Flutter Clean Architecture is the industry standard for building scalable, testable, and maintainable mobile apps. This guide walks you through a production-ready implementation for 2026.
**
What Is Clean Architecture?
**
Three concentric layers where dependencies point inward only:
- *Presentation *— Widgets, pages, state management (Bloc/GetX)
- *Domain *— Pure Dart: entities, use cases, repository interfaces
- *Data *— Repository implementations, models, remote/local data sources
**Recommended Folder Structure
**
CODE
lib/
├── core/
│ ├── errors/
│ │ ├── exceptions.dart
│ │ └── failures.dart
│ └── usecases/usecase.dart
│
└── features/
└── auth/
├── data/
│ ├── datasources/auth_remote_datasource.dart
│ ├── models/user_model.dart
│ └── repositories/auth_repository_impl.dart
├── domain/
│ ├── entities/user_entity.dart
│ ├── repositories/auth_repository.dart
│ └── usecases/login_usecase.dart
└── presentation/
├── bloc/
│ ├── auth_bloc.dart
│ ├── auth_event.dart
│ └── auth_state.dart
└── pages/login_page.dart
**
Domain Layer — The Core
**
CODE
// entity — pure Dart, no packages
class UserEntity {
final String id;
final String email;
final String displayName;
const UserEntity({required this.id, required this.email, required this.displayName});
}
// repository interface
abstract class AuthRepository {
Future<Either<Failure, UserEntity>> login({
required String email,
required String password,
});
Future<Either<Failure, void>> logout();
}
// use case — single responsibility
class LoginUseCase {
final AuthRepository _repo;
const LoginUseCase(this._repo);
Future<Either<Failure, UserEntity>> call(LoginParams params) =>
_repo.login(email: params.email, password: params.password);
}
**
Data Layer — Repository Implementation
**
CODE
class AuthRepositoryImpl implements AuthRepository {
final AuthRemoteDataSource _remote;
AuthRepositoryImpl(this._remote);
@override
Future<Either<Failure, UserEntity>> login({
required String email,
required String password,
}) async {
try {
final model = await _remote.login(email: email, password: password);
return Right(model);
} on ServerException catch (e) {
return Left(ServerFailure(e.message));
} on NetworkException {
return Left(const NetworkFailure('No internet connection'));
}
}
}
**
Presentation Layer — Bloc
**
CODE
class AuthBloc extends Bloc<AuthEvent, AuthState> {
final LoginUseCase _loginUseCase;
AuthBloc({required LoginUseCase loginUseCase})
: _loginUseCase = loginUseCase,
super(AuthInitial()) {
on<LoginRequested>(_onLoginRequested);
}
Future<void> _onLoginRequested(
LoginRequested event,
Emitter<AuthState> emit,
) async {
emit(AuthLoading());
final result = await _loginUseCase(
LoginParams(email: event.email, password: event.password),
);
result.fold(
(failure) => emit(AuthError(failure.message)),
(user) => emit(AuthAuthenticated(user)),
);
}
}
**
Dependency Injection with GetIt
**
CODE
final sl = GetIt.instance;
Future<void> init() async {
sl.registerFactory(() => AuthBloc(loginUseCase: sl()));
sl.registerLazySingleton(() => LoginUseCase(sl()));
sl.registerLazySingleton<AuthRepository>(
() => AuthRepositoryImpl(sl()),
);
sl.registerLazySingleton<AuthRemoteDataSource>(
() => AuthRemoteDataSourceImpl(firebaseAuth: sl()),
);
sl.registerLazySingleton(() => FirebaseAuth.instance);
}
**
Key Rules
**
Entities have no packages (pure Dart classes only). Models extend entities and add fromJson/toJson. Use cases have one call() method. Blocs live in the presentation layer only. Always use Either to handle errors explicitly.
Vollständiger Original-Artikel
Den kompletten Beitrag mit allen Details direkt auf dev.to lesen.
SOCIAL SHARE CARD GENERATOR