React Newbies Guide: Learn How to Improve Your App’s Performance with useLayoutEffect

Are you looking to improve the performance of your React applications? Look no further than the useLayoutEffect hook.

useLayoutEffect is a hook that allows you to synchronously update the layout of a component before it is rendered on the screen. This can lead to smoother animations and better overall performance.

Here are the top two use cases for useLayoutEffect with code examples:

Measuring DOM elements

useLayoutEffect can be used to accurately measure the size and position of DOM elements, which is essential for creating smooth animations and responsive design. Here’s an example of how you can use useLayoutEffect to measure the width of a button and update the state of a component to change the font size of the text inside the button:

const [buttonWidth, setButtonWidth] = useState(0);

useLayoutEffect(() => {
  const buttonRef = useRef(null);
  setButtonWidth(buttonRef.current.getBoundingClientRect().width);
}, [buttonWidth]);

return (
  <button ref={buttonRef} style={{fontSize: `${buttonWidth/10}px`}}>
    Click me
  </button>
);

Updating State Based on Layout

useLayoutEffect can be used to update the state of a component based on the layout, which can be useful for creating dynamic layouts and responsive design. Here’s an example of how you can use useLayoutEffect to update the state of a component based on the width of the window and change the number of items displayed in a grid:

const [gridColumns, setGridColumns] = useState(3);

useLayoutEffect(() => {
  const handleResize = () => {
    if (window.innerWidth < 600) {
      setGridColumns(1);
    } else if (window.innerWidth < 900) {
      setGridColumns(2);
    } else {
      setGridColumns(3);
    }
  };
  window.addEventListener('resize', handleResize);
  return () => window.removeEventListener('resize', handleResize);
}, [gridColumns]);

return (
  <Grid columns={gridColumns}>
    {/* items */}
  </Grid>
);

In conclusion, useLayoutEffect is a powerful tool for improving the performance of React applications. Whether you’re measuring DOM elements, or updating state based on layout, useLayoutEffect can help you achieve your goals. So, don’t wait any longer, start experimenting with useLayoutEffect today and take your React skills to the next level!”