<th>&nbsp;</th> </tr> {section name=cCart loop=$cart_details->mCartProducts} <tr> <td> <input name="productID[]" type="hidden" value="{$cart_details->mCartProducts[cCart].product_id}" /> {$cart_details->mCartProducts[cCart].name} </td> <td>${$cart_details->mCartProducts[cCart].price}</td> <td> <input type="text" name="quantity[]" size="10" value="{$cart_details->mCartProducts[cCart].quantity}" /> </td> <td>${$cart_details->mCartProducts[cCart].subtotal}</td> <td align="right"> <input type="button" name="saveForLater" value="Save for later" onclick="window.location= '{$cart_details->mCartProducts[cCart].save|prepare_link}';" /> <input type="button" name="remove" value="Remove" onclick="window.location= '{$cart_details->mCartProducts[cCart].remove|prepare_link}';" /> </td> </tr> {/section} </table> <table> <tr> <td class="cart_total"> <span>Total amount:</span>&nbsp; <span class="price">${$cart_details->mTotalAmount}</span> </td> <td class="cart_total" align="right"> <input type="submit" name="update" value="Update" /> </td> </tr> </table> </form> {/if} {if ($cart_details->mIsCartLaterEmpty == 0)} <br /> <span class="description">Saved products to buy later:</span> <br /><br /> <table> <tr> <th>Product Name</th> <th>Price</th> CHAPTER 8 ■ THE SHOPPING CART294 648XCH08.qxd 10/31/06 10:07 PM Page 294 <th>&nbsp;</th> </tr> {section name=cSavedCart loop=$cart_details->mSavedCartProducts} <tr> <td>{$cart_details->mSavedCartProducts[cSavedCart].name}</td> <td> ${$cart_details->mSavedCartProducts[cSavedCart].price} </td> <td align="right"> <input type="button" name="moveToCart" value="Move to cart" onclick="window.location= '{$cart_details->mSavedCartProducts[cSavedCart].move|prepare_link}';" /> <input type="button" name="remove" value="Remove" onclick="window.location= '{$cart_details->mSavedCartProducts[cSavedCart].remove|prepare_link}';" /> </td> </tr> {/section} </table> {/if} <br /> <input type="button" name="continueShopping" value="Continue Shopping" onclick="window.location='{$cart_details->mCartReferrer}';" /> 4. Add the following styles to hatshop.css: .cart_total { background: #ffffff; border: none; } You just finished the visitor’s part of the code for this chapter, so now it’s time to try it out and make sure everything works as expected. Test it by adding products to the shopping cart, changing the quantity, and removing items. How It Works: The Shopping Cart The actions that the shopping cart can execute are defined by the following constants defined in include/ config.php: ADD_PRODUCT, REMOVE_PRODUCT, UPDATE_PRODUCTS_QUANTITIES, SAVE_PRODUCT_ FOR_LATER, and MOVE_PRODUCT_TO_CART. Note that we didn’t define any variable for viewing the shopping cart, so if CartAction does not take any value or its value is not equal to one of the action variables, it will simply display the shopping cart content. Every shopping cart action, except viewing and updating the shopping cart, relies on the ProductID query string parameter (an error is raised if it isn’t set). If the proper conditions are met, the business tier method that corre- sponds to the visitor’s action is called. CHAPTER 8 ■ THE SHOPPING CART 295 648XCH08.qxd 10/31/06 10:07 PM Page 295 Administering the Shopping Cart Now that you’ve finished writing the shopping cart, there are two more things you need to take into account, both related to administration issues: • How to delete from the catalog a product that exists in shopping carts. • How to count or remove old shopping cart elements by building a simple shopping cart administration page. This is important because without this feature, the shopping_cart table keeps growing, filled with old temporary (and useless) carts. Deleting Products Residing in the Shopping Cart The catalog administration pages enable you to completely delete products from the catalog. Before removing a product, you should also remove its appearances in visitors’ shopping carts. Update the catalog_delete_product function from the hatshop database by following these steps: 1. Load pgAdmin III, and connect to the hatshop database. 2. Click Tools ➤ Query tool (or click the SQL button on the toolbar). A new query window should appear. 