Investigating Performance Bottlenecks in React Components with Memoization and useCallback
I've been banging my head against this for hours. I just started working with Quick question that's been bugging me - Currently developing a dashboard application using React 17, and I've noticed significant lag when rendering a list of data fetched from the server. The list is dynamic, containing components that update frequently based on user interaction. I attempted to optimize my components with memoization, but the performance still doesn’t meet our standards. Here's a snippet of how I'm currently rendering the list: ```javascript const DataList = ({ items }) => { return ( <ul> {items.map(item => ( <ListItem key={item.id} {...item} /> ))} </ul> ); }; ``` I tried implementing `React.memo` on `ListItem`, expecting it to prevent unnecessary re-renders. However, the performance didn’t improve much. Here's how I applied it: ```javascript const ListItem = React.memo(({ name, details }) => { return <li>{name} - {details}</li>; }); ``` Additionally, I wrapped my `onClick` handlers in `useCallback`, but it seems like the entire `DataList` still re-renders every time the parent component's state updates. The parent component looks like this: ```javascript const ParentComponent = () => { const [state, setState] = useState({}); const handleClick = useCallback(() => { // some logic to update state }, []); return <DataList items={data} />; }; ``` I also verified that the `items` array reference isn’t changing unless there's an actual update, but the performance issues persist when the user interacts with the dashboard. What strategies can I employ to improve the rendering performance of `DataList` and `ListItem`? Are there particular patterns or configurations you’d recommend for handling such scenarios in React? Any debugging tips would also be appreciated. I'm working on a web app that needs to handle this. For reference, this is a production application. Thanks in advance! My team is using Javascript for this desktop app. Is there a simpler solution I'm overlooking? Any examples would be super helpful.