Essential Guide on Flutter State Management – Best Practices

Picture this: You stepped into a bustling restaurant, with servers running to the kitchen, chefs searching the inventory for the following order, and clients waiting for their orders to be served. A chaotic “STATE”.

The state management of the restaurant needs to be better.

On the contrary – Think of a well-managed restaurant with all the orders served on time, servers receiving and delivering orders, and chefs managing the orders on time. A restaurant running in a good state owes to a good manager/owner.  

Think of a Flutter app with a well-managed UI, accuracy, speed, and performance to give a great Flutter app. The app is running smoothly. Here, the real hero at play is state management. When not working with the proper flow, the Flutter app might behave as a chaotic restaurant, leaving no place for new functions to run correctly.  

As the restaurant owner is the heart of the place and manages everything, state management in Flutter is the heart.

Now, what is state or state management in Flutter?

What is a State?

A state is not always readable when the widget is created. It refers to the mutable data associated with a StatefulWidget, which can change during the lifecycle of the widget. The setState() function, provided for Stateful widgets, can be used to update the state object if you wish to modify your widget. We can modify the properties of the state object that causes a UI to redraw by using the setState() function.

What is State Management?

The main goal of state management in Flutter and Dart is to control the data that the application renders and how it reacts to user input. It involves monitoring state changes and adjusting the user interface to take these changes into account. It regulates how data flows and changes over time, acting as your application’s brain.

Let’s understand with an example-

As a restaurant owner or manager, things like food orders, menus, inventory needs, and whatnot pass through the manager. The manager or owner is the person who maintains the proper functioning of the restaurant.

State Management in Flutter can be divided into two categories. Here, we explain this with the help of a restaurant example. 

• Ephemeral State
• App State

Ephemeral State 

Picture yourself at a restaurant when the waiter brings your order. The food is on the table in front of you. Now, when you take an action (eating, drinking) on your meal, the current state of the table will change. But nobody is affected by your actions. Nobody else cares what you do with your food. Thus, this is a local state that solely impacts you. Similarly, in private exchange in Flutter, setState is restricted to a single StatefulWidget (i.e., your meal). This state is sometimes called the UI state.

App State 

Consider yourself the manager of the restaurant, in charge of making sure that all of the staff assignments, cooking, and orders go without a hitch. All employees of the restaurant rely on this information, such as the kitchen knowing what to cook or the servers knowing where to serve. If there is any change in the manager, then all those who are connected with the manager will be affected: staff, chefs, and eventually clients.

Similarly, when you call the “State,” or if there is a change in the “state,” then other connected widgets will be affected by it. That’s why it is referred to as “Global State.”

Why is Flutter State Management Needed?

State management is essential to Flutter’s reactive UI framework since the application needs to know when to rebuild certain interface elements. The application may act erratically without adequate state management, which could result in needless rebuilds, performance snags, or difficult-to-trace problems. Effective state management guarantees that:

• When the state changes, the UI responds appropriately.
• Performance stays at its peak.
• The architecture of the software is maintainable and scalable.

To achieve optimized performance in Flutter app development, state management in Flutter is of utmost importance. 

Stateful vs Stateless

The two concepts are best depicted in the image. 

Just a heads up – 

Mutable data – Data or information that is changeable in the code lifecycle.

Immutable Data – Fix or constant data, i.e., data once defined in the code will remain the same during the entire code lifecycle. 

Read more about the Flutter basics and Flutter for hybrid apps in this article.

setState 

Flutter’s built-in state management mechanism is called Stateful Widgets. They are made up of two classes:

`State` and `StatefulWidget`.

The mutable state data is contained in the `State` object, whereas the immutable part of the widget is represented by the `StatefulWidget.`

Calling `setState()` causes the widget to be rebuilt and the user interface to be updated whenever the state data changes.

You can tell Flutter that the widget’s state has changed by using the setState method, which will cause the user interface to be rebuilt.

Where the states are absent, they are called stateless widgets. It means neither the widget nor the user interface will be changed if the data changes. 

Flutter State Management Approaches

Flutter has a number of pre-installed tools and methods for handling state. You have the freedom to select the best strategy for your app’s requirements thanks to these tools, which range from basic and easy to more complex possibilities. 

