aaa.js

import React from 'react'
import { render } from 'react-dom'
import { browserHistory, Router, Route, Link, withRouter} from 'react-router'

import withExampleBasename from '../withExampleBasename'

const App = React.createClass({
  render() {
    return (
      <div>
        <ul>
          <li><Link to="/dashboard" activeClassName="active">Dashboard</Link></li>
          <li><Link to="/form" activeClassName="active">Form</Link></li>
        </ul>
        {this.props.children}
      </div>
    )
  }
})

class ConfirmNavigation extends React.Component {

  componentWillMount() {

    this.props.router.setRouteLeaveHook(
      this.props.route,
      this.routerWillLeave
    )
  }


  routerWillLeave() {
      return 'You have unsaved information, are you sure you want to leave this page?'
  }

  render() {
    return null;
  }
}

const PreventFromLeaving = withRouter(ConfirmNavigation);



const Dashboard = React.createClass({
  render() {
    return <h1>Dashboard</h1>
  }
})

const Form = withRouter(
  React.createClass({


    getInitialState() {
      return {
        textValue: 'ohai'
      }
    },


    handleChange(event) {
      this.setState({
        textValue: event.target.value
      })
    },

    handleSubmit(event) {
      event.preventDefault()

      this.setState({
        textValue: ''
      }, () => {
        this.props.router.push('/')
      })
    },

    render() {
      return (
        <div>
          <form onSubmit={this.handleSubmit}>
            <p>Click the dashboard link with text in the input.</p>
            {<PreventFromLeaving route={this.props.route} />}
            <input type="text" ref="userInput" value={this.state.textValue} onChange={this.handleChange} />
            <button type="submit">Go</button>
          </form>
        </div>
      )
    }
  })
)

render((
  <Router history={withExampleBasename(browserHistory, __dirname)} routes={
    <Route path="/" component={App}>
        <Route path="dashboard" component={Dashboard} />
        <Route path="form" component={Form} />
      </Route>
    }>

  </Router>
), document.getElementById('example'))