React offers various hooks to efficiently manage state and side effects. One such hook, introduced in React 18, is useTransition, which enhances UI responsiveness. It allows developers to handle state updates in a non-blocking manner, ensuring smoother performance and a better user experience.
What is the useTransition Hook ?
The useTransition hook is a built-in React hook that helps defer state updates by marking them as low-priority. This means that high-priority updates, like user interactions, remain smooth, while other updates can wait for a more optimal time to execute.
Syntax
const [isPending, startTransition] = useTransition();
isPending: A boolean that indicates whether the transition is still pending.
startTransition: A function that wraps the state update to mark it as a transition.
Example: Using useTransition for List Filtering
We have a App component that renders the ItemsList component. To effectively demonstrate useTransition, we generate a large list of items with the help pf generateLargeList function and pass it as a prop to ItemsList.
The ItemsList component receives the items prop and displays them inside a <ul> element.It also includes an input field for filtering the list dynamically.Within ItemList,we maintain two state variables:
One for storing the input field’s value.Another for managing the filtered list of items.After setting up and running the application, you’ll notice a lag in the input field updates.The typed values don’t appear instantly because the UI is blocked while rendering the filtered list of items
Let’s address this issue with the help of useTransitionhook
As you can see, we’ve now imported the useTransition hook. Using startTransition, we mark filteredItems as a low-priority update, ensuring smoother UI interactions. Additionally, isPending returns a boolean value, indicating whether a transition is in progress. This can be used to display a loading indicator while the filtering process is happening.
Now, the input field updates instantly without any lag,asstartTransition ensures that filtering happens in the background.Once the filtering process is complete, the UI updates smoothly without blocking user interactions.
When to Use useTransition?
You should consider using useTransition in the following cases:
- Filtering Large Data: Ensuring smooth typing experience while filtering data in the background.
- Rendering Heavy Components: Deferring complex re-renders while keeping the UI responsive.
- Optimizing UI Performance: Preventing lag in interactive components.
Conclusion
The useTransition hook is a powerful tool for improving UI responsiveness by deferring non-urgent updates. By marking updates as transitions, React can prioritize user interactions, making applications feel smoother and more performant. If you're dealing with slow UI updates due to expensive renders, useTransition can be a great solution.
That’s it for now! Thanks for reading. See you in the next post!
Top comments (0)