We have ranked the various methods according to their level of popularity, placing the most widely used at the top. (Don’t believe us, then refer to pub.dev or Github) 

1. BLoC

   In Flutter, the BLoC (Business Logic Component) design is frequently utilized for state management, particularly in intricate applications.

   Streams are used to manage and disseminate state changes, and the user interface and business logic are kept apart.

   The Bloc pattern is commonly implemented using the `flutter_bloc` package.

2. GetX

   For Flutter, GetX is a robust and small state management library. It offers a high-performance and streamlined method for handling navigation, injecting dependencies, and managing state.

   GetX is known for its effectiveness and ease of use. It is well-liked by the community because of its quick learning curve. The only shortcoming is that it has been a year since it was updated. 

3. Provider

   The provider remains one of the most popular state management libraries for Flutter because the Flutter team has officially recommended it. It lets you make and control the providers that store the state of the application. Widgets can then listen to these providers for state changes.

   How to Get Notifier Value in Flutter?

   Flutter has two classes, ValueNotifier and ChangeNotifier, to help you manage the mutable state of your application. Although their implementation and use cases vary slightly, they are both helpful in alerting listeners when the state changes.

   A Flutter generic class called ValueNotifier contains a single value of type T. It is a lightweight and easy method for handling mutable states in your program.

   A ValueNotifier alerts its listeners when its value changes, which causes any widgets that rely on that value to rebuild.

   ValueNotifier is helpful for handling straightforward states that don’t call for intricate data conversions or reasoning.

   ValueNotifier is better suited for simple state changes within a widget and is not ideal for shared/global states.

   The provider is beneficial for shared or global state management.

4. Riverpod

   A state management package called Riverpod was created to simplify state administration while addressing some of the drawbacks of “Provider.” Unlike Provider, Riverpod introduces a more declarative API, ensuring better compile-time safety and eliminating reliance on the widget tree for dependency injection.

   Because of its scalability and flexibility, it’s a great option for sophisticated large-scale systems that need reliable and efficient state management. Riverpod simplifies state management with an alternative approach, offering developers greater control and scalability.

5. MobX

   Observables and reactions are the main focus of this reactive state management library. It draws the inspiration from a Javascript library named Mob X.

   It is helpful for creating applications with complex and dynamic user interfaces.

   MobX boilerplate has been reduced significantly with the introduction of mobx_codegen.

6. Redux

   Redux from JavaScript served as the model for this predictable state container. It uses actions to update the entire program state, which is stored in a single, unchangeable store.

   Redux is generally considered verbose and is not widely adopted in modern Flutter apps due to its complexity. It is still suitable for apps needing predictable, centralized state management but may not be the best choice for most projects.

Challenges in Flutter State Management

Although Flutter is a compelling and flexible framework, however, some challenges persist. Some challenges are – 

1. Over-Complex State Management

   Overusing state can lead to bloated code and make it difficult to reason about the application’s behavior. Deeply nested state structures can become hard to manage and maintain.

2. Performance Issues

   Unnecessary rebuilds can impact app performance, especially for complex UIs. Inefficient state updates can slow down the app, mainly when dealing with large datasets.

3. Managing Asynchronous Operations

   Handling asynchronous operations, such as fetching data from APIs, can be complex when managing state in Flutter. Proper error handling and state management are essential for ensuring a smooth user experience.

   In Flutter, native tools like FutureBuilder and StreamBuilder provide straightforward ways to manage asynchronous operations. These widgets are particularly useful for beginners or smaller-scale applications, offering a simple approach to handle futures and streams directly in the widget tree. They often serve as a stepping stone before introducing more advanced state management solutions like Riverpod or Bloc.

4. Sharing State Across Widgets

   Using a global state can make code harder to reason about and maintain. Determining the appropriate context for sharing state can be challenging.

5. State Persistence

   Persisting state across app sessions can be necessary for specific use cases but requires careful consideration. Ensuring data consistency between local state and external sources can be complex while synchronizing the data. 

6. Testing and Debugging

   Creating mock classes and testing state-related logic can be challenging, especially for complex applications. Identifying and fixing state-related bugs can be time-consuming.

