Do Something About Sessions And Caching

[jtickle]

1. Create a SessionManager and a CacheManager.
2. egrep -r SESSION|GLOBALS *
3. Go through every single line of output and fix it so it is either using the SessionManager, the CacheManager, or neither.
4. Create a MiniAdmin link to "Clear Session" and another link to "Clear Cache".

The rule of thumb for session vs cache is like so: if it is something that needs to persist for a SPECIFIC user, put it on the session. No, wait, let me be more clear than that. Put only some kind of reference to an object on the session, like the User ID of who is logged in or some such.

If it's something that CAN persist for ALL users, put it on whatever cache is selected. Put the User ID on the session, but put that user object on the cache.

The good news is that we can use the static Layout and Current_User classes to act as a facade to the new interface pretty easily, so that's nice.

Regarding the user interface: even though "Clear Session" should log me out, it may not be a bad idea to put my user ID back on the session after it is reset. But I think that the User ID is the one magic thing that does not get cleared off of the session - anything else should know how to reload itself if necessary. Maybe I am wrong about that.

┆Issue is synchronized with this Asana task

[Stardog]

Good plan. Moving to 1.8.2 however so we can concentrate on 1.8.1 being stable. This is a rather largish change.

[Stardog]

BTW, there is a session class in the Global directory. It is handling the session start in 1.8.2. Please review and suggest improvements.

[Stardog]

I have updated comments for the Session class.

[jlbooker]

We should discuss a Session class that better wraps the $_SESSION so that modules cannot read/write/orverwrite other module's values. This will mean not using the magic __get and __set methods, and making an easy way for modules to get a reference to the Session system.