State Management in Flutter 3.19: Everything You Need to Know

In the dynamic world of mobile app development, efficiency and scalability are paramount, especially when dealing with large-scale applications. Flutter manages the complexity of mobile app development by providing cross-platform functionality. Flutter, a popular framework for mobile app development, has consistently pushed the boundaries of innovation. The latest version of Flutter 3.19, brings new features that aim to make the development experience easier and more user-friendly. One of the best features that Flutter provides is State Management.

State management simplifies the whole navigation process from one screen to another and makes a smooth and seamless user experience. For both experienced and new Flutter developers, this blog offers practical guidance on choosing the best state management strategy for your next project.

State Management in Flutter

In Flutter, state management plays a crucial role that ensures a response and maintains user experience. It is an essential element that acts as the central nervous system which keeps track of all the dynamic data that influences the app's behavior. This data can encompass use interactions, server responses, and internal data modifications. Effective state management guarantees that the UI reflects these changes accurately which allows the app to respond appropriately.

Examples of state in the Flutter app include user preferences, authentication status, real-time data retrieved from APIs, and navigation flow between mobile screens. By well maintaining this state in Flutter, developers can ensure the UI reflects these changes accurately and the app responds appropriately to user actions.

Flutter offers a versatile toolbox for state management that ranges from the fundamental setState function for simpler applications to more elaborate patterns like the BLoC, GetX, etc. The optimal approach is based on the specific requirements of the application being developed.

Why State Management Is Important In Flutter 3.19

State management in Flutter acts as an app memory that stores crucial information like login status, user preferences, and more. It allows you to centrally manage this data and ensure it flows seamlessly throughout your app. This is what empowers your app to adapt to user interactions and deliver a consistently delightful user experience. Let’s check the reasons why State management is important for Flutter.

• Personalized Experiences

  State management helps to create dynamic UIs that adapt to user actions and data that make your app feel more responsive and engaging.

• Consistent Behavior

  Consider an app that resets your counter to zero every time you navigate away and back. With state management, you can keep your app's behavior consistent and predictable across screens.

• Scalability and Maintainability

  State management libraries provide structured ways to handle data that make your codebase more organized and easier to maintain, especially for complex apps.

Additionally, opting for Flutter for mobile app development can lead to enhanced application quality, speed, and design. However, selecting the appropriate state management approach can be challenging. Hence, it's essential to explore various state management patterns, their implementation methods, and their respective pros and cons to make an informed decision based on specific project requirements.

5+ Flutter State Management Packages

Flutter offers various state management packages to handle the state of your widgets. Here's a breakdown of some popular packages:

1. Riverpod

A relatively new library inspired by Provider, Riverpod offers a simplified approach with a single source of truth for state management. It utilizes Providers to manage state and avoids boilerplate code with features like automatic provider scoping and change detection.

Advantages of Riverpod State Management Library

• Easy to learn and use, with a clean and concise API.
• Improves code organization and reduces boilerplate compared to Provider.
• Automatic change detection ensures efficient UI updates.
• Well-suited for both small and large applications.



Disadvantages of Riverpod State Management Library

• Under development state with a smaller community compared to Provider.
• Lack of some features available in other solutions.



How Riverpod Library Works

Let’s discuss the working process of Riverpod with an example:

Step 1: Define network requests by writing a function annotated with @riverpod

@riverpod
Future<String> movieSuggestion(MovieSuggestionRef ref) async {
final response = await http.get(
     Uri.https('https://xyz.com/api/movie'),
);
final json = jsonDecode(response.body);
     return json['activity']! as String;
}

Step 2. Listen to the network request in your UI and gracefully handle loading/error states.

class Home extends ConsumerWidget {
@override
Widget build(BuildContext context, WidgetRef ref) {
final movieSuggestion = ref.watch(MovieSuggestionProvider);
      return movieSuggestion.when(
      loading: () => Text('loading'),
      error: (error, stackTrace) => Text('error: $error'),
      data: (data) => Text(data),
      );
   }
}

2. GetX

GetX is a popular solution that combines dependency injection and state management features. It offers a simpler approach with features like state management, dependency injection, and navigation.

Explore More: Reasons Why GetX is Not Recommended For Large-Scale Apps

Advantages of GetX State Management Library

• Easy to learn and use, with a concise and intuitive API.
• Offers features beyond just state management, making it a versatile solution.
• Well-suited for smaller to medium-sized applications due to its simplicity.



