Save siblings position

I want to save and load siblings position/order in database using dhtmlx php connector. what should I do?

Item index is not processed by Connector. However, DataProcessor sends an item index in “tr_order” parameter.

So, you need to set onUpdate event that will save an item position (“tr_order” parameter) after drag-and-drop: … ex_updates

and also you need to add sorting by the order field: … or:sorting