How to use the useResizeObserver hook for tracking element size changes in Next.js

In Next.js, you can use the useResizeObserver hook to track changes in the size of an element. This hook is not specific to Next.js and can be used in any React application. Here's how you can use it:

1. Install Dependencies:

Ensure you have the necessary dependencies installed. You'll need react and resize-observer-polyfill. If you're using Next.js, you likely already have react installed.

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npm install resize-observer-polyfill

2. Create the Hook:

Create a file (e.g., useResizeObserver.js) where you'll define the useResizeObserver hook:

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import { useEffect, useRef, useState } from 'react';

function useResizeObserver() {
  const [dimensions, setDimensions] = useState(null);
  const observerRef = useRef(null);

  useEffect(() => {
    observerRef.current = new ResizeObserver(entries => {
      const entry = entries[0];
      if (entry) {
        setDimensions(entry.contentRect);
      }
    });

    return () => {
      if (observerRef.current) {
        observerRef.current.disconnect();
      }
    };
  }, []);

  function observe(element) {
    if (observerRef.current) {
      observerRef.current.observe(element);
    }
  }

  return [observe, dimensions];
}

export default useResizeObserver;

3. Use the Hook:

Now, you can use this hook in your Next.js components to track element size changes. Here's an example:

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import { useRef } from 'react';
import useResizeObserver from './useResizeObserver';

function MyComponent() {
  const targetRef = useRef(null);
  const [observe, dimensions] = useResizeObserver();

  // Call the observe function with the target element
  useEffect(() => {
    if (targetRef.current) {
      observe(targetRef.current);
    }
  }, [targetRef.current, observe]);

  return (
    <div ref={targetRef}>
      {/* Your content */}
    </div>
  );
}

export default MyComponent;

In this example, MyComponent renders a div element with a ref attached to it. When the component mounts, it calls the observe function returned by the useResizeObserver hook with the div element as an argument. This sets up the observer to track size changes on that element. The dimensions variable holds the current dimensions of the observed element. You can use these dimensions in your component logic as needed.