fires before a dragged element is released over the droppable area

boolean onBeforeDrop(object context,Event native_event);
contextobjectthe drag-n-drop context
native_eventEventan HTML event object
booleanreturning false will prevent further drag-and-drop processing


some.attachEvent("onBeforeDrop", function(context, native_event){
    //... some code here ... 
    // return false to block operation
    return true;

Related samples


If you drag multiple items, the event will be called once for the entire batch of items.

The drag-and-drop context can have the following properties:

  • from - the source object
  • to - the target object
  • source - the ID of the dragged item(s)
  • target - the ID of the drop target, null for drop on empty space
  • start - the ID from which drag-n-drop was started
  • index - (number) the index of the node within the branch
  • parent - (string,number) the ID of the branch
  • x_offset - the left offset between the pointer and the dragged element
  • y_offset - the top offset between the pointer and the dragged element
See also
Back to top
If you have not checked yet, be sure to visit site of our main product Webix widget library and page of javascript tree visualization product.