[Seaside] Update an image with AJAX/Comet (server push)

[Lukas Renggli]

> Can anybody explain this strange behavior? Or does someone have another idea
> how I can update an image with server push (without user input or site
> reload)? I would be very very happy to get some new ideas! - It's an
> important part of my master thesis..

In the first case (when you press the button) you are in the context
of a session, thus the application is also know. In the second case
the application is not know, presumably because you call the method
from some background thread.

Probably you could avoid the error by somehow faking a session so that
the URL could be generated the usual way. Alternatively you could
register the URL yourself with your application object by navigation
through the dispatcher to the application.

Hope this helps,
Lukas

-- 
Lukas Renggli
http://www.lukas-renggli.ch