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/react/0.13.1/JSXTransformer.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/0.13.1/react-with-addons.js"></script>
<script src="https://facebook.github.io/react/js/jsfiddle-integration.js"></script>

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

CSS

span div {
    display:inline-block; 
    background: black; color: white; padding: 30px; font-size: 24px;
}

.transition{
  /*transition: opacity 1.5s ease-in;  */
  animation-name: myAnimation;
  animation-fill-mode: forwards;
  animation-duration: 3000ms;
        
}
.transition2{
  transition: opacity 0s ease-in; 
}

@keyframes myAnimation{
  0%{
    opacity: 1;

  }
  50%{
    opacity: 0.5;
  }
  100%{
    opacity: 0;
  }
}

.on {
  opacity: 1;
}

.off {
  opacity: 0;
}

JavaScript 1.7

var Hello = React.createClass({
    getInitialState: function() {
      return {on: true};
    },
    onClick: function() {
      this.setState({on: !this.state.on});
    },
    render: function() {
    var variant;
    if(this.state.on){
     variant = 'transition';
    } else {
     variant = 'transition';
    }
        var k = <div className={variant}> Hello {this.props.name} </div>
        return <div>
            <a href="#" onClick={this.onClick}> Click to toggle </a>
            <br/> <br/>
              <span>{k}</span>
          </div>;
    }
});
 
React.render(<Hello name="World" />, document.getElementById('container'));