Critical Patterns

Widget Structure (REQUIRED)

// ✅ ALWAYS: Prefer StatelessWidget when possible class UserCard extends StatelessWidget { final User user;

const UserCard({super.key, required this.user});

@override Widget build(BuildContext context) { return Card( child: ListTile( title: Text(user.name), subtitle: Text(user.email), ), ); } }

State Management (REQUIRED)

// ✅ Use Riverpod for state management final userProvider = FutureProvider<User>((ref) async { return await api.getUser(); });

// In widget Consumer( builder: (context, ref, child) { final userAsync = ref.watch(userProvider); return userAsync.when( data: (user) => Text(user.name), loading: () => CircularProgressIndicator(), error: (e, s) => Text('Error: $e'), ); }, )

Null Safety (REQUIRED)

// ✅ ALWAYS: Use null safety properly String? nullableName; String nonNullName = nullableName ?? 'Default';

// Use late for lazy initialization late final UserService userService;

Decision Tree

Need simple UI? → StatelessWidget Need local state? → StatefulWidget Need shared state? → Provider/Riverpod Need navigation? → GoRouter Need forms? → Form + TextFormField

Commands

flutter create myapp flutter run flutter build apk flutter build ios flutter test flutter analyze