Disadvantages of GetX State Management Library

• GetX enforces a specific structure, which might not be suitable for all project needs or preferences.
• The tight integration between state management, navigation, and dependencies might lead to less flexibility in complex scenarios.
• Testing GetX apps can be more complex due to the intertwined nature of state and navigation.



How GetX Library Works

Let's create a simple counter app using GetX to demonstrate these concepts:

Step 1: Create the Main Function and Launch the App

void main() => runApp(GetMaterialApp(home: Home()));

Step 2: Define a State Management Class (Controller)

class Controller extends GetxController{
          var count = 0.obs;
          increment() => count++;
}

Step 3: Build the UI (Home and Other classes)

class Home extends StatelessWidget {
@override
Widget build(context) {
          
  final Controller c = Get.put(Controller());

  return Scaffold(
   appBar: AppBar(title: Obx(() => Text("Clicks: ${c.count}"))),
   body: Center(child: ElevatedButton(
       child: Text("Go to Other"), onPressed: () => Get.to(Other()))),
   floatingActionButton:
        FloatingActionButton(child: Icon(Icons.add), onPressed: c.increment));
    }
}

class Other extends StatelessWidget {
final Controller c = Get.find();

@override
Widget build(context){
 return Scaffold(body: Center(child: Text("${c.count}")));
  }
}

3. BLoC (Business Logic Component) Pattern

BLoC is a well-established pattern that separates business logic (events and states) from the UI. It promotes unidirectional data flow and improves testability. BLoC requires implementing Bloc classes for state management.

Explore More: Why Bloc Used in Large-Scale Apps

Advantages of BLoC State Management Library

• Offers a high degree of control and separation of concerns.
• Promotes predictable state updates with unidirectional data flow.
• Well-suited for complex applications.



Disadvantages of BLoC State Management Library

• Implementing BLoC from Scratch can involve writing more boilerplate code compared to some other solutions.
• Understanding and implementing BLoC effectively might require a steeper learning curve for newcomers.
• Managing multiple BLoC classes for various parts of the app can become complex.



How BLoC Library Works

Let's create a simple counter app using BLoC to demonstrate these concepts:

Step 1. Create counter_event.dart file

abstract class CounterEvent extends Equitable{}

class IncrementCounter extends CounterEvent {
  const IncrementCounter();

  @override
  List<Object> get props => [];
 }

class DecrementCounter extends CounterEvent {
  const DecrementCounter();

  @override
  List<Object> get props => [];
}

Step 2. Create counter_state.dart file

abstract class CounterState extends Equitable{}
class NewValueLoading extends CounterState {
 const NewValueLoading();
 @override
 List<Object> get props => [value];
}
class NewCounterValue extends CounterState {
 const NewCounterValue(this.value);
 final int value;
 @override
 List<Object> get props => [value];
}

Step 3: Implement Counter BLoC

class CounterBloc extends Bloc<CounterEvent, CounterState> {
int counter = 0;
CounterBloc() : super(NewCounterValue(counter)) {
   on<IncrementCounter>((event, emit) {
      emit(NewValueLoading());
      emit(NewCounterValue(++counter));
   });
   on<DecrementCounter>((event, emit) {
      emit(NewValueLoading());
      emit(NewCounterValue(--counter));
   });
 }
}

Step 4: Create the Main App Widget

class App extends StatelessWidget {
  const App({super.key});
  @override
  Widget build(BuildContext context) {
    return BlocProvider(
    create: (_) => CounterBloc(),
    child: const CounterView(),
  );
 }
}

Step 5: Build the Counter View

class CounterView extends StatelessWidget {
  const CounterView({super.key});

   @override
    Widget build(BuildContext context) {
        return Scaffold(
         appBar: AppBar(title: const Text('Counter')),
          body: Center(
        	  child: BlocBuilder<CounterBloc, CounterState>(
                  builder: (context, state) {
                    if(state is NewCounterValue){
                      return Text(
                         '${state.value}',
                        style: Theme.of(context).textTheme.displayLarge,
                      );                      
                    }
                    return Text(
                      'Loading',
                      style: Theme.of(context).textTheme.displayLarge,
                    );
                },
           ),
       ),
       floatingActionButton: Column(
         crossAxisAlignment: CrossAxisAlignment.end,
         mainAxisAlignment: MainAxisAlignment.end,
         children: <Widget>[
           FloatingActionButton(
              child: const Icon(Icons.add),
              onPressed: () {
                context.read<CounterBloc>().add(IncrementCounter());
              },
           ),
           const SizedBox(height: 4),
           FloatingActionButton(
             child: const Icon(Icons.remove),
             onPressed: () {
               context.read<CounterBloc>().add(DecrementCounter());
             },
           ),
         ],
       ),
     );
   }
}

