VbzCart/pieces/sessions

Technology: VbzCart: Sessions

Identifying Sessions

I've been debating about the idea of allowing carts to work using IP address/domain plus browser ID (user_agent) because cookies don't always seem to work (and some people have them turned off), and I think I've come up with a reasonable compromise.

The problem is that one user might connect through a dial-up (dynamic IP), place orders in a cart and disconnect, and then another user with the same browser and OS might happen to connect through the same dial-up -- which would cause that user to be assigned the previous user's shopping cart. This isn't a serious problem, because no personal information will be conveyed, but it can be off-putting to go to a store and find that your cart already has items in it. I would be inclined to immediately go somewhere else.

What I've come up with is the following:

• sessions IDed via IP/browser have a much shorter expiration than cookie sessions
• sessions IDed via IP/browser will show a warning to indicate the shorter expiration time (should show the time when the session will expire -- and the current time, to prevent timezone confusion)
• cookies have never been used for checkout; we have always used POST data (?session=xxxxx), so that's not an issue

Sequence of Events

• On receiving one or more items to add to the cart:
  • Try to match with existing session:
    • Check for session cookie; if found, use that
    • If no session cookie, look for unexpired IP/browser match
  • If no usable existing session found, create a new one (empty cart)
  • Add items to the session cart
  • Display cart & session info