Can't override a core model in Magento

Question

Hi,

I’m trying to override Mage_Catalog_Model_Layer_Filter_Category. In system.log I’m getting a warning:

Warning: include(Mycomp_Catalog_Model_Layer_Filter_Category.php): failed to open stream: No such file or directory in /var/www/magento/includes/src/Varien_Autoload.php on line 93 Warning: include(): Failed opening ‘Mycomp_Catalog_Model_Layer_Filter_Category.php’ for inclusion (include_path=’/var/www/magento/includes/src:.:/usr/share/php:/usr/share/pear’) in /var/www/magento/includes/src/Varien_Autoload.php on line 93

What am I doing wrong?

Mycomp/Catalog/etc/config.xml:

<?xml version="1.0"?>
<config>
<modules>
    <Mycomp_Catalog>
        <version>0.1.0</version>
    </Mycomp_Catalog>
</modules>
<global>
    <models>
        <catalog>
            <rewrite>                    
                <layer_filter_category>Mycomp_Catalog_Model_Layer_Filter_Category</layer_filter_category>
            </rewrite>
        </catalog>
    </models>
</global>

Mycomp/Catalog/Model/Layer/Filter/Category.php:

class Mycomp_Catalog_Model_Layer_Filter_Category extends  Mage_Catalog_Model_Layer_Filter_Category
{

} 

app/etc/modules/Mycomp_All.xml:

<?xml version="1.0"?>
<config>
  <modules>
     <Mycomp_Catalog>
       <codePool>local</codePool>
       <active>true</active>
     </Mycomp_Catalog>
  </modules>
 </config> 

Answer 1

have you tried to require the file of the clas you're extending?
In Mycomp/Catalog/Model/Layer/Filter/Category.php add before class declaration:

require_once 'Mage/Catalog/Model/Layer/Filter/Category.php';

Answer 2

It doesn't appear here, so did you set up the models for the Mycomp_Catalog module? Amend your global section like this:

<global>
    <models>
        <catalog>
            <rewrite>                    
                <layer_filter_category>Mycomp_Catalog_Model_Layer_Filter_Category</layer_filter_category>
            </rewrite>
        </catalog>
        <mycompcatalog>
            <class>Mycomp_Catalog_Model</class>
        </mycompcatalog>
    </models>
</global>

That's my only guess off the bat. Hope that helps!

Thanks, Joe

Answer 3

These kinds of problems are notriously difficult to debug via a forum. Here's a module with a working override (at least, it works on my install of 1.4 CE) Diff it vs. yours to see what's different, or just try installing in on your install, and if it doesn't work you know there's a problem elsewhere.

http://alanstorm.com/testbed/Mycomp.tar.gz