La división de Javascript en varios archivos se denomina división de paquetes. Esto le permite cargar solo el código que utiliza actualmente la aplicación, otras partes se cargan según sea necesario (a petición del usuario).
«» (lazy loading) :
Webpack
() . :
import { useState } from 'react' function MainComponent() { const [isModalDisplayed, setModalDisplayed] = useState(false) const [ModalComponent, setModalComponent] = useState(null) const loadModalComponent = async () => { const loadResult = await import('./components/Modal.js') setModalComponent(() => loadResult.default) } return ( <div> {isModalDisplayed && ModalComponent ? <ModalComponent /> : null} <button onClick={() => { setModalDisplayed(true) loadModalComponent() }} > Load Modal Component </button> </div> ) }
. Webpack
. , .
(microfrontend).
2. Split API React-
fusion-react
split
, - :
«»
React-, .
import { Link, Switch, Route } from 'react-router-dom' import { split } from 'fusion-react' const Loading = () => <div>Loading...</div> const Error = () => <div>Error</div> const Hello = split({ load: () => import('./components/hello.js'), Loading, Error, }) const Root = () => ( <> <div> <ul> <li> <Link to='/'>Home</Link> </li> <li> <Link to='/hello'>Hello</Link> </li> </ul> </div> <Switch> <Route path='/' exact component={Home} /> <Route path='/hello' component={Hello} /> </Switch> </> )
— , .
, — .
split
Hello
, . load
.
.
. .: React-, , react-loadable
react-lazyload
.
3. « » (vendor bundle)
, , ? , () , , . .
node_modules
:
const path = require('path') module.exports = { entry: path.resolve(__dirname, 'src/index.js'), output: { path: path.resolve(__dirname, 'dist'), filename: '[name].[contenthash].js', }, }
(yarn build
npm run build
), - :
⬡ webpack: Build Finished ⬡ webpack: assets by status 128 KiB [emitted] asset 935.js 124 KiB [emitted] [minimized] (id hint: vendors) 2 related assets asset main.js 3.24 KiB [emitted] [minimized] (name: main) 1 related asset asset index.html 267 bytes [emitted] assets by status 7.9 KiB [compared for emit] asset main.css 7.72 KiB [compared for emit] (name: main) 1 related asset asset 34.js 187 bytes [compared for emit] [minimized] 1 related asset Entrypoint main 135 KiB (326 KiB) = 935.js 124 KiB main.css 7.72 KiB main.js 3.34 KiB 3 auxiliary assets ... webpack 5.5.0 compiled successfully in 4856 ms
4.
, .
, ?
, React
, , .
Webpack
optimization
, :
module.exports = { splitChunks: { chunks: 'async', cacheGroups: { default: { minChunks: 2, reuseExistingChunk: true, }, vendor_react: { test: /.*\/node_modules\/react\/index\.js/, name: 'vendor-react', chunks: 'initial', enforce: true, }, }, }, }
client-vendor.js
clietn-vendor-react.js
.
5. React.lazy()
React.lazy()
— , .
:
import MyComponent from './MyComponent'
React.lazy()
:
const OtherComponent = React.lazy(() => import('./OtherComponent')
, React.lazy()
, Suspense
, (, ) :
import { lazy, Suspense } from 'react' const OtherComponent = lazy(() => import('./OtherComponent')) function MyComponent() { return ( <> <Suspense fallback={<div>Loading...</div>}> <OtherComponent /> </Suspense> </> ) }
fallback
(). Suspense
«» .
Suspense
, :
import { lazy, Suspense } from 'react' const OtherComponent = lazy(() => import('./OtherComponent')) const AnotherComponent = lazy(() => import('./AnotherComponent')) function MyComponent() { return ( <> <Suspense fallback={<div>Loading...</div>}> <section> <OtherComponent /> <AnotherComponent /> </section> </Suspense> </> ) }
, , , . , , , .
, , , .
, JavaScript-, , .
10% !