react/examples/basic-click-counter/Index.html

<!DOCTYPE html>
<html>
  <head>
    <title>React click conter example</title>
    <meta http-equiv='Content-type' content='text/html; charset=utf-8'>
    <script src="../../build/react.js"></script>
    <script type="text/javascript">
    var Counter = React.createClass({
      getInitialState: function() {
        return { clickCount: 0 };
      },
      handleClick: function() {
        var selfClickNumber = this.state.clickCount;
        this.setState({clickCount: ++selfClickNumber});
      },
      render: function () {
        return React.DOM.h2({onClick: this.handleClick}, 'Count number: '+this.state.clickCount);
      }
    });
    </script>
  </head>
  <body>
    <div id="message" align="center"></div>

    <script type="text/javascript">
      React.render(
        React.createElement(Counter),
        document.getElementById('message')
      );
    </script>
  </body>
</html>