onBeforeDrag

fires before the mouse button is pressed and the cursor is moved over a draggable item

boolean onBeforeDrag(object context,Event native_event);

context	object	the drag-n-drop context
native_event	Event	an HTML event object

boolean

returning false will prevent dragging of the element

Example

grida.attachEvent("onBeforeDrag", function(context, native_event){
    context.html = "<div style='padding:8px;'>";
    for (var i=0; i< context.source.length; i++){
        context.html += context.from.getItem(context.source[i]).title + "<br>" ;
    }
    context.html += "</div>";
    return true;
});

Related samples

Details

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 dropping 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