I would like to send a parameter together with dp.sendData(), then access it in server (Java) code, in event handler like beforeUpdate(DataAction action)? This way, I don’t need to tamper with the grid itself.
You can set global userdata for the grid
grid.setUserData("", “some”, “value”);
and on server side , get it in the beforeUpdate as
action.get_value(some);
( also, it possible to include any custom parameters directly in dataprocessor’s url , used in client side dataProcessor constructor, but it will be a bit more problematic to retrieve such data on server side )