3. Use the query tool to execute this code, which updates the catalog_delete_product function from your hatshop database: Updates catalog_delete_product function CREATE OR REPLACE FUNCTION catalog_delete_product(INTEGER) RETURNS VOID LANGUAGE plpgsql AS $$ DECLARE inProductId ALIAS FOR $1; BEGIN DELETE FROM product_category WHERE product_id = inProductId; DELETE FROM shopping_cart WHERE product_id = inProductId; DELETE FROM product WHERE product_id = inProductId; END; $$; Building the Shopping Cart Admin Page The second problem with the shopping cart is that at this moment no mechanism exists to delete the old records from the shopping_cart table. On a high-activity web site, the shopping_cart table can grow very large. With the current version of the code, shopping cart IDs are stored at the client browser for seven days. As a result, you can assume that any shopping carts that haven’t been updated in the last ten days are invalid and can be safely removed. CHAPTER 8 ■ THE SHOPPING CART296 648XCH08.qxd 10/31/06 10:07 PM Page 296 In the following exercise, you’ll quickly implement a simple shopping cart administration page, where the administrator can see how many old shopping cart entries exist, and can delete them if he or she wants to. Figure 8-5 shows this page. Figure 8-5. Administering shopping carts The most interesting aspect you need to understand is the SQL logic that deletes all shop- ping carts that haven’t been updated in a certain amount of time. This isn’t as simple as it sounds—at first sight, you might think all you have to do is delete all the records in shopping_cart whose added_on is older than a specified date. However, this strategy doesn’t work with shopping carts that are modified over time (say, the visitor has been adding items to the cart each week in the past three months). If the last change to the shopping cart is recent, none of its elements should be deleted, even if some are very old. In other words, you should either remove all elements in a shopping cart or none of them. The age of a shopping cart is given by the age of its most recently modified or added product. This being said, implement the new functionality by following the exercise steps. Exercise: Creating the Shopping Cart Admin Page 1. Load pgAdmin III, and connect to the hatshop database. 2. Add the following data tier functions to the hatshop database: Create shopping_cart_count_old_carts function CREATE FUNCTION shopping_cart_count_old_carts(INTEGER) RETURNS INTEGER LANGUAGE plpgsql AS $$ DECLARE inDays ALIAS FOR $1; outOldShoppingCartsCount INTEGER; BEGIN SELECT INTO outOldShoppingCartsCount COUNT(cart_id) FROM (SELECT cart_id FROM shopping_cart CHAPTER 8 ■ THE SHOPPING CART 297 648XCH08.qxd 10/31/06 10:07 PM Page 297 GROUP BY cart_id HAVING ((NOW() - ('1'||' DAYS')::INTERVAL) >= MAX(added_on))) AS old_carts; RETURN outOldShoppingCartsCount; END; $$; Create shopping_cart_delete_old_carts function CREATE FUNCTION shopping_cart_delete_old_carts(INTEGER) RETURNS VOID LANGUAGE plpgsql AS $$ DECLARE inDays ALIAS FOR $1; BEGIN DELETE FROM shopping_cart WHERE cart_id IN (SELECT cart_id FROM shopping_cart GROUP BY cart_id HAVING ((NOW() - (inDays||' DAYS')::INTERVAL) >= MAX(added_on))); END; $$; 3. Add the following business tier method to business/shopping_cart.php: // Count old shopping carts public static function CountOldShoppingCarts($days) { // Build SQL query $sql = 'SELECT shopping_cart_count_old_carts(:days);'; // Build the parameters array $params = array (':days' => $days); // Prepare the statement with PDO-specific functionality $result = DatabaseHandler::Prepare($sql); // Execute the query and return the results return DatabaseHandler::GetOne($result, $params); } // Deletes old shopping carts public static function DeleteOldShoppingCarts($days) { // Build the SQL query $sql = 'SELECT shopping_cart_delete_old_carts(:days);'; // Build the parameters array $params = array (':days' => $days); // Prepare the statement with PDO-specific functionality $result = DatabaseHandler::Prepare($sql); CHAPTER 8 ■ THE SHOPPING CART298 648XCH08.qxd 10/31/06 10:07 PM Page 298 // Execute the query return DatabaseHandler::Execute($result, $params); } 4. Create a new file named presentation/smarty_plugins/function.load_admin_cart.php, and add the following code to it: <?php /* Smarty plugin function that gets called when the load_admin_cart function plugin is loaded from a template */ function smarty_function_load_admin_cart($params, $smarty) { // Create AdminCart object $admin_cart = new AdminCart(); $admin_cart->init(); // Assign template variable $smarty->assign($params['assign'], $admin_cart); } // Class that supports cart admin functionality class AdminCart { // Public variables available in smarty template public $mMessage; public $mDaysOptions = array (0 => 'All shopping carts', 1 => 'One day old', 10 => 'Ten days old', 20 => 'Twenty days old', 30 => 'Thirty days old', 90 => 'Ninety days old'); public $mSelectedDaysNumber = 0; // Private members public $_mAction = ''; // Class constructor public function __construct() { foreach ($_POST as $key => $value) // If a submit button was clicked if (substr($key, 0, 6) == 'submit') { // Get the scope of submit button $this->_mAction = substr($key, strlen('submit_'), strlen($key)); // Get selected days number if (isset ($_POST['days'])) CHAPTER 8 ■ THE SHOPPING CART 299 648XCH08.qxd 10/31/06 10:07 PM Page 299 $this->mSelectedDaysNumber = (int) $_POST['days']; else trigger_error('days value not set'); } } public function init() { // If counting shopping carts if ($this->_mAction == 'count') { $count_old_carts = ShoppingCart::CountOldShoppingCarts($this->mSelectedDaysNumber); if ($count_old_carts == 0) $count_old_carts = 'no'; $this->mMessage = 'There are ' . $count_old_carts . ' old shopping carts (selected option: ' . $this->mDaysOptions[$this->mSelectedDaysNumber] . ').'; } // If deleting shopping carts if ($this->_mAction == 'delete') { $this->mDeletedCarts = ShoppingCart::DeleteOldShoppingCarts($this->mSelectedDaysNumber); $this->mMessage = 'The old shopping carts were removed from the database (selected option: ' . $this->mDaysOptions[$this->mSelectedDaysNumber] .').'; } } } ?