maybe you could call a function periodically
a:poll or smth. might help
but I am not sure, if calling such a function really extends the session - just try it
I'm using a4j:poll just to send a request periodically (interval = 20 minutes). This request does nothing, cause it's intended just to keep the user's session "active".
Well, I don't know if it's the best solution, but if someone knows a better one, please tell me :)