Deep analysis of new features in React 18: concurrent rendering and suspension

React 18 is one of the most important versions in React history, introducing revolutionary features such as concurrent rendering, automatic batching, and suspension. This article will delve into the principles and application scenarios of these new features.
Concurrent Rendering
Concurrent rendering is a core feature of React 18, which allows React to be interrupted during the rendering process and prioritize handling more important updates. This greatly enhances the user experience, especially when dealing with large amounts of data.
working principle
React 18 uses time slicing technology to break down rendering work into small chunks that are executed during the browser's idle time. When there are higher priority tasks, React pauses the current rendering and prioritizes handling urgent tasks.
Enable concurrency feature using creatRoot
Automatic Batching
React 18 has expanded the scope of batch processing, and now state updates in Promise, setTimeout, and native event handlers are automatically batched to reduce unnecessary re rendering.
In React 18, these updates will be batch processed
Enhancement of Suspension
Suspense in React 18 not only supports code splitting, but also data retrieval. By incorporating new concurrency features, a smoother loading experience can be created.
New Hooks
useId
Used to generate unique IDs, especially suitable for server-side rendering scenes
useTransition
Used to mark non emergency updates and let React know which updates can be interrupted.
Migration Guide
Upgrading from React 17 to React 18 is relatively simple, but there are a few points to note:
Replace ReactDOM.render with creatRoot
Check the compatibility of third-party libraries
Test dual calling in Strict Mode
Gradually adopting new features without the need for a one-time rewrite
Performance optimization suggestions
By utilizing the new features of React 18, we can achieve better performance optimization:
Use useTransition to handle non emergency updates
Reasonably use Suspension for code segmentation
Utilize the interruptible feature of concurrent rendering
Cooperate with useMemo and usecallbacks to reduce unnecessary calculations
summary
The concurrency feature of React 18 brings new possibilities for front-end development. By making reasonable use of these features, we can build a smoother and more responsive user interface. Although there is a learning curve, in the long run, these investments are worthwhile.