Скачать или смотреть How to Effectively Manage State with RxDart in Flutter BLoC?

Discover the best practices for calling state management methods in Flutter BLoC using RxDart. Learn when to use initState versus build.
---
This video is based on the question https://stackoverflow.com/q/75021795/ asked by the user 'La Pyae' ( https://stackoverflow.com/u/9019910/ ) and on the answer https://stackoverflow.com/a/75022357/ provided by the user 'HW Kim' ( https://stackoverflow.com/u/10853095/ ) at 'Stack Overflow' website. Thanks to these great users and Stackexchange community for their contributions.

Visit these links for original content and any more details, such as alternate solutions, latest updates/developments on topic, comments, revision history etc. For example, the original title of the Question was: In which method, should call state management methods of the class in Flutter bloc with rxdart?

Also, Content (except music) licensed under CC BY-SA https://meta.stackexchange.com/help/l...
The original Question post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/... ) license, and the original Answer post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/... ) license.

If anything seems off to you, please feel free to write me at vlogize [AT] gmail [DOT] com.
---
Understanding State Management in Flutter BLoC with RxDart

Managing state in Flutter applications can present a unique set of challenges, particularly when leveraging various libraries and design patterns. One frequently asked question among developers is: In which method should I call state management functions in a Flutter BLoC using RxDart?

Many Flutter developers grapple with what appears to be conflicting advice regarding calling functions from a StatefulWidget. In this post, we’ll break down the issue and provide a comprehensive solution aimed at optimizing state management in a BLoC pattern with RxDart.

The Dilemma: initState vs. build

When working with a StatefulWidget, developers are divided on whether to execute state management methods inside the initState() method or the build() method. Here are the key elements of the debate:

initState(): This method is executed once when the state is initialized. Consequently, it is where you might want to set up your state management logic, particularly if you wish to perform an action only once when the widget is loaded.

build(): This method is called every time Flutter needs to render the widget. If you call state management methods here, it can lead to multiple executions, causing unnecessary rebuilds and performance issues.

Recommended Approach

Opt for Using initState

To better manage your state without redundant calls and performance pitfalls, it’s best to set up your BLoC logic in the initState() method. Here’s how you can implement it effectively:

[[See Video to Reveal this Text or Code Snippet]]

Explanation of the Code

Create a Bloc Instance: Use OtpLoginModuleProvider.of(context) within the build() method to access your instance of the BLoC.

Initialize Once: By implementing the countdown logic in a post-frame callback within initState(), we ensure that the countdown only starts once, minimizing unnecessary calls during widget rebuilds.

Dispose Resources: It’s crucial to implement cleanup procedures to prevent memory leaks. In your OtpLoginModuleBloc, do not forget to dispose of your streams and any active timers when your widget is disposed of:

[[See Video to Reveal this Text or Code Snippet]]

Summary

To summarize, the best practice for managing state in Flutter while using the BLoC pattern with RxDart is to initialize state management in initState() and fetch the BLoC within the build() method to ensure smooth performance. This allows your app to remain responsive without unnecessary state rebuilds.

Implement these strategies, and you’ll have a more efficient and readable codebase that adheres to the principles of effective state management in Flutter.

Happy coding!