title: Jquery ui.draggable - how to get data attribute from a div
body: <p>HTML allows to put some data into an attribute. In the following example, the key of the data is "myval", the value is 10, the attribute name becomes data-myval :</p>
  
  <pre><code>&lt;div id="mydiv" data-myval="10" class="myclass"&gt;&lt;/div&gt;
  </code></pre>
  
  <p>Jquery getter : </p>
  
  <pre><code>var a = $('#mydiv').data('myval'); 
  </code></pre>
  
  <p>Jquery setter : </p>
  
  <pre><code>$('#mydiv').data('myval',20);
  </code></pre>
  
  <p>My question : when i drag and drop this div, i get his class, but i cannot get the data-myval attribute.  All thr var below are undefined :</p>
  
  <pre><code>drop : function( event, ui ){
  var drag = ui.draggable;
  var temp2 = drag.find("div").attr("data-myval");
  var temp3 = ui.draggable.attr('data-myval');
  var temp4 = ui.draggable.data('myval');
  var temp5 = $(ui.draggable).data('myval');
  </code></pre>
  
  <p>Update : i think the cloned node which is dragged, has only class and style attribute, all the other attributes are removed by Jquery.</p>
  
  <p>Any idea ?</p>