javascript - React-router Webpack HMR。根路由必须渲染单个元素

Question

我试图弄清楚当 HMR 启用并卡在以下错误时，react-router 在 AppContainer 内如何工作。您能解释一下黑客攻击是怎么回事吗？

Invariant Violation: The root route must render a single element

Index.js

import React from 'react';
import ReactDOM from 'react-dom';

import { AppContainer } from 'react-hot-loader';
// AppContainer is a necessary wrapper component for HMR

import Routes from './routes/index';
const MOUNT_APP = document.getElementById('root');

const render = () => {
  ReactDOM.render(
    <AppContainer>
      <Routes />
    </AppContainer>,
    MOUNT_APP
  );
};

render();

// Hot Module Replacement API
if (module.hot) {
  module.hot.accept('./routes/index', () => {
    render()
  });
}

路由文件是:

import React from 'react';
import { Router, IndexRoute, browserHistory } from 'react-router';

import Home from './Home';
import SubView from './Sub';

const componentRoutes = {
  component   : Home,
  path        : '/',
  indexRoute  : SubView,
  childRoutes : [

  ]
}

const Routes = () => {
  return (
    <Router history={browserHistory} routes={componentRoutes} />
  );
};

export default Routes;

HomeView 组件:

import React from 'react';

const HomeView = () => {
    <div>
      <h4>Welcome</h4>
    </div>
}

export default HomeView;

HomeView路线:

import HomeView from './components/SubView';

export default {
  component: HomeView
}

PS:SubView 等于 HomeView。

Answer 1

您需要从组件返回一个元素。现在，您的 HomeView 组件如下所示:

const HomeView = () => {
    <div>
      <h4>Welcome</h4>
    </div>
}

您需要返回标记，而不是像这样将其放入函数体内:

const HomeView = () => {
    return (
         <div>
             <h4>Welcome</h4>
         </div>
    )
}