title: Best solution for drag/drop category/subcategory? Tried jQuery UI sortable, now stuck
body: <p>I have a very crude category list right now, but I'm wanting it to make it look and behave more like WordPress admin does it, where you can drag a category into another category.</p>
  
  <p><img src="https://i.stack.imgur.com/FBbQ4.png" alt="categories"></p>
  
  <p>Code looks like this:</p>
  
  <pre><code>&lt;ul class="categories"&gt;
      &lt;li&gt;Real Estate&lt;/li&gt;
      &lt;li&gt;Home Improvements&lt;/li&gt;
      &lt;ul class="categories"&gt;
          &lt;li&gt;Interior&lt;/li&gt;
          &lt;li&gt;Exterior&lt;/li&gt;
          &lt;ul class="categories"&gt;
              &lt;li&gt;Exterior Subcat&lt;/li&gt;
          &lt;/ul&gt;
      &lt;/ul&gt;
  &lt;/ul&gt;
  </code></pre>
  
  <p>I tried jQuery UI's sortable, and told it to sort <code>&lt;li&gt;</code>'s only, but the list items wouldn't drag outside of their parent <code>&lt;ul&gt;</code> list into another <code>&lt;ul&gt;</code> list.</p>
  
  <p>Any ideas how I can accomplish this?</p>