Flutter State Management

8 mins

Ashutosh Rawat

Published on Aug 8, 2024

Flutter State Management Explained: How to Choose the Right Approach

Introduction

In Flutter development, State management in Flutter is about managing the state of your app. In this, “state” means the data that affects the UI at any given time. How you manage this state determines the user experience – whether it’s a simple counter app or a complex social media app. For example, think of a shopping cart: how items are added, updated, or deleted is state management. Without proper state management, an application will start acting unpredictably, frustrating users and making it difficult for developers to maintain.

What you will learn in this article

By the end of this post, you will have a clear understanding of most of the state management approaches available in Flutter, from simple methods like setState() to more advanced solutions like Bloc and Riverpod. You will learn how these approaches work and when to use them. It’s not one-size-fits-all, choosing the right approach depends on the size of your project, your team’s experience, and long-term goals. It will guide you in deciding how to ensure that your Flutter app is not only functional but also easy to maintain and develop.

Understanding State Management in Flutter

What is state management?

Flutter state management simply means handling the data your app uses to display and interact with. In simple terms, “state” refers to the current state or data of your app at any given time—such as whether a user is logged in or not, what items are in their shopping cart, or what page they are currently viewing. State management is the way you control, update, and track these data changes to ensure your app works well. Without state management, the app will not be able to recover those states, so it will neither be able to present the correct information nor react correctly to the user’s actions, leading to a confusing or unusable experience.

Why State Management Matters

So, state management is important—it maintains the flow and logic of your app. Imagine a news application whose view is populated by an internet resource through some articles. Now, if the user would like to refresh their feed, the application has to fetch the data and update the display. If the state change is not handled properly, it can end up in a view that shows old data or crashes when trying to update with new data. This means that state management provides the user with the right data at the right time and the application responds accordingly to user interactions, whether it is a button press, form filling, or navigation between screens.

In short, good state management keeps your application predictable and reliable. This is what makes the application feel smooth and responsive – whether the user is casually browsing or engaged in some important task. Without it, the most brilliantly designed app becomes frustrating to use, where the flow and logic break down under the weight of poor data handling.

Ephemeral State vs. App State in Flutter

In Flutter, state management is classified into two conceptual types, which are given below:

Ephemeral State

Ephemeral state, also known as local or UI state, is used for managing data within a single widget. It is typically simple and short-lived, such as handling the text input of a text field or the state of a button. This type of state does not require complex management techniques; it can be handled directly within the widget using setState(). For example, if the label of a button changes when it is clicked, the _name variable in the widget can be updated using setState(), and the UI will reflect this change.

class MyHomepage extends StatefulWidget {  
  @override  
  MyHomepageState createState() => MyHomepageState();  
}  
  
class MyHomepageState extends State<MyHomepage> {  
  String _name = "Peter";  
  
  @override  
  Widget build(BuildContext context) {  
    return RaisedButton(  
        child: Text(_name),  
        onPressed: () {  
           setState(() {  
              _name = _name == "Peter" ? "John" : "Peter";  
           });  
         },  
      );  
  }  
}

App State

App state, on the other hand, is used to manage data that needs to be shared across different parts of the app and preserved between user sessions. This includes information like user preferences, login status, or the contents of a shopping cart. Unlike ephemeral state, app state requires more robust management techniques. Solutions like Provider or Riverpod help in efficiently managing and sharing this state across the entire app. For instance, the contents of a shopping cart need to be accessible from various screens, which is handled through app state management.

Examples of Application State:

User Preferences
Login Information
Notifications in a Social Networking App
Shopping Cart in an E-Commerce App
Read/Unread Status of Articles in a News App

When managing app state, it’s essential to research your options carefully. Your choice will depend on factors such as the complexity of your app, your team's prior experience, and various other considerations. Continue reading to explore these aspects in detail.

No Clear-Cut Rules

You can technically manage all your app's state with State and setState(). The Flutter team does this in many simple examples, like the starter app you get with flutter create.

Well, sometimes things are not that obvious. For example, the selected tab of a bottom navigation bar might not be just a temporary state. You most likely would need to change it from the outside of a class, or keep it consistent between sessions. In that case, that is more like app state.

There is no universal rule here. Very often, what starts as temporary state will become app state as your app grows. Be flexible and ready to adapt.

In summary, the ephemeral state is for widget-specific data, while the app state is for global data shared throughout the app.

Overview of Popular Flutter State Management Approaches

Overview of setState() in Flutter, its best use cases for simple UI updates, and a summary of its pros and cons

1. setState()

How It Works: The setState() method is the most basic way to manage the state in Flutter. When you call setState(), Flutter knows that something has changed and needs to update the UI. It's perfect for small, simple state changes.

