"since your last visit" quandary

[Donny Bahama]

Application is a simple message board. Each time the user returns I want to show a message stating the number of new posts since the last visit. But here's the catch - I want to retain that information for the user's entire session, only updating the "LastPost" datum at the end of the session.

Now, Determining which posts are new and storing the "LastPost" datum isn't the issue. That stuff I can handle. What I can't figure out is how to allow the user to continually refer back to the page that shows him the new posts since his last visit. Since the page is query driven and uses the "LastPost" datum as the filter criteria, I can't update the "LastPost" datum until I know the user is done with his session - - if I do, the query-driven page will show different data.

To put it another way, pseudocode would look something like this...

Code: Select all

If (visit=new) {
   //user is returning - this is a new visit
   get $last_post
   select count(*) from posts where id > $last_post
} elseif (visit=same) {
   //user is hitting this page again, but this is still the same visit
   get $last_post
   select count(*) from posts where id > $last_post
} else {
   //user left, end of visit
   set $last_post = (highest post id that existed while user was here.)
}

But how the heck do you do THAT?!

[grahame]

If you're using $_SESSION, why not store the "lastpost" data in there when a user starts a new session and refer back to that variable throughout the session, rather than going back to tha database each time?

[Donny Bahama]

I guess I'm a bit skittish wrt session vars. I only recently learned about them/how to use them and began using them, but I ran into so many problems... the sid would change when I posted a form, etc. Maybe I'm doing something wrong, I don't know. (Or maybe it's a Xampp issue and I won't have those problems once the pages are published.)

Your suggestion seems like the logical way to go about it, though. I'll give it a shot and see how it goes.

Thanks, Graham.