Adding website/store filter to category product grid in Magento

It appears the Magento developers didn’t think this one through enitrely as this to me is something that should be there by standard. Not everyone has a multi-website set up and products that span two stores, yet that’s the very reason this kind of thing can be a pain to add on not just here but also in the main catalog view and in other views like reports.

I am detailing this by editing core files, this is not the correct way and should be added via a module or local override, which in this case would be very little extra work,  but in essence the steps you need to take are modifying/overriding

Mage_Adminhtml_Block_Catalog_Category_Tab_Product

First find the function

_addColumnFilterToCollection

Add the following if statement at the top, this is checking for our column which we later add and looking up the website ID’s

 if ($column->getId() == 'website_id') {
            $this->getCollection()->joinField('websites',
                'catalog/product_website',
                'website_id',
                'product_id=entity_id',
                null,
                'left');
            return parent::_addColumnFilterToCollection($column);
        }

At the bottom of the function you need to modify the lines like so, to bring in the website names.

parent::_prepareCollection();
$this->getCollection()->addWebsiteNamesToResult();
return $this;

Next add a new function directly underneath the above, this is a custom column callback for our new column which we add next, which is simply a way of adding more criteria onto our $collection, in this case we add the store filter.

   protected function _websiteFilter($collection, $column)
    {

        if (!$value = $column->getFilter()->getValue()) {
            return $this;
        }

        $store = Mage::app()->getWebsite($value);
        $collection->addStoreFilter($value);

        return $this;
    }

Finally add the website column, with our custom filter callback

  if (!Mage::app()->isSingleStoreMode()) {
                         $this->addColumn('websites',
                                 array(
                                     'header'=> Mage::helper('catalog')->__('Websites'),
                     'width' => '100px',
                     'sortable'  => false,
                     'index'     => 'websites',
                     'type'      => 'options',
                     'options'   => Mage::getModel('core/website')->getCollection()->toOptionHash(),
                                     'filter_condition_callback' => array($this, '_websiteFilter'),
             ));
         }

And you’re done.