Hydrated | A BehaviorSubject for Flutter with Automatic Persist

Hydrated provides a Subject that automatically persists to Flutter's local storage and hydrates on creation!

Easy to consume

All values are persisted with shared_preferences and restored with automatic hydration.

final count$ = HydratedSubject<int>("count", seedValue: 0);

/// count$ will automagically be hydrated with 42 next time it is created
count$.add(42);

Ready for BLoC

class HydratedBloc {
  final _count$ = HydratedSubject<int>("count", seedValue: 0);

  ValueObservable<int> get count$ => _count$.stream;
  Sink<int> get setCount => _count$.sink;

  dispose() {
    _count$.close();
  }
}

Supports simple types and serialized classes

We support all shared_preferences types.

• int
• double
• bool
• String
• List<String>

final count$ = HydratedSubject<int>("count");

We also support serialized classes with hydrate and persist arguments.

final user$ = HydratedSubject<User>(
  "user",
  hydrate: (String s) => User.fromJSON(s),
  persist: (User user) => user.toJSON(),
);

Reliable

Hydrated is mock tested with all supported types and is dogfooded by its creator.

Demo

Use this package as a library

Depend on it

Run this command:

With Flutter:

 $ flutter pub add hydrated

This will add a line like this to your package's pubspec.yaml (and run an implicit dart pub get):

dependencies:
  hydrated: ^2.0.1

Alternatively, your editor might support flutter pub get. Check the docs for your editor to learn more.

Import it

Now in your Dart code, you can use:

import 'package:hydrated/hydrated.dart';

example/lib/main.dart

import 'package:flutter/material.dart';
import 'package:hydrated/hydrated.dart';

void main() => runApp(MyApp());

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Hydrated Demo',
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: MyHomePage(title: 'Hydrated Demo'),
    );
  }
}

class MyHomePage extends StatelessWidget {
  final String _title;
  final _count = HydratedSubject<int>("count", seedValue: 0);

  MyHomePage({
    Key? key,
    required String title,
  })  : _title = title,
        super(key: key);

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text(this._title),
      ),
      body: Center(
        child: StreamBuilder<int>(
          stream: _count,
          initialData: _count.value,
          builder: (context, snap) => Column(
            mainAxisAlignment: MainAxisAlignment.center,
            children: [
              Text('You have pushed the button this many times:'),
              Text(
                '${snap.data}',
                style: Theme.of(context).textTheme.headline4,
              ),
            ],
          ),
        ),
      ),
      floatingActionButton: FloatingActionButton(
        onPressed: _incrementCounter,
        tooltip: 'Increment',
        child: Icon(Icons.add),
      ),
    );
  }

  void _incrementCounter() {
    _count.value++;
  }

  void dispose() {
    _count.close();
  }
}

Original developer

hydrated was originally developed by @lukepighetti.