Change tree only on changing parent of dragging node

[brusherru]

I need to use drag-n-drop feature only to change parents of nodes, not sorting (because all nodes will be sorted in alphabetic or another order that can be defined by user). And I think it's a common case of the use of tree view. So it would be great if there will be an option, that will:

• onDragEnd revert tree state into old state if dragging node didn't change his parent (so node will be placed to its place) and call onChange
• (optional) make draggable placeholder appears only inside other folders (nodes that can be parents)

Maybe someone already solved this issue and can share the solution?
Thanks!