React Base Fiddle (JSX)

Starting point for creating JSFiddles with React. This uses React with Addons.

HTML

<script src="https://cdnjs.cloudflare.com/ajax/libs/babel-core/5.8.24/browser.js"></script>
<script src="https://npmcdn.com/react@latest/dist/react-with-addons.js"></script>
<script src="https://npmcdn.com/react-dom@latest/dist/react-dom.js"></script>
<script src="https://facebook.github.io/react/js/jsfiddle-integration-babel.js"></script>

<div id="container">
    <!-- This element's contents will be replaced with your component. -->
</div>

JavaScript 1.7

var Hello = React.createClass({
	
  getInitialState: function() {
    return {
    	url: "https://dl.dropboxusercontent.com/u/4803975/Layer0_1.png",
    };
  },

  render: function() {
    const userBackgroundURL = this.state.url;

    return (
    	<div
        onClick={() => {
        	this.setState({url: "https://dl.dropboxusercontent.com/u/4803975/Layer1_0.png"});
        }}
    		style={{
        	height: 500,
          padding: 100,
    			backgroundImage: `url(http://www.codako.org/board-grid.png), url(${userBackgroundURL})`,
          backgroundSize: "40px, cover",
        }}
     	>
      	Click me to replace background and see issue!
     	</div>
    );
  }
});

ReactDOM.render(
  <Hello />,
  document.getElementById('container')
);