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.
Initializing the Shopping Cart Class
Important: The Cart class utilizes CodeIgniter's Session Class 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 Session Documentation , and set the session preferences in your appliction/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.
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);
Updating The Cart
To update the information in your cart, pass an array containing the product ID and quantity to the $this->cart->update() function:
$data = array(
'id' => '123XYZ',
'qty' => 3
);
$this->cart->update($data);
Just as you can when inserting, you may use a multi-dimensional array in order to update multiple items simultaneously:
$data = array(
array(
'id' => 'sku_123ABC',
'qty' => 3
),
array(
'id' => 'sku_567ZYX',
'qty' => 4
),
array(
'id' => 'sku_965QRS',
'qty' => 2
)
);
$this->cart->update($data);
Deleting an Item From The Cart
To delete an item from your cart, pass an array containing the product ID and a quantity of zero to the $this->cart->update() function:
$data = array(
'id' => '123XYZ',
'qty' => 0
);
$this->cart->update($data);
You may use a multi-dimensional array in order to delete multiple items simultaneously:
$data = array(
array(
'id' => 'sku_123ABC',
'qty' => 0
),
array(
'id' => 'sku_567ZYX',
'qty' => 0
),
array(
'id' => 'sku_965QRS',
'qty' => 0
)
);
$this->cart->update($data);
Displaying the Cart
To display the cart you will create a view file with code similar to the one shown below.
Please note that this example uses the form helper.
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->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.