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

class App extends React.Component {
  constructor(props) {
    super(props);

    this.state = { userInput: '', output: '' };
    this.handleUserInput = this.handleUserInput.bind(this);
  }

  handleUserInput(e) {
  	if (e.key === 'Enter') {
    	this.setState({output: e.target.value});
    }
  }
  
  handleChange(e) {
  	this.setState({userInput: e.target.value});
  }

  render() {
    return (
       <div>    
          <input 
           type="text" 
           value={this.state.userInput}
           onKeyPress={this.handleUserInput}
           onChange={this.handleChange}
           />
          <h1>{this.state.output}</h1>
       </div>      
     );
  }
}

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