title: ng-switch on empty string
body: <p>I'm using Angular and I want to check when a string is empty using ng-switch. The following code doesn't seem to be working for me.</p>
  
  <pre><code>&lt;div ng-switch on="foo"&gt;
      &lt;span ng-switch-when=""&gt;This string is empty&lt;/span&gt;
      &lt;span ng-switch-default&gt;This string is not empty&lt;/span&gt;
  &lt;/div&gt;
  </code></pre>
  
  <p>Any help with this would be appreciated.</p>