> 5. Create a new file in the presentation/templates folder named admin_cart.tpl, and type the following code: {* admin_cart.tpl *} {load_admin_cart assign='admin_cart'} <span class="admin_page_text">Admin users&#039; shopping carts:</span> <br /><br /> {if $admin_cart->mMessage neq ""} <span class="admin_page_text">{$admin_cart->mMessage}</span> <br /><br /> {/if} CHAPTER 8 ■ THE SHOPPING CART300 648XCH08.qxd 10/31/06 10:07 PM Page 300 <form action="{"admin.php?Page=Cart"|prepare_link:"https"}" method="post"> <span class="admin_page_text">Select carts</span> {html_options name="days" options=$admin_cart->mDaysOptions selected=$admin_cart->mSelectedDaysNumber} <input type="submit" name="submit_count" value="Count Old Shopping Carts" /> <input type="submit" name="submit_delete" value="Delete Old Shopping Carts" /> </form> 6. Modify presentation/templates/admin_menu.tpl by adding the highlighted link code to the cart admin page: <span class="menu_text"> | <a href="{"admin.php?Page=Cart"|prepare_link:"https"}">CART ADMIN</a> | <a href="{"admin.php"|prepare_link:"https"}">CATALOG ADMIN</a> | 7. Add the highlighted code that loads the admin_cart.tpl in admin.php: elseif ($admin_page == 'ProductDetails') $pageContentsCell = 'admin_product.tpl'; elseif ($admin_page == 'Cart') $pageContentsCell = 'admin_cart.tpl'; How It Works: The Shopping Cart Admin Page The hard work of the shopping cart admin page is done by the two functions you’ve added to the hatshop data- base: shopping_cart_count_old_carts and shopping_cart_delete_old_carts. They both receive as parameter the number of days that determine when a shopping cart is old, and they use the same logic to calcu- late the shopping cart elements that are old and should be removed. The age of a shopping cart is given by the age of the most recently added or changed item and is calculated using the GROUP BY SQL clause. The condition that establishes whether a cart should be considered old is the following: WHERE cart_id IN (SELECT cart_id FROM shopping_cart GROUP BY cart_id HAVING ((NOW() - (inDays||' DAYS')::INTERVAL) >= MAX(added_on))); Summary In this chapter, you learned how to store the shopping cart information in the database, and you learned a few things in the process as well. Probably the most interesting was the way you can store the shopping cart ID as a cookie on the client because you haven’t done anything similar so far in this book. CHAPTER 8 ■ THE SHOPPING CART 301 648XCH08.qxd 10/31/06 10:07 PM Page 301 After working through the process of creating the shopping cart, starting with the data- base and ending with the presentation tier, we also touched on the new administrative challenges. You’ll complete the functionality offered by the custom shopping cart in the next chapter with a custom checkout system. You’ll add a Place Order button to the shopping cart, which will allow you to save the shopping cart information as a separate order in the database. CHAPTER 8 ■ THE SHOPPING CART302 648XCH08.qxd 10/31/06 10:07 PM Page 302 Dealing with Customer Orders The good news is that your shopping cart looks good and is fully functional. The bad news is that it doesn’t allow the visitor to actually place an order, which makes the cart totally useless in the context of a production system. We’ll deal with that problem in this chapter in two separate stages. In the first part of the chapter, you’ll implement the client-side part of the order-placing mechanism. More precisely, you’ll add a Place Order button to the shopping cart control, which will allow the visitor to order the products in the shopping cart. In the second part of the chapter, you’ll implement a simple orders administration page where the site administrator can view and handle pending orders. The code for each part of the site will be presented in the usual way, starting with the data- base tier, continuing with the business tier, and finishing with the user interface (UI). Implementing an Order Placement System The entire order-placement system is related to the Place Order button mentioned earlier. Figure 9-1 shows how this button will look after you update the cart_details componentized template in this chapter. Figure 9-1. The shopping cart with a Place Order button 303 CHAPTER 9 648XCH09.qxd 11/17/06 3:39 PM Page 303 [...]