HydratedMobX

A Flutter package that automatically persists and restores MobX stores. Built to work with Flutter's state management solution MobX.

This package uses some code from hydrated_bloc by Felix Angelov, which is licensed under the MIT License. We extend our gratitude to the original authors for their work.

Features

• Automatically persists and restores MobX stores
• Supports encryption for secure storage
• Works on all platforms (iOS, Android, Web, Linux, macOS, Windows)
• Built on top of Hive for fast and efficient storage
• Simple and intuitive API

Getting started

Add the package to your pubspec.yaml:

dependencies:
  hydrated_mobx: ^1.1.3

Usage

1. Initialize HydratedMobX in your main.dart:

import 'package:flutter/foundation.dart';
import 'package:flutter/material.dart';
import 'package:hydrated_mobx/hydrated_mobx.dart';
import 'package:path_provider/path_provider.dart';

Future<void> main() async {
  WidgetsFlutterBinding.ensureInitialized();
  final appDocumentDir = await getApplicationDocumentsDirectory();
  HydratedMobX.storage = await HydratedStorage.build(
    storageDirectory: HydratedStorageDirectory(appDocumentDir.path),
  );
  runApp(App());
}

2. Create a hydrated store:

import 'package:mobx/mobx.dart';
import 'package:hydrated_mobx/hydrated_mobx.dart';

part 'counter_store.g.dart';

class CounterStore = _CounterStore with _$CounterStore;

abstract class _CounterStore extends HydratedMobX with Store {
  @observable
  int count = 0;

  @action
  void increment() => count++;

  @override
  Map<String, dynamic>? toJson() => {'count': count};

  @override
  void fromJson(Map<String, dynamic> json) {
    count = json['count'] as int;
  }
}

Overriding the storage key (per-instance id)

When you have multiple instances of the same store (e.g. one per meeting or per user), pass the id to super(storeId: ...) so hydration uses the correct key. This works with dependency injection (e.g. injectable):

abstract class _MeetingStoreBase extends HydratedMobX with Store {
  _MeetingStoreBase(
    DioService dioService,
    MeetingsStore meetingsStore,
    @factoryParam String meetingId,
  ) : _meetingId = meetingId,
      super(storeId: meetingId);

  final String _meetingId;

  @override
  String get id => _meetingId;
  // ...
}

See the example app’s KeyedCounterStore for a minimal example.

Type-safe fromJson / toJson with HydratedJson

To avoid manual type checks and try/catch in fromJson/toJson, use the HydratedJson helpers:

import 'package:hydrated_mobx/hydrated_mobx.dart';
import 'package:mobx/mobx.dart';

@override
void fromJson(Map<String, dynamic> json) {
  _meetings = HydratedJson.readList(
    json,
    'meetings',
    MeetingDto.fromJson,
  ).asObservable();
  _meta = HydratedJson.readObject(json, 'meta', MetaDto.fromJson) ??
      MetaDto(take: 20);
}

@override
Map<String, dynamic> toJson() => {
  'meetings': HydratedJson.writeList(_meetings, (e) => e.toJson()),
  'meta': _meta.toJson(),
};

Available helpers: readList, readObject, readString, readInt, readDouble, readBool, writeList. They return safe defaults (e.g. empty list, 0, null) when the key is missing or the value has the wrong type.

Additional information

• For more information about MobX, visit the MobX documentation
• For issues and feature requests, please visit the GitHub repository
• Contributions are welcome! Feel free to submit pull requests or open issues