Best Practices in State Management

When creating a responsive and practical Flutter application, state management is essential. To keep your app in excellent condition, follow these important recommended practices:

• Make Sensible Decisions: Choose the state management strategy that best suits the complexity of your project. Built-in widgets may be adequate for simple applications, but Bloc or Redux may be more advantageous for complex ones. Another point to consider when choosing an approach is to pick the most updated package. Regular updates keep the packages running smoothly and have fewer issues than outdated ones.   
• Separation of Concerns: Keep your business logic (data management) and user interface (presentation) distinct. This encourages easier maintenance and cleaner code.
• Reduce State: Only handle information that is actually dynamic and necessary for your user interface. Steer clear of pointless state updates that could affect performance.
• Use Stateless Widgets: For UI elements that don’t need state management, whenever feasible, use stateless widgets. This increases efficiency and streamlines your code. 
• Immutable Data: Try to employ immutable data structures (such as those that cannot be altered) whenever possible. This makes it easier to reason about the state of your app and improves predictability.
• Efficient State Management: Testing procedures for state management should be an integral part of your development process to ensure the proper operation of your state management logic. It’s essential to recognize that stateless widgets can still rely on external states, such as InheritedWidget, Provider, or other reactive libraries. While they lack an internal state, this does not mean they are entirely independent of state management.
• Const in Flutter: The constant constructor, or const, in Flutter, is used to optimize performance and improve the readability and maintainability of code. It plays a key role in making widget tree management more efficient.

However, it’s important to note that using const constructors only provides optimization benefits when the widget’s data remains unchanged. For dynamic or frequently changing data, const does not offer performance gains. Emphasizing this distinction ensures developers use const appropriately to maximize efficiency.

Following the latest Flutter trends is also one of the best practices for developing modern and relevant apps.  

Factors in Choosing the Right State Management Technique in Flutter

The following criteria determine whether state management strategy is best:

• Complexity Level

  SetState will work on easy applications. However, you need a more robust approach, like Bloc or Riverpod, for projects that are medium to more complicated. The approach depends on the complexity of your application. 

• Scalability

  Consider how your strategy will expand as your app does. Riverpod and the provider are very scalable.

• Usability

  GetX’s simplicity makes it a good choice if you’re looking for something quick and simple to adopt.

• Support From the Community

  Having a strategy with solid documentation and the backing of the community is beneficial. Because it is a component of the Flutter ecosystem, Provider has a sizable community and extensive documentation.

From the Lens of a Flutter Developer

This section contains the pearls of wisdom of Flutter developers we interviewed –

In Flutter, while working on state management, it is never a “one-size-fits-all” decision. What works well for one developer or project may not necessarily suit another. The beauty of Flutter lies in its flexibility, allowing developers to choose the state management solution that aligns with their project needs and coding choices.

“State management is about independent choices.” The decision to use Provider, Bloc, GetX, or Riverpod ultimately depends on the project’s complexity, the development team’s experience, and the scalability requirements. While some developers favor GetX for its simplicity and ease of use, others might prefer Riverpod for its improved dependency injection model. 

However, the current fave, BLoC (Business Logic Component), remains one of the most popular choices, especially for large-scale and complex projects. Its structured approach with clear separation of business logic and UI makes it scalable, maintainable, and flexible—ideal for applications that need to grow over time.

Avoiding “Cocktails” of Multiple State Management Approaches

A common mistake is combining multiple state management techniques without a clear strategy—what some developers call a “cocktail.” This can make the codebase messy and challenging to maintain, resulting in conflicting logic and unexpected behavior. The recommendation is to stick to one approach or a well-planned combination if absolutely necessary, such as using setState for the local state and Bloc for the app-wide state.

FAQs:

1. Which state management is best in Flutter?

There is no best in flutter state management. Every approach has its pros and cons. According to the usability and the features they provide, coders/developers can choose their pick.

2. Can We Use Two Different State Management in Flutter?

You can use two different state management approaches. However, it is not advisable. A simple reason is this makes the code messy and complicated to maintain.

3. When should you use state management in Flutter?

Using Flutter state management depends on many factors like app complexity, app size, and requirements. Sometimes, to notify other parts of the app, the shared state is updated.

4. Is RiverPod better than BLoC?

This is a never-ending debate. Some developers prefer BLoC, while others prefer RiverPod. Both approaches are popular. It is on the developer to choose according to his code preferences and coding experience.