Shopping Cart is very important part of any online store, it not only allows user to accumulate list of items for final purchase, but also calculates total amount of all the products. Since my last article on PayPal Express Checkout with PHP, I have received few emails asking how to create a simple PHP session based shopping cart for the website. So, keeping that in mind, today we are going to create a shopping cart, which is simple and can be integrated easily in any website that runs on PHP.
I have created 4 files for our shopping cart:
- Config.php (MySql credentials)
- Index.php (list of product information from database)
- Cart_update.php (Updates cart items and redirects back to products list page)
- View_cart.php (Product summery view before the payment)
All our products information should be stored in MySql table, for that we can create a table named “products” using MySql statement below, you can insert the products details manually using PhpMyAdmin, OR use MySql file in downloadable zip, which you can import in PhpMyAdmin.
Once you have database table, you can create a list of products, similar to picture below:
Purpose of the config file is to store various information we need for our script. Here we are just going to enter MySql authentication details to access database table. Just enter the MySql details in the configuration file.
Product List (Index.php)
This will be the page where you want to display the list the products you want to sell. If you have lots of products, it is better to group them in pages using some sort of pagination. And on the right side of the page will be our shopping-cart box, which will keep track of items user going to purchase later.
Since we are working with sessions, we must activate PHP session in our script by including session_start() on top of the code, then we can start writing other codes or include file:
Listing Products from Database
We will basically fetch the records from database and display them on the page. We will also create a HTML form with Add to Cart button. Important part here is the HTML form, notice the hidden input values? Each item contains a form with these hidden values, product code and the return URL, which we will send to cart_update.php using POST method.
Shopping Cart Box
On the right side of the page we will display small shopping cart box to keep track of user items. The main task of the shopping-cart is to look for session variable called $_SESSION[“cart_products”], which holds the collection of user items in an array, and then retrieve and display its content in the box.
The role of the Cart_update.php is to add and remove items in the shopping cart. When user clicks “Add to Cart” button, the form sends some hidden values such as product code and quantity to Cart_update.php using POST method, which we will use to retrieve product info from the database verifying the existence of the product, and then we create or update $_SESSION[“cart_products”] with new array variables. Removing item works similar way, please go though comment lines below, most of the code is self explanatory.
View Item Summary
Now we have everything ready, its time for final page where user can view their products and proceed to payment. It’s good idea to add taxes, shipping and transaction fees along with total amount in this page for the users to see. You can generate any type of data here for the Payment gateway, most Payment gateway prefer HTML form, so I have create some hidden input fields, you can modify them to suit your needs.
Continue to PHP Shopping Cart to PayPal Payment Gateway.