[Seaside-dev] how to discern request?

[Sebastian Sastre]

hi seasiders,
I need a hint on how to be able to discern when a request is going to produce an
action phase or a render phase.
I don't see testing methods in WARequest to ask this. How can I deduct what is
going to happen?
thanks,
sebastian 
PD: the applicability of this is interesting: I want to know if the transaction
filter needs to commit or can use a read only transaction