Magento AJAX cart quantity update. No items in cart

Question

I am trying to update a Magento "mini-cart" located in the header using a PHP script that is accessed via an AJAX call.

The cart has both "increment" and "decrement" buttons. When clicked, the PHP script is run and the quantity of a specific product in the cart gets saved and updated.

Now, the problem is that when I run this PHP script, there appear to be no items in the shopping cart. I have looked at the Session IDs on both when I am on the main home page, and when the script is run and they both seem to be different. This is why I think the script seems to believe that I don't have any items in the cart.

I believe the code I have written to get the Session ID and the cart items is correct. Does anyone know what I might be doing wrong here?

Code shown below. I know that this could probably be written better, but for now I just want to see something working!.

The HTML in header.phtml (this is within the loop to get all items in basket - works fine here):

<button id="decrement" onclick="updateCart(<?php echo $product->getId(); ?>);" class="decrement">-</button>
<input type="text" class="quantity" name="quantity" id="quantity" value="<?php echo $product->getQty(); ?>">
<button id="increment" onclick="updateCart(<?php echo $product->getId(); ?>);" class="increment">+</button>

The AJAX:

function updateCart(productId, qty) {
            qty = jQuery('#quantity').val()
            jQuery.ajax({
                type: "POST",
                dataType: "HTML",
                data: { productId : productId, qty : qty },
                url: "scripts/get_cart_script.php?productId=" + productId + "&qty=" + qty,
                success: function (data) {
                    alert("Success");

                },
                error: function(data){
                    alert("Failure");
                }
            });
        }

The PHP:

require_once  $_SERVER['DOCUMENT_ROOT'] . '/app/Mage.php';

Mage::app();

// Get session
Mage::getSingleton('core/session', array('name'=>'frontend'));

// Check for a product id
if(isset($_REQUEST['productId']))
{

    // Product ID and Quantity
    $pid = $_REQUEST['productId'];
    $qnt = $_REQUEST['qty'];

    $cart = Mage::getSingleton('checkout/cart');
    $items = $cart->getItems(); 

    foreach ($items as $item) :
        if($pid == $item->getId()) :
            echo $item->getQty();
            $item->setQty($qnt); 
            $cart->save();
        endif;
    endforeach;     
};

Pradeep Sanku Pradeep Sanku · Accepted Answer · 2013-12-19T18:59:12

You are calling the ajax update function with 2 arguments i.e product id and qty.and you called a function on increment and decrment button called update with only one argument called productid.

you can do one thing.change the ajax update function argument.use only one argument called product id.

Magento AJAX cart quantity update. No items in cart

1 Answers