What are the best practices for using React Concurrent Mode?

What are the best practices for using React Concurrent Mode?

When using React Concurrent Mode, it's important to focus on optimizing rendering performance and user experience. Here are some best practices:

1. Use Suspense: Leverage Suspense for data fetching to improve loading states.
2. Prioritize Updates: Use startTransition to mark updates that can be interrupted, allowing for smoother user interactions.
3. Avoid Blocking: Minimize blocking updates to keep the UI responsive.
4. Code Splitting: Implement code splitting to load components only when needed.
5. Profile Performance: Use React's built-in profiling tools to identify performance bottlenecks.

Can you explain how Suspense works in Concurrent Mode?

Sure! Suspense allows you to wait for some asynchronous operation to complete before rendering a component. In Concurrent Mode, it helps manage loading states more effectively. You can wrap components that fetch data in a <Suspense> component and provide a fallback UI, like a loading spinner, while the data is being fetched. This way, the UI remains responsive, and users get a better experience.

What is startTransition and how do I use it?

startTransition is a function that lets you mark updates as non-urgent. This means that React can interrupt these updates if more urgent updates, like user interactions, come in. To use it, you wrap your state updates in startTransition, like this:

import { startTransition } from 'react';

startTransition(() => {
  setState(newState);
});

This helps keep the UI responsive by allowing React to prioritize more important updates.

Are there any common pitfalls to avoid?

Yes, some common pitfalls include:

1. Overusing Suspense: Don't wrap every component in Suspense; use it judiciously.
2. Neglecting Performance Profiling: Always profile your app to catch performance issues early.
3. Blocking Updates: Avoid making updates that block the main thread, as this can lead to a poor user experience.