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-15.0.1.js"></script>
<script src="https://fb.me/react-dom-15.0.1.js"></script>
<script src="https://facebook.github.io/react/js/jsfiddle-integration-babel.js"></script>

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

JavaScript 1.7

var Wrapper = React.createClass({
  render: function() {
  	var numFlatChildren = React.Children.toArray(this.props.children).length
    
    return (
    	<div>
        <div>
        	Number of flattened Children:
        	{numFlatChildren}
        </div>
        
        <div>
        	Children:
      		{this.props.children}
        </div>
      </div>
  	)
  }
});

var Root = React.createClass({
  render: function() {
    return (
    	<Wrapper>
    		<div id='one'> one
          <div id='two'> two
            <div id='three'> three
              <div id='four'> four
              </div>
            </div>
          </div>
        </div>
    	</Wrapper>
    )
  }
});

ReactDOM.render(
  <Root />,
  document.getElementById('root')
);