react-resize-detector
v11.0.1
Published
React resize detector
Downloads
5,706,183
Readme
Handle element resizes like it's 2024!
Live demo
Modern browsers now have native support for detecting element size changes through ResizeObservers. This library utilizes ResizeObservers to facilitate managing element size changes in React applications.
🐥 Tiny ~2kb
🐼 Written in TypeScript
🐠 Used by 170k repositories
🦄 Produces 100 million downloads annually
No window.resize
listeners! No timeouts!
Is it necessary for you to use this library?
Container queries now work in all major browsers. It's very likely you can solve your task using pure CSS.
<div class="post">
<div class="card">
<h2>Card title</h2>
<p>Card content</p>
</div>
</div>
.post {
container-type: inline-size;
}
/* Default heading styles for the card title */
.card h2 {
font-size: 1em;
}
/* If the container is larger than 700px */
@container (min-width: 700px) {
.card h2 {
font-size: 2em;
}
}
Installation
npm i react-resize-detector
// OR
yarn add react-resize-detector
Example
import { useResizeDetector } from 'react-resize-detector';
const CustomComponent = () => {
const { width, height, ref } = useResizeDetector();
return <div ref={ref}>{`${width}x${height}`}</div>;
};
With props
import { useResizeDetector } from 'react-resize-detector';
const CustomComponent = () => {
const onResize = useCallback(() => {
// on resize logic
}, []);
const { width, height, ref } = useResizeDetector({
handleHeight: false,
refreshMode: 'debounce',
refreshRate: 1000,
onResize
});
return <div ref={ref}>{`${width}x${height}`}</div>;
};
With custom ref
It's not advised to use this approach, as dynamically mounting and unmounting the observed element could lead to unexpected behavior.
import { useResizeDetector } from 'react-resize-detector';
const CustomComponent = () => {
const targetRef = useRef();
const { width, height } = useResizeDetector({ targetRef });
return <div ref={targetRef}>{`${width}x${height}`}</div>;
};
API
| Prop | Type | Description | Default |
| --------------- | ------ | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ----------- |
| onResize | Func | Function that will be invoked with width
, height
and ResizeObserver entry
arguments | undefined
|
| handleWidth | Bool | Trigger onResize
on width change | true
|
| handleHeight | Bool | Trigger onResize
on height change | true
|
| skipOnMount | Bool | Do not trigger onResize when a component mounts | false
|
| refreshMode | String | Possible values: throttle
and debounce
See lodash docs for more information. undefined
- callback will be fired for every frame | undefined
|
| refreshRate | Number | Use this in conjunction with refreshMode
. Important! It's a numeric prop so set it accordingly, e.g. refreshRate={500}
| 1000
|
| refreshOptions | Object | Use this in conjunction with refreshMode
. An object in shape of { leading: bool, trailing: bool }
. Please refer to lodash's docs for more info | undefined
|
| observerOptions | Object | These options will be used as a second parameter of resizeObserver.observe
method. | undefined
|
| targetRef | Ref | Use this prop to pass a reference to the element you want to attach resize handlers to. It must be an instance of React.useRef
or React.createRef
functions | undefined
|
Testing with Enzyme and Jest
Thanks to @Primajin for posting this snippet
const { ResizeObserver } = window;
beforeEach(() => {
delete window.ResizeObserver;
window.ResizeObserver = jest.fn().mockImplementation(() => ({
observe: jest.fn(),
unobserve: jest.fn(),
disconnect: jest.fn()
}));
wrapper = mount(<MyComponent />);
});
afterEach(() => {
window.ResizeObserver = ResizeObserver;
jest.restoreAllMocks();
});
it('should do my test', () => {
// [...]
});
License
MIT
❤️
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