title: Magento : change price in cart on the fly
body: <p><br><br>We have 2 observers to change product price in the cart : <code>checkout_cart_product_add_after</code> to change price the first time the product is added to cart, and <code>checkout_cart_update_items_after</code> to change price for each item in the cart (when user click the "Modify cart" button on cart page). Both are running OK.</p>
  
  <p>My question : On the cart page, when user clicks the link "Edit" to edit the product in product page (so he can change quantity, ...) and clicks the <strong>"Update cart"</strong> button, this update button does not read any observer to refresh price. Only the quantity is refreshed.</p>
  
  <p>How to force this <strong>"Update cart"</strong> (<em>on product page</em>) action to process the code in observer? Is there another observer for this? The code in <code>checkout_cart_product_add_after</code> is executed just the first time the product is added to the cart?</p>
  
  <p>Thanks.</p>