title: Add body class if class ".loading" active
body: <p>I am using the lazyload for a project, it loads images progressively.</p>
  
  <p><a href="https://github.com/verlok/lazyload" rel="nofollow noreferrer">https://github.com/verlok/lazyload</a></p>
  
  <p>When the images are loading, the "loading" class is activated in the <code>&lt;img class = "loading"&gt; ... &lt;/ img&gt;</code></p>
  
  <p>and when it finishes loading, the "loading" class is replaced by the class "loaded"</p>
  
  <p>I want to know if it would be possible to add a class to a div based on the activity of the "loading" class.</p>
  
  <p>I made a rather rustic example, just to demonstrate my goal.</p>
  
  <pre><code>if ($('img').hasClass('loading')) { 
  $("body").addClass("images-is-loading"); 
  $(".post-thumbnail").addClass("post-images-is-loading"); 
  }
  </code></pre>
  
  <p>Could someone clarify me? Thanks</p>