[React] React Router: IndexRoute

IndexRoute allows us to define a default child component to be rendered at a specific route when no other sub-route is available.

When Home page display, we also make About component as default Route to dsiplay, only when use click Contact link, then swith to Contact Route:

import React from 'react';
import {hashHistory, Route, Router, Link, IndexRoute} from 'react-router';

const Home = (props) => <div><h1>Home</h1><Links></Links>{props.children}</div>;
const About = () => <div><h1>About</h1></div>;
const Contact = () => <div><h1>Contact</h1></div>;

const Links = () =>
    <nav >
        <Link activeStyle={{color: 'green'}} to="/">Home</Link>
        <Link activeClassName="active" to="/contact">Contact</Link>
    </nav>;

class App extends React.Component {
    render(){
        return(
            <Router history={hashHistory}>
                <Route path="/" component={Home}>
                    <IndexRoute component={About}></IndexRoute>
                    <Route path="contact" component={Contact}></Route>
                </Route>
            </Router>
        );
    }
}

export default App;