title: JsTree: changing the "open" icon for folders using the "types" plugin
body: <p>It's easy to specify what the icon should be for a closed folder using the "types" plugin. But can the types plugin also be used to specify what an <strong>open</strong> folder should look like, or can I only do this with CSS (like below) ?</p>
  
  <pre><code>li.jstree-open &gt; a .jstree-icon 
  {
      background:url("folder_open.png") 0px 0px no-repeat !important;
  } 
  </code></pre>