fires after drag-n-drop was finished
| context | object | the drag-n-drop context | 
| native_event | Event | the native event object | 
gridb.attachEvent("onBeforeDrop", function(context, native_event){
    for (var i=0; i< context.source.length; i++){
        context.from.copy(context.source[i],context.index,this,webix.uid());
    }
    return false;
});
 
some.attachEvent("onAfterDrop", function(context, native_event){
    //... some code here ... 
});
The drag-and-drop context can have the following properties: