[Seaside-dev] refactoring the session tracking code

[Philippe Marschall]

Hi

As discussed previously I'm not very happy with our current session
tracking code. Mainly due to how it is woven into
WARegistry/WAApplication. That makes it impossible to change without
subclassing WAApplication. There are several tracking schemes that we
don't support currently and are hard to do with the current code.

 - cookies only, I know some of our corporate "customers" want/need/do
this, they either need to change code or write custom code, it is
unfortunate that we don't support this out of the box
 - ssl session id based
 - ip based for crawlers [1]

The proposed refactoring is to move this functionality to a strategy
object responsible for extracting the session key from a request and
adding the session key to a response or action URL. This has some
overlap with the WARegistry/WAApplication refactoring that Julian is
doing but it should not be too hard to merge. The work would be done
in the WIP repository.

[1] http://www.tomcatexpert.com/blog/2011/05/18/crawler-session-manager-valve

Cheers
Philippe