5.1. Designing the Shopping Cart

A Web application that allows you to purchase items online is called a shopping cart, named after the cart you push around the grocery store and fill with items to buy. The online purchasing application works in a similar manner, allowing you to put items into your shopping cart. However, the application does more than just provide a shopping cart that keeps track of the items you add. It collects the information it needs to complete the purchase, such as your address, and processes the order and your credit card order. It also must coordinate, or include, a catalog of products that are available for sale. Although it might be more technically correct to call the application an online ordering system, it's more commonly called just a shopping cart.

Shopping carts can be implemented in many ways. Your first task is to decide how to implement yours.

5.1.1. Making design decisions

You must make some fundamental programming design decisions before designing the user interface. Be sure to consider the following basics:

  • Customer login: Many stores require customers to register and log in before they can purchase products. Customer registration provides the store with information about its customers, such as phone numbers and e-mail addresses. Requiring login also allows for features that you can't provide without the login process. For instance, you can't provide a feature that allows customers to track their orders without requiring that the customer ...

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