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

Solution Overview
821
Listing 33.3
Continued
}
}
$$e = trim($$e);
// default values for global variables
if($mode=='') {
$mode = 'Books'; // No other modes have been tested
}
if($browseNode=='') {
$browseNode = 53; //53 is bestselling non-fiction books
}
if($page=='') {
$page = 1; // First Page - there are 10 items per page
}
//validate/strip input
if(!eregi('^[A-Z0-9]+$', $ASIN)) {
// ASINS must be alpha-numeric
$ASIN ='';
}
if(!eregi('^[a-z]+$', $mode)) {
// mode must be alphabetic
$mode = 'Books';
}
$page=intval($page); // pages and browseNodes must be integers
$browseNode = intval($browseNode);
// it may cause some confusion, but we are stripping characters out from
// $search it seems only fair to modify it now so it will be displayed
// in the heading
$search = safeString($search);
if(!isset($_SESSION['cart'])) {
session_register('cart');
$_SESSION['cart'] = array();
}
// tasks that need to be done before the top bar is shown
if($action == 'addtocart') {
addToCart($_SESSION['cart'], $ASIN, $mode);
}
if($action == 'deletefromcart') {
deleteFromCart($_SESSION['cart'], $ASIN);
}
if($action == 'emptycart') {
$_SESSION['cart'] = array();