title: Django CMS: Custom plugin preview in editor escaping some characters
body: <p>I made a custom plugin for Django CMS, and as is the default behavior, the preview icon of the text field showed the returned value of the model's <code>__unicode__(self)</code> as the icon in the WYSIWYG view of the editor:</p>
  
  <p><img src="https://i.stack.imgur.com/00NSx.png" alt="&quot;Test email&quot;"></p>
  
  <p>(where "Email address" is the name of the custom plugin.) However, if the <code>__unicode__(self)</code> method of the plugin returns anything with characters such as <code>'</code>, <code>&amp;</code>, or <code>&lt; &gt;</code>, they get escaped in the preview:</p>
  
  <p><img src="https://i.stack.imgur.com/PeZly.png" alt="&quot;Test person&amp;#39"></p>
  
  <p>I'm pretty sure the preview uses the alt text property of the plugin instance. The closest thing to people having the same issue I can find is <a href="https://github.com/divio/django-cms/issues/1159" rel="nofollow noreferrer">this report</a>, as well as <a href="https://github.com/hpoul/django-cms/commit/b1e1d981d16edc3f3dfaaa5123bbfbfb78e9e029" rel="nofollow noreferrer">this suggested fix</a>, but neither solution causes any change in the alt text behavior, as far as I can tell.</p>
  
  <p>Basically, even though the plugin's output on the actual page isn't affected, I'd like to be able to display characters like <code>'</code>, <code>&amp;</code>, <code>&lt;</code>, and <code>&gt;</code>in the editor preview. Is this possible?</p>