Step 3: General Script Changes from Tutorial 2 - PHP

We’ve made a few changes since tutorial 2. A new library was added, a bunch of shopping related scripts, and more.

Now loads up the shopping cart library (lib/cart.php) and initializes the shopping cart if it hasn't already been initialized.

The index page now lists the on-special items on the right of the screen. You mark an item as being on special from the administrative product manager screens (which have also been modified to accomodate this new feature).

The products administration screen has been modified to handle the on-special flag. This is the first time we are dealing with checkboxes, they are wierd to deal with when processing HTML forms because they behave a bit differently from the other form input types. They are defined when checked, and undefined otherwise. This forces your scripts to check for the existence of form variable instead of checking for it's value.

This is a new administrative function to show the orders that have taken place on the system. It is a simple listings of the orders with the ability to see the order details.

Fixed a bug from part 2, every user you created got the password $password due to quoting problems. Thanks to the people who pointed it out :)

This file contains the declaration of the Cart class. If you are new to objects in PHP, take a moment to look at how it is written. The session variable $SESSION["cart"] is an instance of this Cart class.

Added some new functions:

• err2()
  Like the original err() function, except it prints the market >> instead of <<.
  
• get_category_tree()
  Returns the category navigation tree as a string.
  
• print_category_tree()
  Calls get_category_tree() and prints the result.
  
• get_cart_items()
  Returns a handler ($qid) of a database query with the id, name, and unit price of all the items in the shopping cart.
  
• chop_ccnum()
  Returns parts of a credit card number so that it is safe to display without giving out the customer's credit card number.
  
• save_orderinfo()
  Used in the order confirmation screen, this function saves the customer's order information (which includes contact information and credit card information) into the session temporarily.
  
• load_orderinfo()
  The counter part to save_orderinfo(), this will retrieve the customer's order information from the session.
  
• clear_orderinfo()
  Clears out the customer order information saved in the session, this is called once the orderinfo was successfully retrieved by load_orderinfo(). Together, these three functions are responsible for passing sensitive order information between the purchase and payment processing scripts.
Like the original err() function, except it prints the market instead of .Returns the category navigation tree as a string.Calls get_category_tree() and prints the result.Returns a handler () of a database query with the id, name, and unit price of all the items in the shopping cart.Returns parts of a credit card number so that it is safe to display without giving out the customer's credit card number.Used in the order confirmation screen, this function saves the customer's order information (which includes contact information and credit card information) into the session temporarily.The counter part to save_orderinfo(), this will retrieve the customer's order information from the session.Clears out the customer order information saved in the session, this is called once the orderinfo was successfully retrieved by load_orderinfo(). Together, these three functions are responsible for passing sensitive order information between the purchase and payment processing scripts.

The standard header template has been modified to show the shopping cart summary. So throughout the site, the user will always know their shopping cart summary.