var Photo = React.createClass({

​

  toggleLiked: function() {

    this.setState({

      liked: !this.state.liked

    });

  },

​

  getInitialState: function() {

    return {

      liked: false

    }

  },

​

  render: function() {

    var buttonClass = this.state.liked ? 'active' : '';

​

    return (

      <div className='photo'>

        <img src={this.props.src} />

​

        <div className='bar'>

          <button onClick={this.toggleLiked} className={buttonClass}>

            ♥

          </button>

          <span>{this.props.caption}</span>

        </div>

      </div>

    )

  }

});

​

React.render(<Photo src='http://tinyurl.com/lkevsb9' caption='New York!'/>, document.body);