startTransition

React's startTransition API is a feature designed to help manage non-urgent UI updates. It allows developers to wrap state updates that are not critical to the user's immediate interaction in a transition. This tells React that these updates can be interrupted if a more urgent update, like typing into a text field, occurs.

When a state update is marked as a transition, React can de-prioritize it. This means that if the user performs an action that requires a more immediate response, React will pause the transition update and handle the urgent update first. Once the urgent update is complete, React will resume and finish the transition update. This prevents the UI from feeling janky or unresponsive during potentially long-running or complex rendering tasks.

The primary benefit of startTransition is improved user experience. By ensuring that user interactions feel instant and responsive, applications become more fluid and enjoyable to use. It is particularly useful for features like filtering large lists, navigating between different views, or rendering complex data visualizations where updates might take a noticeable amount of time.

To use startTransition, you wrap the state update that you want to be considered a transition within the `startTransition` function. For example, `startTransition(() => { setSearchQuery(value); });`. This signals to React that the `setSearchQuery` update can be a transition. It does not change the value of the state itself, but rather how React prioritizes rendering based on that state change.