add code to core, how?

Question

I want add 2 lines code into but I want do this from my Extension How can I do this job ?

Don't want to add code to core file and then insert it into local folder

Is this possible add directly into my extension ?

I want add 2 lines below into

/code/core/Mage/Checkout/controllers/CartController.php

in the public function estimatePostAction()

under the $region = (string) $this->getRequest()->getParam('region');

Code is :

$cityDiff = $this->getRequest()->getParam('city');
Mage::getSingleton('core/session')->setEstimatedCity($cityDiff);

Answer 1

according to your requirement, if you expect you extension can work on further version I suggest you use Observer to listen Magento event then add data to core/session.

in your config.xml, define event listener. if you know the exactly event you want to listen, or listen all controller post dispatch.

<global>
<events>
    <controller_action_postdispatch>
        <observers>
            <controller_action_after>
                <class>YOUR_MODULE/observer</class>
                <method>listenControllerActionPostDispatch</method>
            </controller_action_after>
        </observers>
    </controller_action_postdispatch>

</events></global>

in your Model/Observer.php

class YOUDMOUDLE_Model_Observer {

public function listenControllerActionPostDispatch($observer)
{
    if($observer->getEvent()
        ->getControllerAction()->getFullActionName() == 'YOUR_TARGET')
    {
        $cityDiff = Mage::app()->getRequest()->getParam('city');
        Mage::getSingleton('core/session')->setEstimatedCity($cityDiff);
    }

}

Answer 2

I'm no expert but think it would be something like this - anyway hopefully gets you on the right track:

Mage_Checkout_CartController_New extends Mage_Checkout_CartController { /** * Initialize shipping information */ public function estimatePostAction() { $country = (string) $this->getRequest()->getParam('country_id'); $postcode = (string) $this->getRequest()->getParam('estimate_postcode'); $city = (string) $this->getRequest()->getParam('estimate_city'); $regionId = (string) $this->getRequest()->getParam('region_id'); $region = (string) $this->getRequest()->getParam('region'); $cityDiff = $this->getRequest()->getParam('city'); Mage::getSingleton('core/session')->setEstimatedCity($cityDiff); $this->_getQuote()->getShippingAddress() ->setCountryId($country) ->setCity($city) ->setPostcode($postcode) ->setRegionId($regionId) ->setRegion($region) ->setCollectShippingRates(true); $this->_getQuote()->save(); $this->_goBack(); } }

Sometimes config XML also needs to be told about the new overriding class? http://www.magentocommerce.com/boards/viewthread/14103/