webflow - session cleanup hook

[tak]

Hi,

   I had a question about session cleanup and dumping abandoned sessions.  We're looking at our shopping cart flow and thought it might be useful for us to analyze abandoned flows.  Is there a hook that we can use to tie into a "preCleanup" method and perhaps save/dump some pertinent info right before the session gets garbage collected?

Some web searching yielded:

http://stackoverflow.com/questions/6749505/spring-webflow-cleanup-on-httpsession-invalidation

http://stackoverflow.com/questions/2714176/spring-webflow-in-grails-keeping-plenty-of-hibernate-sessions-open

The FlowExecutionListener sounds interesting...

But those posts make it seem like it isnt quite what we're looking for. 

If we really can't do a "preCleanup" call, we could do the inverse (log everything somewhere on state transition, delete stuff that completes), but I thought I'd ask if theres a more straightforward approach.

-tak