react-use/docs/useMeasure.md
2020-01-12 17:55:39 +01:00

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# `useMeasure`
React sensor hook that tracks dimensions of an HTML element using the [Resize Observer API](https://developer.mozilla.org/en-US/docs/Web/API/ResizeObserver).
## Usage
```jsx
import { useMeasure } from "react-use";
const Demo = () => {
const [ref, { x, y, width, height, top, right, bottom, left }] = useMeasure();
return (
<div ref={ref}>
<div>x: {x}</div>
<div>y: {y}</div>
<div>width: {width}</div>
<div>height: {height}</div>
<div>top: {top}</div>
<div>right: {right}</div>
<div>bottom: {bottom}</div>
<div>left: {left}</div>
</div>
);
};
```
This hook uses [`ResizeObserver` API][resize-observer], if you want to support
legacy browsers, consider installing [`resize-observer-polyfill`][resize-observer-polyfill]
before running your app.
```js
if (!window.ResizeObserver) {
window.ResizeObserver = (await import('resize-observer-polyfill')).default;
}
```
## Related hooks
- [useSize](./useSize.md)
[resize-observer]: https://developer.mozilla.org/en-US/docs/Web/API/ResizeObserver
[resize-observer-polyfill]: https://www.npmjs.com/package/resize-observer-polyfill