React Slide up and Slide down animation - CSS Transtion Group

Implement React Slide up and down animation via CSSTransitionGroup

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

.panel {
    width: 200px;
    background: green;
    margin-top: 10px;
    max-height: 0px;
    overflow: hidden;
    transition: max-height 0.5s ease;
}
.panel.visible{
  max-height:1000px;
}

.example-enter {
    height: 0px;
}

.example-enter.example-enter-active {
    height: 100px;
    -webkit-transition: height .3s ease;
}

.example-leave.example-leave-active {
    height: 0px;
    -webkit-transition: height .3s ease;
}

JavaScript 1.7

const CSSTransitionGroup = React.addons.CSSTransitionGroup;
const TransitionGroup = React.addons.TransitionGroup;

class Example extends React.Component{
    constructor(props) {
        super(props);
        this.state = { visible: 'panel' };
        this.handleClick = this.handleClick.bind(this)
    }

    handleClick() {
    	this.setState({ visible: this.state.visible == 'panel'? 'panel visible' : 'panel' });
    }

    render() {
        return <div>
            <button onClick={this.handleClick}>{!this.state.visible == 'panel' ? 'Slide up' : 'Slide down'}</button>
            	<div className={this.state.visible}>
              	<p>This is some dynamic content!</p>
                <p>Lorem ipsum dolor sit amet, consetetur sadipscing elitr, sed diam nonumy eirmod tempor invidunt ut labore et dolore magna aliquyam erat, sed diam voluptua. At vero eos et accusam et justo duo dolores et ea rebum. Stet clita kasd gubergren, no sea takimata sanctus est Lorem ipsum dolor sit amet. Lorem ipsum dolor sit amet, consetetur sadipscing elitr, sed diam nonumy eirmod tempor invidunt ut labore et dolore magna aliquyam erat, sed diam voluptua. At vero eos et accusam et justo duo dolores et ea rebum. Stet clita kasd gubergren, no sea takimata sanctus est Lorem ipsum dolor sit amet.</p>
              </div>
        </div>
    }
}

React.render(<Example />, document.getElementById('container'));