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');
},
),
),
);
}
}