Is it possible to limit where an external item can be dropped to? For example, allowing an external item to be dropped only on the 5:00 to 6:00 slot. I realize it is possible to validate this server-side, but it would be nice to have it client-side as well.
The client-side validation is not implemented yet. Once it is, it will be general enough to work with external drag&drop as well.
Actually, there are three possible validation levels:
Server-side. That means a roundtrip to the server and possibly showing a message.
Client-side (after the event is dropped). This can already be done using EventMoveJavaScript (set EventMoveHandling="JavaScript"). Do you validation in the client-side handler and call the server if it's allowed using dpc.eventMoveCallBack().
Client-side (during drag). This is probably what you are asking for. This one has to be implemented as a new feature.
This question is more than 1 month old and has been closed. Please create a new question if you have anything to add.