title: Fullcalendar: duplicate entry on dropping (external)
body: <p>I was using <a href="https://stackoverflow.com/questions/7159967/while-adding-events-to-fullcalendar-by-external-drag-and-drop-item-doesnt-get">while adding events to Fullcalendar by external drag and drop, item doesn&#39;t get id</a> to modify the dropped element (title, id and date) and get the callback in the drop function of the fullcalendar</p>
  
  <pre><code>var url = "json-save-urlaub.php?event="+date.format()+"&amp;allDay="+date.hasTime();
                      $.post(
                          url, 
                          function(data){ //callback function retrieving the response sent by the controller/action
                              //event is the object that will actually be rendered to the calendar
                              var event = jQuery.parseJSON(data);
                              //actually rendering the new event to the calendar
  
                              $('#calendar').fullCalendar('renderEvent', event, true);
  
                              //$('#calendar').fullCalendar('refetchEvents');
                              $('#calendar').fullCalendar('unselect');
                          }
                      );
  </code></pre>
  
  <p>However now I have two entries when I drop the element on the fullcalendar since the callback gives me a new event object and the one dropped I can't remove since it has no id and I can't remove it manually neither can I use it for the URL call. </p>
  
  <p>The line <code>$(this).remove();</code> has no effect. Neither has <code>$("#calendar").fullCalendar( 'removeEvents', copiedEventObject._id);</code> when copying the dropped element first. How can I just have one element when dropping it?</p>