In React, quick rendering and updating of components are crucial for creating smooth and responsive user experiences. Using batch updates is one technique to improve performance.
In this blog, we will look at what batch updates are, why they are important, and how to use them successfully in your React apps.
The React Rendering Process
React uses a virtual DOM and a reconciliation algorithm to efficiently update the UI. When the state changes, React determines which components need to be re-rendered and performs the necessary updates. However, performing immediate updates for every state change can be inefficient.
Understanding Batch Updates
Batch updates are a mechanism in React that allows multiple state updates to be grouped and processed in a single rendering cycle.
By batching updates, React can optimize the rendering process and minimize unnecessary re-renders, resulting in improved performance and a better user experience. With that out of the way, let's get started learning about batch updates.
Triggering Batch Updates
React automatically batches updates in certain scenarios, such as event handlers and lifecycle methods. By default, when you call setState multiple times within the same event handler or lifecycle method, React batches those updates together to optimize performance.
React does this for us in case of Synthetic Events and in case of hooks as well, until and unless we aren’t calling state updates inside any async function.
Here is a demonstration of it:
React performs a single re-rendering of the component, applying all three state updates simultaneously.
React, on the other hand, does not batch update when setState calls are made in any async methods or native event handlers.
React does not automatically batch updates in the scenarios of async methods like setTimeout, and Promise.
So when you call setState multiple times within the same handler, React renders its components every time.
The following example is for setTimeout
If you see the above example each setState will render the component you can see the console value.
By utilizing batch updates, React avoids unnecessary intermediate renders and ensures that the component is updated only once, even though two state updates were performed in quick succession. This optimization leads to better performance and a smoother user experience.
If you are using React 18, you do not need to worry about batch updates because the batch updates feature is built-in for async methods.
However, if you are using React 17 or earlier versions, you may need to view this. Inside of promises, setTimeout, native event handlers, or any other event were not batched in React by default.
Remember, batching updates is not just about performance optimization, it also leads to better usability and responsiveness, making your applications more enjoyable for users.
Conclusion
Efficiently managing updates in React is crucial for building high-performance applications. By leveraging batch updates, you can significantly improve the rendering process, reduce unnecessary re-renders, and deliver a smoother user experience. Understanding the principles and techniques discussed in this article will empower you to optimize your React components and create fast and responsive web applications.
That concludes this topic. Thank you for reading!
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