Java GridConnector add row(s)

Is it possible to add more DataItem rows after render_table() or render_sql()?

It can be done on client side:

grid.load(url,function(){ grid.addRow(id,""); });

or

grid.load(url1,fucntion(){ grid.load(url2); });

Yes, it is clear how to add rows to grid in client but it would be very useful to be able to do that on a server side as well.
Thanks.

There is no way to call another render_sql() on the server side.