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diff --git a/user_guide_src/source/libraries/cart.rst b/user_guide_src/source/libraries/cart.rst new file mode 100644 index 000000000..2384e92b9 --- /dev/null +++ b/user_guide_src/source/libraries/cart.rst @@ -0,0 +1,294 @@ +################### +Shopping Cart Class +################### + +The Cart Class permits items to be added to a session that stays active +while a user is browsing your site. These items can be retrieved and +displayed in a standard "shopping cart" format, allowing the user to +update the quantity or remove items from the cart. + +Please note that the Cart Class ONLY provides the core "cart" +functionality. It does not provide shipping, credit card authorization, +or other processing components. + +.. contents:: Page Contents + +Initializing the Shopping Cart Class +==================================== + +.. important:: The Cart class utilizes CodeIgniter's :doc:`Session + Class <sessions>` to save the cart information to a database, so + before using the Cart class you must set up a database table as + indicated in the :doc:`Session Documentation <sessions>`, and set the + session preferences in your application/config/config.php file to + utilize a database. + +To initialize the Shopping Cart Class in your controller constructor, +use the $this->load->library function:: + + $this->load->library('cart'); + +Once loaded, the Cart object will be available using:: + + $this->cart + +.. note:: The Cart Class will load and initialize the Session Class + automatically, so unless you are using sessions elsewhere in your + application, you do not need to load the Session class. + +Adding an Item to The Cart +========================== + +To add an item to the shopping cart, simply pass an array with the +product information to the $this->cart->insert() function, as shown +below:: + + $data = array( + 'id' => 'sku_123ABC', + 'qty' => 1, + 'price' => 39.95, + 'name' => 'T-Shirt', + 'options' => array('Size' => 'L', 'Color' => 'Red') + ); + + $this->cart->insert($data); + +.. important:: The first four array indexes above (id, qty, price, and + name) are **required**. If you omit any of them the data will not be + saved to the cart. The fifth index (options) is optional. It is intended + to be used in cases where your product has options associated with it. + Use an array for options, as shown above. + +The five reserved indexes are: + +- **id** - Each product in your store must have a unique identifier. + Typically this will be an "sku" or other such identifier. +- **qty** - The quantity being purchased. +- **price** - The price of the item. +- **name** - The name of the item. +- **options** - Any additional attributes that are needed to identify + the product. These must be passed via an array. + +In addition to the five indexes above, there are two reserved words: +rowid and subtotal. These are used internally by the Cart class, so +please do NOT use those words as index names when inserting data into +the cart. + +Your array may contain additional data. Anything you include in your +array will be stored in the session. However, it is best to standardize +your data among all your products in order to make displaying the +information in a table easier. + +The insert() method will return the $rowid if you successfully insert a +single item. + +Adding Multiple Items to The Cart +================================= + +By using a multi-dimensional array, as shown below, it is possible to +add multiple products to the cart in one action. This is useful in cases +where you wish to allow people to select from among several items on the +same page. + +:: + + $data = array( + array( + 'id' => 'sku_123ABC', + 'qty' => 1, + 'price' => 39.95, + 'name' => 'T-Shirt', + 'options' => array('Size' => 'L', 'Color' => 'Red') + ), + array( + 'id' => 'sku_567ZYX', + 'qty' => 1, + 'price' => 9.95, + 'name' => 'Coffee Mug' + ), + array( + 'id' => 'sku_965QRS', + 'qty' => 1, + 'price' => 29.95, + 'name' => 'Shot Glass' + ) + ); + + $this->cart->insert($data); + +Displaying the Cart +=================== + +To display the cart you will create a :doc:`view +file </general/views>` with code similar to the one shown below. + +Please note that this example uses the :doc:`form +helper </helpers/form_helper>`. + +:: + + <?php echo form_open('path/to/controller/update/function'); ?> + + <table cellpadding="6" cellspacing="1" style="width:100%" border="0"> + + <tr> + <th>QTY</th> + <th>Item Description</th> + <th style="text-align:right">Item Price</th> + <th style="text-align:right">Sub-Total</th> + </tr> + + <?php $i = 1; ?