详解react-router4 异步加载路由两种方法

import React, { Component } from 'react'

export default class Bundle extends React.Component {

  state = {
    // short for "module" but that's a keyword in js, so "mod"
    mod: null
  }

  componentWillMount() {
    this.load(this.props)
  }

  componentWillReceiveProps(nextProps) {
    if (nextProps.load !== this.props.load) {
      this.load(nextProps)
    }
  }

  load(props) {
    this.setState({
      mod: null
    })
    props.load((mod) => {
      this.setState({
        // handle both es imports and cjs
        mod: mod.default ? mod.default : mod
      })
    })
  }

  render() {
    if (!this.state.mod)
      return false
    return this.props.children(this.state.mod)
  }
}

// ...

// bundle模型用来异步加载组件
import Bundle from './bundle.js';

// 引入单个页面（包括嵌套的子页面）
// 同步引入
import Index from './app/index.js';
// 异步引入
import ListContainer from 'bundle-loader?lazy&name=app-[name]!./app/list.js';

const List = () => (
  <Bundle load={ListContainer}>
    {(List) => <List />}
  </Bundle>
)

// ...

  <HashRouter>
    <Router basename="/">
      <div>
        <Route exact path="/" component={Index} />
        <Route path="/list" component={List} />
      </div>
    </Router>
  </HashRouter>

// ...


webpack.config.js文件配置
output: {
  path: path.resolve(__dirname, './output'),
  filename: '[name].[chunkhash:8].bundle.js',
  chunkFilename: '[name]-[id].[chunkhash:8].bundle.js',
},

output: {
  path: path.join(__dirname, '/../dist/assets'),
  filename: 'app.js',
  publicPath: defaultSettings.publicPath,
  // 添加 chunkFilename
  chunkFilename: '[name].[chunkhash:5].chunk.js',
},

ReactDOM.render(
 (
  <Router history={browserHistory}>
   {/* 主页 */}
   <Route path="/" component={App}>
    {/* 默认 */}
    <IndexRoute component={HomePage} />

    {/* baidu */}
    <Route path="/baidu" component={BaiduPage}>
     <Route path="result" component={BaiduResultPage} />
     <Route path="frequency" component={BaiduFrequencyPage} />
    </Route>

    {/* 404 */}
    <Route path='/404' component={NotFoundPage} />
    
    {/* 其他重定向到 404 */}
    <Redirect from='*' to='/404' />
   </Route>
  </Router>
 ), document.getElementById('app')
);

ReactDOM.render(
 (
  <Router history={browserHistory}>
   {/* 主页 */}
   <Route path="/" component={App}>
    {/* 默认 */}
    <IndexRoute component={HomePage} />

    {/* baidu */}
    <Route path="/baidu"
　　　　　　　　　　getComponent(nextState, cb) 
　　　　　　　　　　{ require.ensure([], (require) => { cb(null, require('components/layer/HomePage')) }, 'HomePage')}>
     <Route path="result"   getComponent... />
     <Route path="frequency" getComponent... />
    </Route>
    {/* 404 */}
    <Route path='/404' getComponent... />
    {/* 其他重定向到 404 */}
    <Redirect path='*' onEnter: (_, replaceState) => replaceState(null, "/404") />
   </Route>
  </Router>
 ), document.getElementById('app')
);

require.ensure(dependencies, callback, chunkName)

module.exports = {
 path: '*',
 onEnter: (_, replaceState) => replaceState(null, "/404")
}

getComponent(nextState, cb) {
  require.ensure([], (require) => {
   // 在后面加 .default
   cb(null, require('components/layer/ReportPage')).default
  }, 'ReportPage')
}