👀 Views: 0 💬 Answers: 1 📅 Created: 2025-07-08

reactjs useLayoutEffect performance javascript

Can someone help me understand I'm migrating some code and I've looked through the documentation and I'm still confused about I'm facing a performance issue with a component that utilizes `useLayoutEffect` in React 18... The component is supposed to measure its dimensions and adjust its layout accordingly. However, I'm experiencing layout thrashing, causing visible flickering when the component mounts and updates. Here's a simplified version of my code: ```javascript import React, { useLayoutEffect, useRef, useState } from 'react'; const MyComponent = () => { const ref = useRef(null); const [size, setSize] = useState({ width: 0, height: 0 }); useLayoutEffect(() => { const updateSize = () => { if (ref.current) { setSize({ width: ref.current.offsetWidth, height: ref.current.offsetHeight, }); } }; updateSize(); window.addEventListener('resize', updateSize); return () => window.removeEventListener('resize', updateSize); }, []); return <div ref={ref} style={{ width: size.width, height: size.height }}>Content here</div>; }; ``` The flickering seems to happen particularly when resizing the window. I have tried switching to `useEffect`, but that causes layout to not update as expected, leading to other issues. I've also tried debouncing the resize event to limit how often `updateSize` is called, but it hasn't resolved the flickering. I am using React 18 with ReactDOM 18 and the latest version of my browser. Is there a recommended pattern or optimization I can implement to handle this better? Any insights on avoiding layout thrashing while using `useLayoutEffect` would be greatly appreciated! This is part of a larger application I'm building. The stack includes Javascript and several other technologies. I'm open to any suggestions. How would you solve this?