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://fb.me/react-with-addons-15.2.0.js"></script>
<script src="https://fb.me/react-dom-15.2.0.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 P = React.createClass({
      render: function() {
      	var onlyChild = React.Children.only(this.props.children);
        var clone = React.cloneElement(onlyChild, { ref: "test" });
        return <div>Parent<br/>
        	{clone}
        </div>;
      },
      
      componentDidMount: function(prevProps, prevState) {
      	ReactDOM.findDOMNode(this.refs["test"]).style.backgroundColor="green";
      }
    });
    
    var C = React.createClass({
      render: function() {
        return <div>{this.props.text}</div>;
      }
    });
    
    ReactDOM.render(
      <P>
      <C text="a"/>
      </P>,
      document.getElementById('container')
    );