Add code snippet into a class

Question

I have some function which I use in my cart application:

session_start();

if(!isset($_SESSION['products'], $_SESSION['price'], $_SESSION['product_names'],$_SESSION['product_id'])) {
     $_SESSION['products'] = 0;
     $_SESSION['price'] = 0;
     $_SESSION['product_names'] = array();
     $_SESSION['product_id'] = array();
}
if(isset($_POST['add'])) {
      $_SESSION['product_names'][] = $_POST['product_name']; 
      $_SESSION['products']++;
      $_SESSION['price'] += $_POST['price'];
}
if(isset($_POST['empty'])) {
      session_destroy();
      header('Location:index.php');
}

The question is, how can I add this into a class and call it in my view page?

I mean it will still work as <?php echo $_SESSION['price']?>. How can I make this work?

Answer 1

Try this class you're doing in a wrong way.

session_start();    
class Shopping {


    public function __construct()
    {

    }

    //get cart products
    public function getCartProducts()
    {
        $cart = array();
        if(isset($_SESSION['cart'])) {

            $cart = unserialize($_SESSION['cart']);
        }
        return $cart;
    }

    //add product to cart
    public function addToCart($product_details)
    {
        $cart = $this->getCartProducts();
        $product_id = $product_details['product_id'];
        $is_quantity = $this->addQuantity($product_id); //check if product already exists in session if then increase the quantity
        if(!$is_quantity) {
            $product_details = array(
                                'qty' => $product_details['qty'],
                                'price' => $product_details['price'],
                                'product_name' => $product_details['name'],
                                'product_id' => $product_id
            );
            array_push($cart, $product_details);
            $_SESSION['cart'] = serialize($cart);
        }
    }

    //add quantity if product already exists
    private function addQuantity($product_id)
    {

        $cart = $this->getCartProducts();
        $i = 0;
        foreach ($cart as $product) {
            if($product['product_id'] == $product_id)
            {
                $product['qty'] += 1;
                $cart[$i] = $product;
                $_SESSION['cart'] = serialize($cart);
                return true;
            }
            $i++;
        }
        return false;
    }

    public function clearCart()
    {
        unset($_SESSION['cart']);
    }

    public function removeProduct($product_id)
    {
        $cart = $this->getCartProducts();
        $new_cart = array();
        foreach ($cart as $product) {
            if($product['product_id'] != $product_id)
                array_push($new_cart, $product);
        }
        $_SESSION['cart'] = serialize($new_cart);
    }
}

$shop = new Shopping();
$shop->addToCart(array('product_id'=>1,'name'=>'test 1','price'=>'120.00','qty'=>1));
$shop->addToCart(array('product_id'=>3,'name'=>'test 2','price'=>'120.00','qty'=>1));

Answer 2

This is an example of my approach using session in class. References work pretty well.

   class Cart {
      private $container ;
      public function __construct(&$container){
        if (!isset($container) || !is_array($container))
          $session['cart'] = array() ;
        $this->container = &$container ; 
      }

      public function productExists($id){
        return (isset($this->container[$id])) ;
      }
    }

    $cart = new Cart($_SESSION['cart']) ;

At this point all changes in container can be performed in $_SESSION['cart'] . The rest of session array is not affected, that should be safe.