Event for cart update

Question

I need to create a dynamic shopping cart rule depending on the count of items in the cart.

So I need to listen to an event which changes the item count in the cart (add product, remove product, change quantity).

Does such an event exist or do I have to listen for multiple events?

Answer 1

you can use this observer, it will be triggered whenever the cart is updated.

checkout_cart_save_after

magento_root/app/etc/modules/Namespace_Module.xml

<?xml version="1.0"?>
<config>
    <modules>
        <Namespace_Module>
            <active>true</active>
            <codePool>local</codePool>
        </Namespace_Module>
    </modules>
</config>

magento_root/app/code/local/Namespace/Module/etc/config.xml

<?xml version="1.0"?> 
<config>
    <modules>
        <Namespace_Module>
            <version>0.1</version>
        </Namespace_Module>
    </modules>
    <global>
        <models>
            <namespace_module>
                <class>Namespace_Module_Model</class>
            </namespace_module>
        </models>   
        <events>
            <checkout_cart_save_after>
                <observers>
                    <cart_update>
                        <class>Namespace_Module_Model_UpdateObserver</class>
                        <method>updateCartAfter</method>
                    </cart_update>
                </observers>
            </checkout_cart_save_after>    
        </events>
    </global>
</config>

magento_root/app/code/local/Namespace/Module/Model/UpdateObserver.php

<?php

class Namespace_Module_Model_UpdateObserver {

    public function updateCartAfter($observer) {
        die('product add after');   
    }

}

Answer 2

there are many cart event you can observe its completely depending on your requirement

checkout_cart_add_product_complete
checkout_cart_update_item_complete
checkout_cart_product_add_after
checkout_cart_update_items_before
checkout_cart_update_items_after
checkout_cart_save_before
checkout_cart_save_after
checkout_cart_product_update_after

These are the list to cart events you can use as per your purpose.

Answer 3

In your module config.xml file

<events>
        <checkout_cart_save_after>
            <observers>
                <uniquename>
                    <type>singleton</type>
                    <class>Package_Modulename_Model_Observer</class>
                    <method>removeItem</method>
                </uniquename>
            </observers>
        </checkout_cart_save_after>
    </events>

In your observer File:

public function removeItem($observer)
{

$cart = $observer->getCart();
$total = $cart->getItemsCount();

if($total > 3){
   //your code here
}

Answer 4

There is no specific observer, as they all are different actions, but you can have an action on checkout_cart_save_before. This is executed every time there is a change to the current basket.