title: expression inside ng-class
body: <p>I have a very simple Angular App and I'm trying to use ng-repeat in conjunction with ng-class to repeat a template and apply a different class to the outer div depending on one of the properties of the data being bound.</p>
  
  <p>this worked when I used a simple...</p>
  
  <pre><code>ng-class="message.type"
  </code></pre>
  
  <p>...but unfortunately I need to concatenate a string to the start of the message type.</p>
  
  <p>I tried to create a JSfiddle here...</p>
  
  <p><a href="http://jsfiddle.net/XuYGN/5/">http://jsfiddle.net/XuYGN/5/</a></p>
  
  <p>... but it's my first attempt at making a JSfiddle too and I must be doing something wrong because the Angular stuff doesn't seem to be running. It does show what I'm trying to do with the expression though.</p>
  
  <p>Any help would really be appreciated.</p>