How to apply all valid Shopping Cart Price Rules to quote?

Question

I am trying to create extension that add coupon code (Ajax) to one page checkout page last step. See http://www.lelandcope.com/2012/04/how-to-create-an-ajax-coupon-discount-code-box-in-magento/

Following code of CartController customcouponPostAction() which applies coupon code. its works fine

        $this->_getQuote()->getShippingAddress()->setCollectShippingRates(true);
        $this->_getQuote()->getShippingAddress()->collectShippingRates();
        $this->_getQuote()->setCouponCode(strlen($couponCode) ? $couponCode : '')
            ->collectTotals()
            ->save();

Shipping and handling charges calculation work fine as per table rate but when another Shopping Cart Price Rule which is free shipping above $15 (See http://www.phpro.be/news/configuring-shopping-cart-price-rules-magento-free-shipping) is also valid then shipping charge not become zero its still same as table rate.

Same scenario works like charm in cart page.

What am I missing?

Answer 1

A coupon code that enables 'Free shipping' does not automatically set the shipping price to zero. It just puts the 'Free shipping' in the shipping methods list for the customer to select.
I bet that if you refresh the checkout page after entering a valid coupon and go through all the steps again, in the shipping method step you should see the 'Free shipping' option available.