title: Change jQuery draggable helper during drag
body: <p>I'm trying to make a draggable helper change based on the context of where the dragged element is (indicating you can drop the element there by changing the helper). </p>
  
  <p>I had two ideas in my mind: </p>
  
  <ol>
  <li><p>Declare the helper as a function, and return the appropriate helper. Unfortunately, the function is called only once, at the beginning of the drag.</p></li>
  <li><p>In the drag event, change the helper. This sounds like the best option. The problem is that I don't find how to change the helper to a specific DOM element (only accepted values are "clone", "original" and a function.</p></li>
  </ol>
  
  <p>Am I missing something or is this not possible ?</p>