@rehooks/component-size

> React hook for determining the size of a component

> Note: This is using the new React Hooks API Proposal
> which is subject to change until React 16.7 final.
>
> You'll need to install react, react-dom, etc at ^16.7.0-alpha.0

Install

``sh
yarn add @rehooks/component-size
`

Usage

`js
import { useRef } from 'react'
import useComponentSize from '@rehooks/component-size'

function MyComponent() {
let ref = useRef(null)
let size = useComponentSize(ref)
// size == { width: 100, height: 200 }
let { width, height } = size
let imgUrl = https://via.placeholder.com/${width}x${height}

return (



)
}
`

ResizeObserver

Resize Observer
is the API is used to determine if an element is resized. Browser support is pretty good in Chrome, but is still missing support in other major browsers.

> Can i use ResizeObserver?

$3

You can import the
polyfill directly from here

`sh
yarn add resize-observer-polyfill
`

Then import it in your app:

`js
import 'resize-observer-polyfill'
`

If you are using Webpack (or similar) you could use dynamic
imports, to load the
Polyfill only if needed. A basic implementation could look something like this:

`js
loadPolyfills()
.then(() => / Render React application now that your Polyfills are ready /)

/**
* Do feature detection, to figure out which polyfills needs to be imported.
**/
function loadPolyfills() {
const polyfills = []

if (!supportsResizeObserver()) {
polyfills.push(import('resize-observer-polyfill'))
}

return Promise.all(polyfills)
}

function supportsResizeObserver() {
return (
'ResizeObserver' in global &&
'ResizeObserverEntry' in global &&
'contentRect' in ResizeObserverEntry.prototype
)
}
``