Fixing the React Native Component Update Issue

Discover how to solve the frequent issue of components in `React Native` not updating immediately after calculations. Follow our detailed guide for a smooth development experience.
---
This video is based on the question https://stackoverflow.com/q/71655151/ asked by the user 'Rafael Pertence' ( https://stackoverflow.com/u/3701240/ ) and on the answer https://stackoverflow.com/a/71655248/ provided by the user 'Phil' ( https://stackoverflow.com/u/283366/ ) 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: React Native components don't update as soon as they calculate

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.
---
Fixing the React Native Component Update Issue: A Step-by-Step Guide

When working with React Native, developers often run into various challenges. One such common problem is when components don't update as soon as they finish their calculations. Instead, they lag behind, updating all at once after all calculations complete, which can lead to a frustrating user experience. In this guide, we’ll address this problem and guide you through a solution using a clear, structured approach.

Understanding the Problem

In the provided component structure, there are two main issues contributing to the update delay:

Synchronous Sleep Function: The sleep function used in the original code blocks the main thread, preventing any updates from being visible until the calculations are complete.

Component Redefinition: Defining the Item component inside the Teste component means that every time Teste rerenders, Item is redefined, leading to inefficient performance.

Let’s dive into how we can resolve these issues effectively.

The Solution

1. Move the Item Component Outside

The first step to improving the situation is to move the Item component outside of the Teste component. This ensures that it does not get redefined on every render, reducing unnecessary performance overhead.

2. Implement a Promise-Based sleep Function

Next, we replace the blocking synchronous sleep function with a promise-based version. This allows the main thread to continue running while waiting for the calculation to finish, which makes state updates effective and visible immediately after completion.

Here's how to implement these changes:

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

Explanation of the Changes:

Promise-based sleep: By using a promise, we ensure that our component continues to function while the delay is happening.

Cancellation Function: The cancel function allows for cleaning up the timer if the Item component unmounts, preventing potential memory leaks or unexpected errors.

Conclusion

In summary, by moving the Item component outside of Teste and replacing the synchronous sleep function with a promise-based approach, we can ensure that each component updates individually as expected, greatly improving the performance and user experience of our React Native application.

If you've faced similar issues or have other questions about React Native, feel free to share your thoughts in the comments below. Happy coding!