When using Clean Architecture in a Flutter app, you can implement state management in the Presentation Layer . Here is a step-by-step guide on how to integrate it into your app: provider provider
1. Structure your application into layers
Data Layer: responsible for receiving data from external sources (API, databases, etc.).
Domain Layer: contains business logic, entities and use cases.
Presentation Layer: Contains UI components and state management.
2. Set up the dependencyprovider
Add pubspec.yamldependency to the file:
dependencies:
provider: ^6.0.0
3. Create classes to manage state
In the presentation layer, create classes that inherit from ChangeNotifierthat will manage state and interact with the domain layer.
class ExampleViewModel extends ChangeNotifier {
final GetDataUseCase _getDataUseCase;
ExampleViewModel(this._getDataUseCase);
String _data;
bool _isLoading = false;
String get data => _data;
bool get isLoading => _isLoading;
Future<void> fetchData() async {
_isLoading = true;
notifyListeners();
_data = await _getDataUseCase.execute();
_isLoading = false;
notifyListeners();
}
}
4. Set up Dependency Injection
Use a package get_itfor dependency injection.
final getIt = GetIt.instance;
void setup() {
// ??????????? use cases
getIt.registerLazySingleton<GetDataUseCase>(() => GetDataUseCaseImpl());
// ??????????? ViewModel
getIt.registerFactory<ExampleViewModel>(() => ExampleViewModel(getIt<GetDataUseCase>()));
}
5. Provide providers in the main widget
Use main.dartto MultiProviderexpose your ViewModels to the entire widget tree.
void main() {
setup();
runApp(
MultiProvider(
providers: [
ChangeNotifierProvider(
create: (_) => getIt<ExampleViewModel>(),
),
],
child: MyApp(),
),
);
}
6. Use ViewModel in widgets
In your UI components, get data from the ViewModel.
class ExamplePage extends StatelessWidget {
@override
Widget build(BuildContext context) {
final viewModel = Provider.of<ExampleViewModel>(context);
return Scaffold(
appBar: AppBar(title: Text('??????')),
body: viewModel.isLoading
? Center(child: CircularProgressIndicator())
: Center(child: Text(viewModel.data ?? '??? ??????')),
floatingActionButton: FloatingActionButton(
onPressed: viewModel.fetchData,
child: Icon(Icons.download),
),
);
}
}
7. Follow the principles of Clean Architecture
The presentation layer interacts with the domain layer through use cases.
The domain layer is independent and does not depend on other layers.
The data layer implements interfaces from the domain layer and provides data.
8. Share the responsibility
Keep business logic in the domain layer.
Use ViewModel to manage state and interact with use cases.
UI components should be responsible only for display.
9. Testing
By clearly separating layers and using DI, you can easily write unit tests for each layer.
Thus, implementing provider Clean Architecture into your application will allow you to create a scalable and maintainable application with clear separation of concerns
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