Best Use Cases: Ideal for straightforward applications where the state is local to a single widget, like updating a counter or toggling visibility.

Pros:

Simple and Easy to Use: No additional libraries are needed.
Great for Beginners: Easy to understand and implement.

Cons:

Limited Scope: Not suitable for complex apps with extensive state needs.
Less Efficient: This can lead to inefficient rebuilds if not managed carefully.

Explanation of Provider as a state management solution in Flutter, including ideal use cases for apps with moderate complexity, and a summary of its pros and cons.

2. Provider

Explanation: Provider is a popular state management solution that uses an "InheritWidget" to provide and consume state across the widget tree. It allows for more scalable state management compared to setState().

Ideal Use Cases: Perfect for apps with moderate complexity where state needs to be shared across multiple widgets or pages, such as user settings or app themes.

Pros:

Scalable: Handles more complex state management scenarios.
Flexible: Easy to integrate with existing code and libraries.

Cons:

Learning Curve: Might be complex for beginners.
Overhead: This can add extra layers of abstraction, making debugging a bit more challenging.

3. Riverpod

Description: Riverpod is an advanced state management solution that builds on Provider but addresses some of its limitations. It introduces a more robust way to manage state with better performance and safety features.

Use Cases: Ideal for large-scale applications with intricate state management requirements, such as enterprise-level apps or complex UIs.

Pros:

Improved Performance: Better handling of state and dependencies.
More Robust: Addresses some issues found in Provider, like avoiding context-related problems.

Cons:

Complexity: Can be overkill for simple apps.
Learning Curve: Requires more time to learn and implement effectively.

Overview of the Bloc pattern and architecture in Flutter, when to use it for apps with complex state management needs, and a summary of its pros and cons.

4. Bloc

Overview: The Bloc (Business Logic Component) pattern helps manage state in a predictable way by separating business logic from UI code. It uses Streams to handle state transitions and events.

When to use: Best for apps with complex state logic and where business logic needs to be separated from UI code, such as financial apps or chat applications.

Pros:

Separation of concerns: Clear separation between UI and business logic.
Predictable: State changes are controlled through events and streams, making it easier to manage complex state.

Cons:

Complex Setup: This can be difficult to set up and understand initially.
Boilerplate Code: Often requires writing a lot of boilerplate code.

Introduction to GetX as a lightweight state management solution in Flutter, its use cases for simple to moderately complex apps, and a summary of its pros and cons

5. GetX

Introduction: GetX is a lightweight and powerful state management solution known for its simplicity and performance. It combines state management, dependency injection, and route management in one package.

Use Cases: Suitable for both simple and moderately complex apps, like small business apps or personal projects where performance and simplicity are key.

Pros:

Efficient: Highly performant with minimal boilerplate code.
Integrated Features: Combines state management with dependency injection and routing.

Cons:

Less conventional: fewer adoptions compared to other solutions, and this somehow affects community support.
It is, at times, less than perfectly scalable: probably not the best solution for very large applications with highly complex state management requirements.

You will see that it will help to understand the strengths and weaknesses of each approach to state management in Flutter so that you can use the right one in your project.

Factors to Consider When Choosing a Flutter State Management Approach

Selecting the right Flutter state management strategy is vital for building a responsive and maintainable app. Here are key factors to guide your decision:

1. Project Complexity

The complexity of your app significantly impacts your choice of state management. For basic apps—like a simple counter or a single-page form—setState() may be all you need. However, as your app scales and requires managing state across multiple widgets or screens, you'll need more sophisticated solutions like Provider, Riverpod, or Bloc. These approaches are better suited for complex applications such as e-commerce platforms or social media networks where state needs to be managed globally and efficiently.

2. Team Expertise

Your team’s familiarity with Flutter and various state management solutions should also influence your choice. If the team is new to Flutter or prefers simplicity, Provider offers a straightforward and widely-used solution with plenty of community support. For teams with advanced expertise, Bloc or Riverpod might be preferable, offering more control and robustness for handling complex state scenarios but requiring a deeper understanding and experience.

3. Performance Requirements

Different state management approaches have varying impacts on app performance. For example, while setState() is lightweight and suitable for simple state updates, it can lead to unnecessary widget rebuilds in more complex scenarios. Bloc and Riverpod are designed to manage state changes efficiently , minimizing performance overhead even in large, data-intensive applications. If performance is critical—such as in real-time apps—choosing an efficient state management solution is essential.

4. Maintainability

The long-term maintainability of your codebase is crucial. Solutions like Bloc provide a clear separation between business logic and UI, making the app easier to maintain and debug over time. However, this added structure can increase complexity. On the other hand, GetX offers a more lightweight approach, which might be easier to manage initially but could become less maintainable as your app grows in complexity.

