title: ng-src: show a throbber before an image is loaded
body: <p>I have implemented an interface where the user can cycle through a set of images by clicking buttons. The image URLs are stored in an array and are replaced by angular.js dynamically:</p>
  
  <pre><code>&lt;img ng-src="{currentUrl}"&gt;
  </code></pre>
  
  <p>However, the requests for consecutive images tend to lag a bit and the image change isn't apparent since the previous image is displayed until the new one arrives.</p>
  
  <p>I would like to replace the image with a throbber (animated gif). How can I achieve that using Angular.js?</p>