flutter_state_management 0.4.0

A collection of helper classes to make the use of ChangeNotifier easier for state management

Flutter State Management

This is not a new state management solution. It is just a couple of utility classes to make it easier to use the Flutter framework's built-in ChangeNotifier and Listenable.

Features

• No learning curve if you already know Flutter
• Simple package based on ChangeNotifier (No bloatware)

Usage

Create your model class

class Counter extends StateNotifier<int, Error> {
  Counter() : super(const Loaded(data: 0));

  void increment() async {
    state = Loading(data: data);

    await Future.delayed(const Duration(seconds: 2));

    if (data > 20) {
      state = Failed(error: StateError('greater than 20'), data: data);
    } else {
      state = Loaded(data: data + 1);
    }
  }
}

Or if you want the state to persist across restarts

class Counter extends PersistedStateNotifier<int, int> {
  Counter() : super(IsarKeyValue(), startState: 0);

  void increment() async {
    persistedState = Loading(data: data);

    await Future.delayed(const Duration(seconds: 2));

    if (data > 20) {
      persistedState = Failed(error: StateError('greater than 20'), data: data);
    } else {
      persistedState = Loaded(data: data + 1);
    }
  }
}

Use builder to handle state changes in the UI

final counter = Counter();

counter.builder(
  onLoaded: (context, data) => Text(data.toString()),
),

Or convert your existing StatelessWidget to RStatelessWidget, and StatefulWidget to RStatefulWidget and just watch the model inside the build method

class CounterText extends RStatelessWidget {
  @override
  Widget build(BuildContext context) {
    counter.watch(context); // watch must be called inside the build method
    return Text(data.toString());
  }
}