i mean, there's an api function in the LS javascript that let me pass the data it's just received to something else ?
all of our client libraries have some sort of events that are triggered when data is received (e.g.: with the javascript client has the NonVisualTable's callbacks, whjile with java you have the listener HandyTableListener). You have to implement the handling of such data to do your xml/db writing.
Obviously if you implement the protocol instead of using one of our client libraries you'll be able to trigger whatever you want upon reception of an update.