5. Community Support and Ecosystem

The strength of the Flutter community and available resources should also be a consideration. Popular solutions like Provider and Bloc benefit from extensive community support, abundant tutorials, and third-party packages that can simplify development. Emerging solutions like GetX might offer innovative features but could lack the same level of community resources, making it harder to find solutions to potential issues.

Banner promoting Blup's expert services for choosing the right state management approach in Flutter apps, with a call-to-action to check out Blup Services.

Case Studies/Examples of FSM

Let's illustrate how different state management Flutter approaches can be applied by considering three example apps with varying complexity. For each example, we are going to explain how a certain state management solution can be effectively used depending on the requirements of an application.

Example 1: Small App Using `setState()` - To-Do List App

In a simple To-Do list app, where the primary functionality is adding, deleting, and marking tasks as complete, setState() is often the go-to choice.

Why `setState()`?

Since the state of the app is local and involves direct UI updates,setState() is sufficient. You can manage the state within the same widget, such as updating the list when a new task is added or when a task is marked as complete. The simplicity of setState() aligns perfectly with the app’s limited state management needs, keeping the codebase clean and easy to maintain.

Example 2: Medium-Sized App Using Provider or GetX - E-commerce App

For medium-sized apps like e-commerce platforms, where the state is more complex and shared across multiple widgets, it is recommended to use a more robust Flutter state management solution like Provider or GetX.

Why Provider or GetX?

In an e-commerce app, you need to manage the state across different components—product lists, shopping carts, user authentication, etc. Provider allows efficient state sharing between these components, making it easier to manage global states like user sessions or shopping cart contents. Alternatively, GetX can be used for its simplicity and performance, allowing for quick and responsive UI updates without a lot of boilerplate code. Both solutions provide the scalability needed to handle medium complexity while ensuring the app remains responsive and efficient.

Example 3: Large-Scale App Using Bloc or Riverpod - Social Media App

In large-scale apps like social media platforms, where the state is highly complex and involves multiple interactions and data flows, Bloc or Riverpod becomes essential

Why Bloc or Riverpod?

Social media applications implement state management, user profile, real-time updates, and notifications. This will be the place where the Bloc approach is very useful in handling such complexity predictably and maintainably with its clear separation of business logic from UI. On the other hand, Riverpod is nothing but an extension of Provider with better performance and security features, improving complex state management requirements of the app at scale. Bloc and Riverpod are both designed to guarantee an application that can scale and stay performant for a seamless user experience.

Decision-Making Framework

Having a clear decision-making framework can be incredibly helpful when it comes to choosing the right Flutter state management approach for your project. Here’s a practical checklist to guide you through the process:

Project Complexity:
- Simple: In the case of a small application with some simple UI updates—say, for instance, a counter or to-do list app—setState() would be good enough.
- Medium: For apps where state needs to be shared across multiple widgets but isn’t too complex (e.g., an e-commerce app), consider using Provider or getX.
- Complex: If your app is large and needs to manage a complex state with a clear separation of business logic (e.g., a social media app), Bloc or Riverpod are better choices.
Team Experience:
- Beginner-friendly: If not so familiar with Flutter, the team should be in a position to digest `setState()` or `Provider easily`.
- Advanced: GetX, Bloc, or Riverpod may offer more power and flexibility for experienced developers.
Performance Requirments:
- Basic performance: For applications that have low to medium needs for performance, setState() or Provider is normally enough.
- High performance: More advanced developers may offer better power and flexibility through `GetX()`, `Bloc`, or the `Riverpod`.
Long-Term Maintainability:
- Short-Term Projects: If the app has a low-to-medium performance requirement, then `setState()` or `Provider` usually suffices.
- Scalable Projects: Maintenance and scalability in applications that might grow with time are better done with Bloc or Riverpod.
Community and Ecosystem Support:
- Established Solutions: Huge communities and thorough documentation make Provider and Bloc very reliable options.
- Cutting-Edge Tools: Though relatively new, GetX and Riverpod offer cutting-edge features and are fast-growing in popularity.

Common Pitfalls and How to Avoid Them

It's easy with Flutter state management to fall into traps that make an app harder to build and maintain. Let's look at three common pitfalls and how you can avoid them.

1. Overcomplicating Simple Projects

One of the largest mistakes developers make is slapping on some complex state management solution where it is not needed. Imagine building a simple To-Do list app—will you really need Bloc or Riverpod for that? Probably not.

How to Avoid: If this is a very small project, then it's better to stick with something as simple as setState(). It is easy to use and helps to keep your code clean. Save the more advanced tools for when your app's complexity truly demands them.

