checkout Helper Url overload not working

Question

I have a simple need to change all the cart URLs to force it to a store's cart. I have set it up the same way as all the examples out there, but it's not the data, it the URL I'm trying to get to. Here is what I have.

The config.xml

<helpers>
  <centralprocessing>
    <class>Wsu_Centralprocessing_Helper</class>
  </centralprocessing>
  <checkout>
    <rewrite>
        <url>Wsu_Centralprocessing_Helper_Url</url>
    </rewrite>
  </checkout>
</helpers>

And the helper file, app\code\local\Wsu\Centralprocessing\Helper\Url.php

class Wsu_Centralprocessing_Helper_Url extends Mage_Checkout_Helper_Url{
    /**
     * Retrieve shopping cart url
     *
     * @return string
     */
    public function getCartUrl(){
        $storeId = 1;//pick up from setting.. look to later but hard code now
        return Mage::app()->getStore($storeId)->getUrl('checkout/cart');
        return $this->_getUrl('checkout/cart');//old function
    }

    /**
     * Retrieve checkout url
     *
     * @return string
     */
    public function getCheckoutUrl(){
        $storeId = 1;//pick up from setting.. look to later but hard code now
        return Mage::app()->getStore($storeId)->getUrl('checkout/onepage');
        return $this->_getUrl('checkout/onepage');//old function
    }
}

As far as I see it, this should be working but it's not. Any ideas why? Thank you

UPDATE As suggested in the post, if the class is being invoked directly i.e. new Mage_Checkout_Helper_Url or if another class is extending it is may fail. So with that in mind a quick test of the only other spot that has the method getCartUrl() which is what I need to get at. The helper file Cart.php (app\code\core\Mage\Checkout\Helper\Cart.php) does have that function in it. It extends Mage_Core_Helper_Url. So I added the helper file in my module app\code\local\Wsu\Centralprocessing\Helper\Cart.php with

class Wsu_Centralprocessing_Helper_Cart extends Mage_Checkout_Helper_Cart{
    /**
     * Retrieve shopping cart url
     *
     * @return string
     */
    public function getCartUrl(){
        $storeId = 1;//pick up from setting.. look to latter but hard code now
        return Mage::app()->getStore($storeId)->getUrl('checkout/cart');
        return $this->_getUrl('checkout/cart');
    }

}

and adjusted the config to match

<helpers>
  <centralprocessing>
    <class>Wsu_Centralprocessing_Helper</class>
  </centralprocessing>
  <checkout>
    <rewrite>
        <url>Wsu_Centralprocessing_Helper_Url</url>
        <cart>Wsu_Centralprocessing_Helper_Cart</cart>
    </rewrite>
  </checkout>
</helpers>

This didn't help, so that doesn't seem to be the path I need I believe.

Answer 1

I'm on my phone so I can't search for you, but you need to determine if the class is being invoked directly i.e. new Mage_Checkout_Helper_Url or if another class is extending it. That's the only way this rewrite won't work.

Answer 2

Based on OP update:

For the assertion that your rewrite is or is not working, you need to ensure that you are instantiating the correct class. The following test should suffice:

ini_set('display_errors',true);
error_reporting(E_ALL | E_STRICT);
require 'app/Mage.php';
Mage::setIsDeveloperMode(true);
umask(0);
Mage::app();

echo get_class(
    Mage::helper('checkout/url')
);

Output will be one of the following:

• Wsu_Centralprocessing_Helper_Cart
• Mage_Checkout_Helper_Url
• blank / error message

It looks like what you actually need to rewrite is the block class which is rendering the link so that you may pas in the correct store scope. However, I question the need for such a rewrite, as you should be able to pass in store params to the Mage_Core_Model_Url class.