... PP_OrderManagement_IntegrationGuide.pdf Now that you have an idea of what to do with that Place Order button, the next major concerns are what order information to store in the database and how to store it As you saw in previous chapters, deciding how to store information helps you get a better idea of how the whole system works Storing Orders in the Database Two kinds of order information need to be stored: • General details about the... structure and relationships The orders Table The orders table contains two categories of information: data about the order itself (the first six fields) and data about the customer that made the order (last three fields) An alternative would be to store the customer information in a separate table named customer and store only the customer_id value in the orders table However, storing customer data... button for an order, you are sent to a page where you can view and update order information, as shown in Figure 9 -6 Figure 9 -6 Administering order details 315 64 8XCH09.qxd 3 16 11/17/ 06 3:39 PM Page 3 16 CHAPTER 9 ■ DEALING WITH CUSTOMER ORDERS Setting Up the Orders Administration Page Before you start creating the admin_orders and the admin_order_details componentized templates, let’s modify admin .php. .. admin .php to load these componentized templates and also modify admin_menu.tpl to display an ORDERS ADMIN link Exercise: Setting Up ADMIN ORDERS 1 Modify admin .php to include a reference to include/app_top .php that we’ll later create: // Load Business Tier require_once BUSINESS_DIR 'catalog .php' ; require_once BUSINESS_DIR 'shopping_cart .php' ; require_once BUSINESS_DIR 'orders .php' ; 2 In the admin .php. .. orderTotalAmount + cartItem.subtotal; END LOOP; Save the order's total amount UPDATE orders SET total_amount = orderTotalAmount WHERE order_id = outOrderId; Clear the shopping cart PERFORM shopping_cart_empty(inCartId); Return the Order ID RETURN outOrderId; END; $$; This function gets called when the customer decides to buy the products in the shopping cart and clicks the Place Order button The... the data tier functions one at a time, and we’ll comment a little upon each one of them Exercise: Implementing the Functions 1 Load pgAdmin III, and connect to the hatshop database 2 Click Tools ➤ Query tool (or click the SQL button on the toolbar) A new query window should appear 3 Use the query tool to execute this code, which creates the order_short_details type and orders_get_most_recent_orders function... PDO-specific functionality $result = DatabaseHandler::Prepare( $sql) ; 319 64 8XCH09.qxd 320 11/17/ 06 3:39 PM Page 320 CHAPTER 9 ■ DEALING WITH CUSTOMER ORDERS // Execute the query and return the results return DatabaseHandler::GetAll($result, $params); } // Gets orders by status public static function GetOrdersByStatus($status) { // Build the SQL query $sql = 'SELECT * FROM orders_get_orders_by_status(:status);';... return data is used to fill the grid at the bottom of the form • orders_update_order is called when the administrator updates an order in edit mode Now implement each of these functions by following the steps from the next exercise Exercise: Implementing the Functions 1 Load pgAdmin III, and connect to the hatshop database 2 Click Tools ➤ Query tool (or click the SQL button on the toolbar) A new query... query tool to execute this code, which creates the orders_get_order_info function in your hatshop database: Create orders_get_order_info function CREATE FUNCTION orders_get_order_info(INTEGER) RETURNS orders LANGUAGE plpgsql AS $$ DECLARE inOrderId ALIAS FOR $1; outOrdersRow orders; BEGIN 325 64 8XCH09.qxd 3 26 11/17/ 06 3:39 PM Page 3 26 CHAPTER 9 ■ DEALING WITH CUSTOMER ORDERS SELECT INTO outOrdersRow... will be stored, you need two data tables: orders and order_detail The orders table stores information regarding the order as a whole, while order_detail contains the products that belong to each order 305 64 8XCH09.qxd 3 06 11/17/ 06 3:39 PM Page 3 06 CHAPTER 9 ■ DEALING WITH CUSTOMER ORDERS ■ So far we have been consistent about naming our tables in singular form (shopping_cart, Tip department, and so on) . what to do with that Place Order button, the next major concerns are what order information to store in the database and how to store it. As you saw in previous chapters, deciding how to store. Adding the orders and the order_detail Tables to the Database 1. Load pgAdmin III, and connect to the hatshop database. 2. Click Tools ➤ Query tool (or click the SQL button on the toolbar).A new. fields). An alternative would be to store the customer information in a separate table named customer and store only the customer_id value in the orders table. However, storing customer data is not one