Redux State Management in Flutter

Redux is a popular state management library that can be used in Flutter applications. The core idea behind Redux is to keep the state of the entire application in a single store and manage the state using a set of actions and reducers.

Here’s a brief overview of how to use Redux in a Flutter application:

Install the redux and flutter_redux packages: To use Redux in a Flutter application, you need to install the redux and flutter_redux packages. You can install these packages using the following command:

flutter pub add redux flutter_redux

Define the state: The state of the application is a representation of the data that needs to be stored and managed by Redux. You can define the state by creating a Dart class that represents the state. For example:

class AppState {
  final int count;

  AppState({this.count});
}

Define actions: Actions are used to change the state of the application. Actions are defined as Dart classes that extend the Redux.Action class. For example:

class IncrementCounterAction extends Redux.Action {
  final int value;

  IncrementCounterAction(this.value);
}

Define reducers: Reducers are functions that take the current state and an action, and return a new state based on the action. Reducers are defined as pure functions that don’t have side effects. For example:

AppState reducer(AppState state, dynamic action) {
  if (action is IncrementCounterAction) {
    return AppState(count: state.count + action.value);
  }

  return state;
}

Create the store: The store is the single source of truth in a Redux application. You can create the store by using the Redux.Store class. For example:

final store = Redux.Store<AppState>(
  reducer,
  initialState: AppState(count: 0),
);

Connect the widgets to the store: The widgets in a Flutter application can be connected to the store using the StoreProvider widget. The StoreProvider widget provides the store to the widgets that are nested within it. For example:

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return StoreProvider(
      store: store,
      child: MaterialApp(
        home: MyHomePage(),
      ),
    );
  }
}

Access the store from widgets: To access the state from a widget, you can use the StoreConnector widget. The StoreConnector widget takes a builder function that is called whenever the state changes. For example:

class MyHomePage extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Center(
        child: StoreConnector<AppState, int>(
          converter: (store) => store.state.count,
          builder: (context, count) {
            return Text('$count');
          },
        ),
      ),
    );
  }
}