janus 0.1.0

Janus simplifies local storage of data with encryption

Janus provide an easy API to persist models in the local storage with encryption.

CAPTION: Not working in Flutter Web

Features

Janus is a quick serializer for local storage of data models. Perfect for storing your app preferences or other data of interest. By default, the storage is made with encryption.

Getting started

Using this package is pretty straightforward. The following examples will store some preferences in memory:

    class Preferences extends Janus {
     
        const Preferences(
            {this.token = '', 
            this.lightTheme = true, 
            this.fontSize = 15.0,
            this.firstLoading = true,
            this.shoppingCartProducts = const []})
             : super({cypher: true});
    }

        final String token;
        final bool lightTheme;
        final double fontSize;
        final bool firstLoading;
        final List<String> shoppingCartProducts = [];

        Map<String,dynamic> toMap() => {
            'token': token,
            'lightTeme': lightTheme,
            'fontSize': fontSize,
            'firstLoading': firstLoading,
            'shoopingCartProducts': shoppingCartProducts
        };

        factory Preferences.fromMap(Map<String,dynamic> map) 
            => Preferences(
                token: map['token'],
                lightTheme: map['lightTheme'],
                fontSize: map['fontSize'],
                firstLoading: map['firstLoading'],
                shoppingCartProducts: map['shoppingCartProducts']
            );
    
    void main()async{
        final preferences = Preferences();
        final data = {
            'token': 'TOKEN',
            'lightTeme': false,
            'fontSize': 22.2,
            'firstLoading': false,
            'shoopingCartProducts': ['Uuid1','Uuid2','Uuid3']
        }

        await preferences.save(data);
        final loadedPreferences = Preferences.fromMap(await preferences.load());
    }

Usage

Personally, it's preferable not to extend directly Janus to your data model. Instead of that, try to split you data layer in three parts:

• models
• apis
• repositories

The apis folder will bear the classes that will provide access to your webservices or local storage. Here will may be the classes that can extends Janus.

//apis/user_model.dart
class User{
    final String id;
    final String email;

    Map<String,dynamic> toMap() => {
        'id': id,
        'email': email
    };

    factory User.fromMap(Map<String,dynamic> map) => User(id: map['id'], email: map['email']);
}

//apis/user_storage.dart
class UserStorage extends Janus{
    const UserStorage() : super({cypher:true});
    //janus will provide the load and save methods!

    //obviusly, you can register any needed method here
}

//repositories/user_storage_repository.dart
class UserStorageRepository{

    final api = UserStorage();

    //this is only an example
    Future<void> save(User user)async{
        await api.save(user.toMap());
    }
    Future<User> load() async {
        return await User.fromMap(await api.load());
    }

}

//Now you can use the repository to persist the user in you local memory or to load it from local.
final userRepository = UserStorageRepository();
final User user = User(id: 'uuid', email: '[e-mail]');
await userRepository.save(user);

final loadedUser = await userRepository.load();

Additional information