PHP and MySQL Web Development 4th Ed-tqw-_darksiderg

826 Chapter 33 Connecting to Web Services with XML and SOAP
Finally, we come to the main event-handling loop. A summary of the possible actions
is shown in Table 33.2.
Table 33.2
Action
Possible Actions in the Main Event Loop
Description
browsenode
detail
image
search
addtocart
deletefromcart
emptycart
showcart
Shows books in the specified category.This is the default action.
Shows the details of one particular book.
Shows a large version of the book’s cover.
Shows the results of a user search.
Adds an item to the user’s shopping cart.
Deletes an item from the shopping cart.
Empties the shopping cart altogether.
Shows the contents of the cart.
As you can see, the first four actions in this table relate to retrieving and displaying information
from Amazon.The second group of four deals with managing the shopping cart.
The actions that retrieve data from Amazon all work in a similar way. Let’s consider
retrieving data about books in a particular browsenode (category) as an example.
Showing Books in a Category
The code executed when the action is browsenode (view a category) is as follows:
showCategories($mode);
$category = getCategoryName($browseNode);
if(!$category || ($category=='Best Selling Books')) {
echo "Current Best Sellers";
} else {
echo "Current Best Sellers in ".$category."";
}
The showCategories() function displays the list of selected categories you see near the
top of most of the pages.The getCategoryName() function returns the name of the current
category given its browsenode number.The showBrowseNode() function displays a
page of books in that category.
Let’s begin by considering the showCategories() function.The code for this function
is shown in Listing 33.5.