Return server updated row without reloading whole table

I have a dhtmlxgrid whose rows I sometimes update upon insertion in the server-side php script (through a beforeProcessing function).

After I update in a beforeProcessing function a row to be inserted, the corresponding SQL table is correctly updated with the new row containing the data added in the beforeProcessing. That works as intended thus.

Unfortunately, the data sent back to the client reads as:

<?xml version='1.0' ?>

this is the same data as when I simply insert a row (without modifying in the beforeProcessing function).

This is annoying since I would like to get the value in the client (a dhtmlxgrid).

Is it possible to force the dataprocessor to be a bit more verbose in its reponse and send the content of the whole row that was inserted (and modifying in the beforeProcessing function) ? (Not the whole table, just the row.) A flag that may be set in the beforeProcessing function?

There is no built-in logic for such kind of operation ( we have it in plans )
You can put a bit more code in beforeProcessing, something like

$action->set_response_attribute("newvalue", $newvalue);

on client side you can use onAfterUpdate event of dataprocessor

dp.attachEvent("onAfterUpdate", function(id, action, tid, tag){
     var newvalue = tag.getAttribute("newvalue");
     grid.cells(id, 1).setValue(newvalue);