magento 1.9 correct way to extend Mage_Adminhtml_Catalog_ProductController

Question

y'all. What is the best way to achieve this epic feat of intellectual prowess?

Is this a good start?

require_once("mage/Adminhtml/controllers/Catalog/ProductController");
class Company_adminhtml_Catalog_ProductController extends Mage_AdminhtmlCatalog_ProductController{
    ....
}

From that point, what else must be achieved?

Answer 1

In your controller

require_once 'Mage/Adminhtml/controllers/Catalog/ProductController.php';   
class Company_Adminhtml_Catalog_ProductController extends Mage_Adminhtml_Catalog_ProductController {

}

In your config.xml

<config>
    ....
    <admin>
          <routers>
            <adminhtml>
                <args>
                    <modules>
                        <Company_Adminhtml before="Mage_Adminhtml">Company_Adminhtml</Company_Adminhtml>
                    </modules>
                </args>
            </adminhtml>
          </routers>
      </admin>
</config>

See Magento: Overriding Core Files (Blocks, Models, Resources, Controllers)

Answer 2

Magento won't find the controller as it would search for Mage/Customer/AccountController.php. I guess the only way is in fact require_once a controller php class file.

I think here you can find a complete solution for this.

The other, much less elegant way is to copy the whole controller you want to extend, and let it extend Mage_Core_Controller_Front_Action.

Edit: Or Mage_Adminhtml_Controller_Action for admin area controller.