2. Disregard Performance Influence

State management will render your application smooth or sluggish, depending on how you want to use it. Suppose you have used setState() many times over in a large application; it will result in unnecessary rebuilding of UIs, slowing down the speed.

How to Avoid: Choose your state management tool based on your app's needs. In the case of medium complexity, Provider or GetX can be used to handle state without pulling down performance. For larger apps, Bloc or Riverpod gives finer control over what your app updates, so it only updates what's necessary, keeping things nice and smooth.

3. Lack of Consistency

State management inconsistencies resemble a puzzle with missing pieces—they are confusing and frustrating. At worst, this could be bug-prone, leading to maintenance hell with the use of different state management techniques in your app.

How to Avoid: Settle on one state management solution and just use it. If you use Provider, use Provider elsewhere in your app. This creates a more predictable codebase that makes your life easier when your project grows.

FAQ Section for Flutter State Management

Frequently Asked Questions About Flutter State Management

State management can be challenging in Flutter. This FAQ addresses common questions, offering insights and solutions to help you navigate and choose the best approach for your app’s needs.

Can I Mix Different State Management Solutions in Flutter?
Yes, you can mix solutions like setState() for local changes and Provider or Bloc for global state. Ensure that they work harmoniously with each other.
Which is the Best State Management Approach for Beginners in Flutter?
You should start with setState() or Provider. setState() is pretty straightforward, and Provider slowly introduces advanced concepts.
How Does State Management Affect App Performance?
High performance is obtained through proper state management. Poor management will slow down your app, so go for the right approach that gives seamless performance.
What Are the Best Practices for State Management in Large Flutter Applications?
Use scalable solutions like BLoC or Redux, and organize state management according to app sections to help keep your code base manageable.
Which State Management Approach Works Best for Complex Flutter Projects?
It will be suitable for a complex project since BLoC or Redux has advanced capabilities and support for scalability.
How Do I Choose the Right State Management Solution for My Flutter App?
You will use your decision based on the complexity of the app: Provider or Riverpod for simple apps and BLoC or Redux for complex ones.
Can State Management Solutions Impact the Testing of My Flutter App?
Yes, state management has a bearing on testing. BLoC supports test cases to business logic and state changes, but other solutions may require additional setup.
What Are Common Mistakes While Implementing State Management in Flutter?
Keep your setup simple so you know how the state lifecycle works not have any maintenance issues or performance problems.
How Can I Handle Asynchronous Operations in Flutter's State Management?
Some of the popular solutions like Riverpod and BLoC handle async tasks elegantly; use them if you want to keep your app responsive.
Does every Flutter project need some state-management solution?
The answer is no. Small apps would definitely be quite all right out of the box, simply by features of Flutter itself, but complex apps totally benefit from an oriented state management solution.

Conclusion

In summary, choosing the right state management solution in Flutter is crucial for maintaining your app’s performance and scalability. We’ve explored several options:

setState() is great for simple, local state changes.
Provider and Riverpod are suitable for moderate to complex apps, with Riverpod offering enhanced features.
Bloc and Redux excel in managing state for large, complex applications.
GetX is a lightweight, efficient choice for a range of app complexities.

Evaluate your project’s complexity, features, and team expertise to select the best state management approach. Each solution has its strengths, so align your choice with your app’s needs for optimal results.

Flutter State Management Explained: How to Choose the Right Approach

Introduction

Understanding State Management in Flutter

What is state management?

Why State Management Matters

Ephemeral State vs. App State in Flutter

Ephemeral State

App State

Examples of Application State:

No Clear-Cut Rules

Overview of Popular Flutter State Management Approaches

1. setState()

Pros:

Cons:

2. Provider

Pros:

Cons:

3. Riverpod

Pros:

Cons:

4. Bloc

Pros:

Cons:

5. GetX

Pros:

Cons:

Factors to Consider When Choosing a Flutter State Management Approach

1. Project Complexity

2. Team Expertise

3. Performance Requirements

4. Maintainability

5. Community Support and Ecosystem

Case Studies/Examples of FSM

Example 1: Small App Using setState() - To-Do List App

Why setState()?

Example 2: Medium-Sized App Using Provider or GetX - E-commerce App

Why Provider or GetX?

Example 3: Large-Scale App Using Bloc or Riverpod - Social Media App

Why Bloc or Riverpod?

Decision-Making Framework

Project Complexity:

Team Experience:

Performance Requirments:

Long-Term Maintainability:

Community and Ecosystem Support:

Common Pitfalls and How to Avoid Them

1. Overcomplicating Simple Projects

2. Disregard Performance Influence

3. Lack of Consistency

FAQ Section for Flutter State Management

Conclusion

Further Reading/Resources:

Example 1: Small App Using `setState()` - To-Do List App

Why `setState()`?