool isFormValid;

  AuthenticationFormState({
    @required this.email,
    @required this.password,
    Map<String, ValidationError> errors,
    @required this.isFormValid,
  }) : super([
          email,
          password,
          isFormValid,
        ]) {
    this.errors.addAll(errors);
  }

  bool _validate(AuthenticationModel model, Map<String, ValidationError> _errors) {
    initializeReflectable();
    bool _isFormValid = ModelState.isValid<AuthenticationModel>(model);

    if (_isFormValid) {
      print('form is valid');
      print(json.encode(model));
      _errors.clear();
    } else {
      print('Form is not valid');
      print(json.encode(model));
      _errors.addAll(ModelState.errors ?? Map<String, ValidationError>());
    }

    return _isFormValid;
  }

  factory AuthenticationFormState.initial() {
    return AuthenticationFormState(
      email: '',
      password: '',
      errors: Map<String, ValidationError>(),
      isFormValid: false,
    );
  }

  AuthenticationFormState copyWith({
    String email,
    String password,
    String retypePassword,
  }) {
    AuthenticationModel model = AuthenticationModel(
      email ?? this.email,
      password ?? this.password,
    );
    Map<String, ValidationError> _errors = Map<String, ValidationError>();
    bool _isFormValid = _validate(model, _errors);

    return AuthenticationFormState(
      email: email ?? this.email,
      password: password ?? this.password,
      errors: _errors,
      isFormValid: _isFormValid,
    );
  }

  @override
  String toString() {
    return '''AuthenticationFormState {
      email: $email,
      password: $password,
      errors: $errors,
      isFormValid: $isFormValid,
    }''';
  }
}

Feature requests and bug reports

Please file feature requests and bugs using the github issue tracker for this repository.