title: What is Uncaught TypeError: Cannot read property 'open' of undefined for AppBar + Drawer component (ReactJS + Material-UI)?
body: <p>I am attempting to get the navigation, default hamburger icon on the left of AppBar ( <a href="http://www.material-ui.com/#/components/app-bar" rel="nofollow">http://www.material-ui.com/#/components/app-bar</a> ) from Material-UI framework to slide open the Drawer component when clicked ( <a href="http://www.material-ui.com/#/components/drawer" rel="nofollow">http://www.material-ui.com/#/components/drawer</a> ). But once clicked, I am getting the following error and I can't see to figure out: </p>
  
  <p>Uncaught TypeError: Cannot read property 'open' of undefined</p>
  
  <p>Any insight or guidance on it would be greatly appreciated. Thank you in advance.    </p>
  
  <pre><code>import React, { Component } from 'react'
  import { Drawer, AppBar, MenuItem} from 'material-ui'
  import baseTheme from 'material-ui/styles/baseThemes/lightBaseTheme'
  import getMuiTheme from 'material-ui/styles/getMuiTheme'
  import { Route, Router } from 'react-router'
  
  
  
  export default class Main extends Component  {
  
    constructor(props, context){
      super(props, context);
      this.state = {open:false};
    }
  
    getChildContext() {
      return {muiTheme: getMuiTheme(baseTheme)};
    }
  
    handleToggle() {
      this.setState({open: !this.state.open});
     }
  
          render() {
              return (
                  &lt;div&gt;
                  &lt;AppBar   
                    isInitiallyOpen={true} 
                    onLeftIconButtonTouchTap={this.handleToggle}        
                    onLeftIconButtonClick={this.handleToggle} 
                  /&gt;
  
                  &lt;Drawer
                    docked={false}
                    open={this.state.open}&gt;
                    &lt;MenuItem&gt;Menu Item 1&lt;/MenuItem&gt;
                    &lt;MenuItem&gt;Menu Item 2&lt;/MenuItem&gt;
                    &lt;MenuItem&gt;Menu Item 3&lt;/MenuItem&gt;
                  &lt;/Drawer&gt;
                  &lt;/div&gt;
              );
          }
      }
  
  export default Main;
  </code></pre>