title: How to manipulate attributes from ref selector
body: <p>I'd like to add a <code>disabled</code> attribute to the element that has <code>ref="formButton"</code>, I tried this and it didn't seem to work:</p>
  
  <pre><code>React.findDOMNode(this.refs.formButton).attr('disabled')
  this.refs.formButton.attr('disabled')
  </code></pre>