4. Provider

A widely used and versatile solution, Provider is a dependency injection library with built-in state management capabilities. It utilizes Providers to manage the state and allows for dependency injection across the widget tree.

Advantages of Provider State Management Library

• Well-documented and mature library with a large community and resources.
• Flexible and can used for various state management requirements.
• Integrates well with other libraries like Riverpod for a more modular approach.



Disadvantages of Provider State Management Library

• When managing complex states, Provider might require more boilerplate code compared to Riverpod.
• Manual handling of state updates can be cumbersome.

How Provider State Management Library Works in Flutter 3.19

Let’s discuss Provider library with simple example:

Step 1: Configure State Management with ChangeNotifierProvider

void main() {
  runApp(
    MultiProvider(
      providers: [
       ChangeNotifierProvider(create: (_) => Counter()),
      ],
    child: const MyApp(),
   ),
 );
}

Step 2: Implement the Counter with ChangeNotifier

class Counter with ChangeNotifier{
  int _count = 0;
  int get count => _count;
  void increment() {
    _count++;
    notifyListeners();
  }
}

Step 3: Build the Main Application Widget

class MyApp extends StatelessWidget {
   const MyApp({Key? key}) : super(key: key);
   @override
   Widget build(BuildContext context) {
     return const MaterialApp(
       home: MyHomePage(),
    );
  }
}

Step 4: Construct the Home Screen UI

class MyHomePage extends StatelessWidget {
   const MyHomePage({Key? key}) : super(key: key);
   @override
   Widget build(BuildContext context) {
     return Scaffold(
       appBar: AppBar(
         title: const Text('Example'),
       ),
       body: const Center(
        child: Column(
          mainAxisSize: MainAxisSize.min,
          mainAxisAlignment: MainAxisAlignment.center,
          children: <Widget>[
            Text('You have pushed the button this many times:'),
            Text(
             '${context.watch<Counter>().count}',
              key: const Key('counterState'),
              style: Theme.of(context).textTheme.headlineMedium,
            ),
          ],
       ),
     ),
     floatingActionButton: FloatingActionButton(
        key: const Key('increment_floatingActionButton'),
        onPressed: () => context.read<Counter>().increment(),
        tooltip: 'Increment',
        child: const Icon(Icons.add),
     ),
   );
 }
}

5. MobX

MobX is a state management library based on reactive programming. It uses observables to automatically update UI components whenever the underlying state changes. MobX offers a simpler and more intuitive way to manage the application state.

Advantages of MobX State Management Library

• Easy to learn and use, with a concise and intuitive API.
• Simplifies state management with automatic UI updates based on observables.
• Well-suited for complex applications with frequently changing states.



Disadvantages of MobX State Management Library

• Can introduce additional overhead compared to simpler solutions.
• Might require a shift in mindset for developers not familiar with reactive programming.



How MobX Library Works

Let's create a simple counter app using MobX to demonstrate these concepts:

Step 1: Define the Base Counter Class with MobX Annotations

class Counter = _Counter with _$Counter;
 abstract class _Counter with Store {
  @observable
  int value = 0;
  @action
  void increment() {
    value++;
  }
}

Step 2: Generate MobX Observables and Actions using Mixin

mixin _$Counter on _Counter, Store {
  late final _$valueAtom = Atom(name: '_Counter.value', context: context);
  @override
  int get value {
    _$valueAtom.reportRead();
    return super.value;
  }
  @override
  set value(int value) {
    _$valueAtom.reportWrite(value, super.value, () {
      super.value = value;
    }); 
  }
  late final _$_CounterActionController =
    ActionController(name: '_Counter', context: context);
  @override
  void increment() {
    final _$actionInfo =
      _$_CounterActionController.startAction(name: '_Counter.increment');
    try {
      return super.increment();
    } finally {
       _$_CounterActionController.endAction(_$actionInfo);
    }
  }
  @override
  String toString() {
    return '''
    value: ${value}
    ''';
  }
}