> + + <?php foreach ($this->cart->contents() as $items): ?> + + <?php echo form_hidden($i.'[rowid]', $items['rowid']); ?> + + <tr> + <td><?php echo form_input(array('name' => $i.'[qty]', 'value' => $items['qty'], 'maxlength' => '3', 'size' => '5')); ?></td> + <td> + <?php echo $items['name']; ?> + + <?php if ($this->cart->has_options($items['rowid']) == TRUE): ?> + + <p> + <?php foreach ($this->cart->product_options($items['rowid']) as $option_name => $option_value): ?> + + <strong><?php echo $option_name; ?>:</strong> <?php echo $option_value; ?><br /> + + <?php endforeach; ?> + </p> + + <?php endif; ?> + + </td> + <td style="text-align:right"><?php echo $this->cart->format_number($items['price']); ?></td> + <td style="text-align:right">$<?php echo $this->cart->format_number($items['subtotal']); ?></td> + </tr> + + <?php $i++; ?> + + <?php endforeach; ?> + + <tr> + <td colspan="2"> </td> + <td class="right"><strong>Total</strong></td> + <td class="right">$<?php echo $this->cart->format_number($this->cart->total()); ?></td> + </tr> + + </table> + + <p><?php echo form_submit('', 'Update your Cart'); ?></p> + +Updating The Cart +================= + +To update the information in your cart, you must pass an array +containing the Row ID and quantity to the $this->cart->update() +function: + +.. note:: If the quantity is set to zero, the item will be removed from + the cart. + +:: + + $data = array( + 'rowid' => 'b99ccdf16028f015540f341130b6d8ec', + 'qty' => 3 + ); + + $this->cart->update($data); + + // Or a multi-dimensional array + + $data = array( + array( + 'rowid' => 'b99ccdf16028f015540f341130b6d8ec', + 'qty' => 3 + ), + array( + 'rowid' => 'xw82g9q3r495893iajdh473990rikw23', + 'qty' => 4 + ), + array( + 'rowid' => 'fh4kdkkkaoe30njgoe92rkdkkobec333', + 'qty' => 2 + ) + ); + + $this->cart->update($data); + +What is a Row ID? +***************** + +The row ID is a unique identifier that is +generated by the cart code when an item is added to the cart. The reason +a unique ID is created is so that identical products with different +options can be managed by the cart. + +For example, let's say someone buys two identical t-shirts (same product +ID), but in different sizes. The product ID (and other attributes) will +be identical for both sizes because it's the same shirt. The only +difference will be the size. The cart must therefore have a means of +identifying this difference so that the two sizes of shirts can be +managed independently. It does so by creating a unique "row ID" based on +the product ID and any options associated with it. + +In nearly all cases, updating the cart will be something the user does +via the "view cart" page, so as a developer, it is unlikely that you +will ever have to concern yourself with the "row ID", other then making +sure your "view cart" page contains this information in a hidden form +field, and making sure it gets passed to the update function when the +update form is submitted. Please examine the construction of the "view +cart" page above for more information. + + +Function Reference +================== + +$this->cart->insert(); +********************** + +Permits you to add items to the shopping cart, as outlined above. + +$this->cart->update(); +********************** + +Permits you to update items in the shopping cart, as outlined above. + +$this->cart->total(); +********************* + +Displays the total amount in the cart. + +$this->cart->total_items(); +**************************** + +Displays the total number of items in the cart. + +$this->cart->contents(); +************************ + +Returns an array containing everything in the cart. + +$this->cart->has_options(rowid); +********************************* + +Returns TRUE (boolean) if a particular row in the cart contains options. +This function is designed to be used in a loop with +$this->cart->contents(), since you must pass the rowid to this function, +as shown in the Displaying the Cart example above. + +$this->cart->product_options(rowid); +************************************* + +Returns an array of options for a particular product. This function is +designed to be used in a loop with $this->cart->contents(), since you +must pass the rowid to this function, as shown in the Displaying the +Cart example above. + +$this->cart->destroy(); +*********************** + +Permits you to destroy the cart. This function will likely be called +when you are finished processing the customer's order. |