> > The way I try to answer these sorts of questions for myself > > is to ask how things would work in "real life". > > ok, I think this is where I'm gettin' screwed up a bit. I'm > thinking how would it work in real life? You'd have your cart > full of items, roll it up to the checkout counter (an > object), the cashier removes all the items *from* the cart > and adds them up there on the counter. Then adds shipping, > asks for payment info, etc. > > So as I'm thinking it through, I'm thinking cart and checkout > are two separate things/objects. > > I understand what you're saying but still kinda mixed up on > how it should work.
I agree, these things aren't immediately obvious. But there are some objects that are significant to your model, and some that aren't. Before you start writing any code, you have to figure out the significant objects within your model, and how they will interact. For example, in a shopping model, you have customers, items to buy, and carts. Customers select items, and place them in their cart (or take them out). Customers purchase the contents of their cart. You want your model to be as simple as possible - but no simpler! If you come from a procedural background, like I do, it's worth pointing out that your objects will mainly be derived from the things you store within your database. In a shopping cart example, within your database you'll store information about customers, items, orders, and lineitems. Customers and items objects within your application might be derived directly from your database, while cart objects are essentially orders and lineitems (before the order is placed, of course). Dave Watts, CTO, Fig Leaf Software http://www.figleaf.com/ Fig Leaf Software provides the highest caliber vendor-authorized instruction at our training centers in Washington DC, Atlanta, Chicago, Baltimore, Northern Virginia, or on-site at your location. Visit http://training.figleaf.com/ for more information! ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~| Message: http://www.houseoffusion.com/lists.cfm/link=i:4:233634 Archives: http://www.houseoffusion.com/cf_lists/threads.cfm/4 Subscription: http://www.houseoffusion.com/lists.cfm/link=s:4 Unsubscribe: http://www.houseoffusion.com/cf_lists/unsubscribe.cfm?user=89.70.4 Donations & Support: http://www.houseoffusion.com/tiny.cfm/54
