var React = require('react')  var ReactDOM = require('react-dom')    // import component  var FileInput = require('./src/fileInput')    var App = React.createClass({        getInitialState: function () {          return {              files: []          }      },        onChange: function (files) {          this.setState({              files: this.state.files.concat(files)          })      },        render: function () {          return (              <div>                  <FileInput onChange={this.onChange} multiple={false} />                  {this.state.files.length ?                  <div className="thumb-box">                      {// using files}                  </div> : null}              </div>          )      }    })    ReactDOM.render(      <App />,      document.querySelector(mountNode)  )