/**
* Initialize product collection
*
* @param Mage_Catalog_Model_Resource_Eav_Mysql4_Product_Collection $collection Product collection.
*
* @return Mage_Catalog_Model_Layer
*/
public function prepareProductCollection($collection)
{
$query = $collection->getSearchEngineQuery();
$allowedVisibilities = Mage::getSingleton('catalog/product_visibility')->getVisibleInCatalogIds();
$query->addFilter('terms', array('visibility' => $allowedVisibilities));
$allowedStatuses = Mage::getSingleton('catalog/product_status')->getVisibleStatusIds();
$query->addFilter('terms', array('status' => $allowedStatuses));
if (Mage::helper('cataloginventory')->isShowOutOfStock() == false) {
$query->addFilter('terms', array('in_stock' => 1));
}
$query->setQueryType('category_products_layer');
return parent::prepareProductCollection($collection);
}
