var TIMER_COMPONENT = ("\nvar Timer = React.createClass({\n getInitialState: function() {\n return {secondsElapsed: 0};\n },\n tick: function() {\n this.setState({secondsElapsed: this.state.secondsElapsed + 1});\n },\n componentDidMount: function() {\n this.interval = setInterval(this.tick, 1000);\n },\n componentWillUnmount: function() {\n clearInterval(this.interval);\n },\n render: function() {\n return (\n
Seconds Elapsed: {this.state.secondsElapsed}
\n );\n }\n});\n\nReact.render(, mountNode);\n" ); React.render( React.createElement(ReactPlayground, {codeText: TIMER_COMPONENT}), document.getElementById('timerExample') );