Helpful debugging script for troubleshooting Magento overrides of controllers

Magento_debug_controller_overrides.md

Overview

For helpful resources on overriding Magento controllers, blocks, models, helpers, etc. see Josh Pratt's post on Magento: Overriding Core Files (Blocks, Models, Resources, Controllers)

Here's a list of search results that I've found most helpful; otherwise good luck with the Googling!

Overriding Controllers

Overriding Magento Core Admin controllers

<!-- in your app/code/local/etc/config.xml file -->
<config>
    <admin>
        <routers>
            <adminhtml>
                <args>
                    <modules>
                        <My_Module before="Mage_Adminhtml">My_Module</My_Module>
                    </modules>
                </args>
            </adminhtml>
        </routers>
    </admin>
</config>

And don't forget to include_once or require_once the parent controller!

<?php

// explicitly require parent controller b/c controllers are not autoloaded
require_once(Mage::getModuleDir('controllers','Mage_Adminhtml') .DS. 'Catalot' .DS. 'Product' .DS. 'AttributeController.php');

class My_Module_Adminhtml_Catalog_Product_AttributeController extends Mage_Adminhtml_Catalog_Product_AttributeController
{
...
}

Overriding Community module's Admin controllers

In this example, the community module will be the Xtento_GridActions module and specifically the Xtento_GridActions_Adminhtml controllers.

<!-- in your app/code/local/etc/config.xml file -->
<config>
    <admin>
        <routers>
            <adminhtml>
                <args>
                    <modules>
                        <My_Module before="Xtento_GridActions_Adminhtml">My_Module_Adminhtml</My_Module>
                    </modules>
                </args>
            </adminhtml>
        </routers>
    </admin>
</config>

And don't forget to include_once or require_once the parent controller!

<?php

// explicitly require parent controller b/c controllers are not autoloaded
require_once(Mage::getModuleDir('controllers','Xtento_GridActions') .DS. 'Adminhtml' .DS. 'Gridactions' .DS. 'PrintController.php');
class My_Module_Adminhtml_Gridactions_PrintController extends Xtento_GridActions_Adminhtml_GridActions_PrintController
{
...
}

Debugging Controller Rewrites

See this awesome Stack Overflow response from benmarks

test.php

<?php
# test.php => (http://mysite.dev/test.php)


ini_set('display_errors',1);
error_reporting(E_ALL^E_STRICT);
include 'app/Mage.php';
Mage::setIsDeveloperMode(true);
Mage::app();


// ===================================================================================================
// FIRST TEST - check if your module is loading correctly
// ===================================================================================================

// replace `COMMUNITY_MODULE` with the module you are looking to override
require_once Mage::getModuleDir('controllers','COMMUNITY_MODULE') . DS . 'path/to/CONTROLLER_NAME.php';

// replace `MY_MODULE` with the module you are looking to override
require_once Mage::getModuleDir('controllers','MY_MODULE') . DS . 'path/to/CONTROLLER_NAME.php';

$controller = new MY_MODULE_CONTROLLER_NAME(
    Mage::app()->getRequest(),    // required constructor arg
    Mage::app()->getResponse()    // required constructor arg
);

echo get_class($controller);

// ===================================================================================================
// END FIRST TEST - check if your module is loading correctly
//
// Visit yoursite.com/test.php and you should see your controller class name. 
// If you see an error, or you see nothing, something fairly low-level is broken. 
// If the error message is unintuitive, check that your module config is being 
// merged and move from there.
// 
// If the class instantiates, we know the following:
// 
// + Base module config is good
// + File structure is appropriate for the config
// + The explicit include is good
// ===================================================================================================


// ===================================================================================================
// SECOND TEST - sniff for controller rewrites
// ===================================================================================================


// you can change 'standard' to 'admin' if you're debugging adminhtml controller rewrites
$router = Mage::app()->getFrontController()->getRouter('standard');
/* @var $router Mage_Core_Controller_Varien_Router_Standard */

$reflection = new ReflectionClass($router);
$modules = $reflection->getProperty('_modules');
$modules->setAccessible(true);

echo "<pre>";
print_r($modules->getValue($router));
echo "</pre>";

// ===================================================================================================
// END SECOND TEST - sniff for controller rewrites
// ===================================================================================================

The second test should output something similar to the below example:

Array
(
    [manage] => Array
        (
            [0] => Mage_Index_Adminhtml
            [1] => Mage_Paygate_Adminhtml
            [2] => Mage_Paypal_Adminhtml
            [3] => Mage_Widget_Adminhtml
            [4] => Mage_Oauth_Adminhtml
            [5] => Mage_Authorizenet_Adminhtml
            [6] => Mage_Bundle_Adminhtml
            [7] => Mage_Centinel_Adminhtml
            [8] => Mage_Compiler_Adminhtml
            [9] => Mage_Connect_Adminhtml
            [10] => Mage_Downloadable_Adminhtml
            [11] => Mage_ImportExport_Adminhtml
            [12] => Mage_Api2_Adminhtml
            [13] => Mage_PageCache_Adminhtml
            [14] => Mage_XmlConnect_Adminhtml
            [15] => Ash_Slideshow_Adminhtml
            [16] => Ash_Up_Adminhtml
            [17] => Bubble_Launcher_Adminhtml
            [18] => EM_Megamenupro_Adminhtml
            [19] => Ebizmarts_AbandonedCart_Adminhtml
            [20] => Ebizmarts_MageMonkey_Adminhtml
            [21] => Ebizmarts_Mandrill_Adminhtml
            [22] => Fishpig_Wordpress_Adminhtml
            [23] => Fooman_Common_Adminhtml
            [24] => Fooman_PdfCustomiser_Adminhtml
            [25] => Infomodus_Upslabel_Adminhtml
            [26] => Webtex_Giftcards_Adminhtml
            [27] => Pan_Authorizenetcim
            [28] => Pan_Gridactions_Adminhtml
            [29] => Xtento_GridActions_Adminhtml
            [30] => Xtento_OrderExport_Adminhtml
            [31] => Mage_Adminhtml
            [32] => Phoenix_Moneybookers
            [33] => Mage_Captcha_Adminhtml
            [34] => Mage_CurrencySymbol_Adminhtml
        )

    ... MORE MODULES (excluded for brevity) ...

    [upslabel] => Array
        (
            [0] => Pan_Infomodusupslabel
            [1] => Infomodus_Upslabel
        )

    [giftcards] => Array
        (
            [0] => Pan_Giftcards
            [1] => Webtex_Giftcards
        )

    [orderedit] => Array
        (
            [0] => Pan_OrderEdit
            [1] => TinyBrick_OrderEdit
        )


    [gridactions] => Array
        (
            [0] => Pan_Gridactions
            [1] => Xtento_GridActions
        )
)

Wherever you see more than one subarray, there is a controller directory rewrite.

benmarks