title: React Js conditionally applying class attributes
body: <p>I want to conditionally show and hide this button group depending on what is passed in from the parent component which looks like this:</p>
  
  <pre><code>&lt;TopicNav showBulkActions={this.__hasMultipleSelected} /&gt;
  </code></pre>
  
  <p>....</p>
  
  <pre><code>__hasMultipleSelected: function() {
    return false; //return true or false depending on data
  }
  </code></pre>
  
  <p>....</p>
  
  <pre><code>var TopicNav = React.createClass({
  render: function() {
  return (
      &lt;div className="row"&gt;
          &lt;div className="col-lg-6"&gt;
              &lt;div className="btn-group pull-right {this.props.showBulkActions ? 'show' : 'hidden'}"&gt;
                  &lt;button type="button" className="btn btn-default dropdown-toggle" data-toggle="dropdown" aria-expanded="false"&gt;
                    Bulk Actions &lt;span className="caret"&gt;&lt;/span&gt;
                  &lt;/button&gt;
                  &lt;ul className="dropdown-menu" role="menu"&gt;
                    &lt;li&gt;&lt;a href="#"&gt;Merge into New Session&lt;/a&gt;&lt;/li&gt;
                    &lt;li&gt;&lt;a href="#"&gt;Add to Existing Session&lt;/a&gt;&lt;/li&gt;
                    &lt;li className="divider"&gt;&lt;/li&gt;
                    &lt;li&gt;&lt;a href="#"&gt;Delete&lt;/a&gt;&lt;/li&gt;
                  &lt;/ul&gt;
              &lt;/div&gt;
          &lt;/div&gt;
      &lt;/div&gt;
      );
    }
  });
  </code></pre>
  
  <p>Nothing is happening however, with the {this.props.showBulkActions ? 'show' : 'hidden'}. Am I doing anything wrong here?</p>