在 Webpack 1 中主要是由bundle-loader进行懒加载,而 Webpack 2 中引入了类似于 SystemJS 的System.import语法,首先我们对于System.import的执行流程进行简单阐述:
而 React Router 路由的懒加载实际上分为动态路由与与懒加载两步,典型的所谓动态路由配置如下:
/** ** * * * * */ export default { path: '/', component: Core, indexRoute: { getComponent(location, cb) { ... }, }, childRoutes: [ { path: 'about', getComponent(location, cb) { ... }, }, { path: 'users', getComponent(location, cb) { ... }, }, { path: '*', getComponent(location, cb) { ... }, }, ], };
正常打包
import IndexPage from './views/app.jsx' import AboutPage from './views/about.jsx' export default function({history}) { return () }
这是一个正常打包的路由写法, 如果需要分割代码, 我们需要改造下路由, 借助getComponent和require.ensure
webpack 代码分割
export default function({history}) { return () } { require.ensure([], function(require) { callback(null, require('./HomePage.jsx')) }) }} /> { require.ensure([], function(require) { callback(null, require('./AboutPage.jsx')) }) }} />
这样看来代码有点累, 我们稍微改造下
const home = (location, callback) => { require.ensure([], require => { callback(null, require('./HomePage.jsx')) }, 'home') } const about = (location, callback) => { require.ensure([], require => { callback(null, require('./AboutPage.jsx')) }, 'about') } export default function({history}) { return () }
这样看起来是不是简洁了很多
注意: 由于webpack的原因, 如果直接require('./AboutPage.jsx')不能正常加载, 请尝试require('./AboutPage.jsx').default
webpack2 代码分割
上面的代码看起来好像都是webpack1的写法, 那么webpack2呢?
webpac2就需要借助System.import了
export default function({history}) { return () } { System.import('./HomePage.jsx').then(compOnent=> { callback(null, component.default || component) }) }} /> { System.import('./AboutPage.jsx').then(compOnent=> { callback(null, component.default || component) }) }} />
我们一样可以把上面的代码优化一下
const home = (location, callback) => { System.import('./HomePage.jsx').then(compOnent=> { callback(null, component.default || component) }) } const about = (location, callback) => { System.import('./AboutPage.jsx').then(compOnent=> { callback(null, component.default || component) }) } export default ({ history }) => { return () }
webpack2 + dva 实现路由和 models 懒加载
const routerThen = (app, callback, [component, model]) => { app.model(model.default || model) callback(null, component.default || component) } export default ({ history, app }) => { return () } { Promise.all([ System.import('./views/app.jsx'), System.import('./models/topics') ]).then(routerThen.bind(null, app, callback)) }} /> { Promise.all([ System.import('./views/article.jsx'), System.import('./models/topic') ]).then(routerThen.bind(null, app, callback)) }} />
以上就是本文的全部内容,希望对大家的学习有所帮助,也希望大家多多支持。