How can I restrict shipping choices based on kinds of products in the cart?

[bladerogers]

OK, not sure if this is in the right topic, but hope I get some help here. I am attempting to modify the logic of the shopping cart shipping information. On a per product basis I have modified the products table to include two new boolean fields, one for canada post and one for UPS. When the user checksout I wish to check all cart items to see if which methods of shipping pertain to each and present to the user true totals as some of their orders may be split shipping (case in point, Canada Post will not ship Ammunition, only UPS will...user has 3 ammunition products in cart and another item that can go either or...we need to give the user the option to split this up). Anyhow, I'll deal with that later...for now my issue is this. I find tracking down the functions and methods somewhat difficult in Zen. Right now I am trying to determine what array element names exist in the array $product (foreach ($productArray as $product) ) which is used in the tpl_shoppingcartdefault file. Attempting to output array elements by key position does nothing $product[6] for instance). I've determined through a count that their are 19 positions in the array, but I need to know how to acccess each without knowing their element reference names!! I need the productid for each item in the array, and of course productid, product_id and the obvious don't seem to exist. In what file is the Session variable 'cart' created?? I can't seem to find that in the obvious places. Also, does there exist a dev manual for zen cart? Is there a way to view all current session variables at any given time, like a session var page??