Step 3. Create the Counter Example State and UI with MobX Integration

class CounterExampleState extends State<CounterExample> {
  final Counter counter = Counter();
  @override
  Widget build(BuildContext context) => Scaffold(
    appBar: AppBar(
       backgroundColor: Colors.blue,
       title: const Text('MobX Counter'),
    ),
    body: Center(
      child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: <Widget>[
             const Text(
                 'You have pushed the button this many times:',
             ),
             Observer(
                builder: (_) => Text(
                  '${counter.value}',
                   style: const TextStyle(fontSize: 40),
                 )
             ),
           ],
         ),
       ),
       floatingActionButton: FloatingActionButton(
          onPressed: counter.increment,
          tooltip: 'Increment',
          child: const Icon(Icons.add),
       ),
   );
}

6. Redux

Redux is a predictable state container pattern. It enforces a unidirectional data flow for state updates, making it highly testable and scalable. While not originally designed for Flutter, Redux can be integrated with Flutter using third-party libraries.

Advantages of Redux State Management Library

• Proven track record and strong developer tooling support from the React ecosystem.
• Unidirectional data flow ensures predictable and testable state management.
• Well-suited for large and complex applications with extensive state management needs.



How Redux Library Works

Explore the working process of the Redux library using the following example:

Step 1: Define an Enum for Actions in Redux

num Actions { Increment }

Step 2: Create a Counter Reducer Function

int counterReducer(int state, dynamic action) {
  if (action == Actions.Increment) {
    return state + 1;
  }
  return state;
}

Step 3: Setup the Redux Store in the Main Function

void main() {
   final store = Store<int>(counterReducer, initialState: 0);
   runApp(FlutterReduxApp(
     title: 'Flutter Redux Demo',
     store: store,
   )
 );
}

Step 4: Build the Flutter Redux App with StoreProvider

class FlutterReduxApp extends StatelessWidget {
   final Store<int> store;
   final String title;

   FlutterReduxApp({
     Key? key,
     required this.store,
     required this.title,
   }) : super(key: key);

   @override
   Widget build(BuildContext context) {
     return StoreProvider<int>(
       store: store,
       child: MaterialApp(
         theme: ThemeData.dark(),
         title: title,
         home: Scaffold(
           appBar: AppBar(
             title: Text(title),
           ),
         body: Center(
           child: Column(
             mainAxisAlignment: MainAxisAlignment.center,
             children: [
               StoreConnector<int, String>(
                  converter: (store) => store.state.toString(),
                  builder: (context, count) {
                     return Text(
                      'The button has been pushed this many times: $count',
                       style: Theme.of(context).textTheme.headline4,
                     );
                   },
                 )
               ],
             ),
            ),
            floatingActionButton: StoreConnector<int, VoidCallback>(
              converter: (store) {
                return () => store.dispatch(Actions.Increment);
            },
            builder: (context, callback) {
              return FloatingActionButton(
                 onPressed: callback,
                 tooltip: 'Increment',
                 child: Icon(Icons.add),
              );
           },
         ),
       ),
     ),
   );
 }
}

You have to choose a specific relevant State Management Library that is best suitable for your requirements.

Key Differences of Flutter 3.19 State Management Libraries

Here's a breakdown of the key differences between popular Flutter state management libraries including Riverpod, BLoC, GetX, Redux, MobX, and Provider.

Ultimately, the best way to choose state management libraries in Flutter is to try some libraries and see which fits your project and team workflow best. Let’s move towards the challenges faced during the implementation or using state management in Flutter 3.19 for Large Apps.

Wrapping Up

State management in Flutter 3.19 plays a pivotal role in building large-scale apps that deliver a smooth and consistent user experience. Understand the core concepts, explore different libraries, and adopt the best practices outlined in this blog, you’ll be well-equipped to tackle the challenges of complex app development.

Remember, the ideal state management approach depends on your project requirements. Consider different factors, experiment, and learn continuously to refine your strategy to build robust and scalable Flutter applications that thrive under the demands of growth.

If you want to outsource your Flutter project, we at, CodeTrade have a team of highly experienced Flutter developers who can work closely with your project and make your project outstanding that stand in the crowd. Contact CodeTrade today to hire Flutter Developers for your project.