/**
*
* @return Mage_Sales_Model_Resource_Order_Shipment_Grid_Collection
*/
public function getCollection()
{
$collection = parent::getCollection();
if ($collection && !$this->getIsI4ShipsJoined()) {
/* @var $collection Mage_Sales_Model_Resource_Order_Shipment_Grid_Collection */
$resource = Mage::getSingleton('core/resource');
/* @var $resource Mage_Core_Model_Resource */
$shipsTableName = $resource->getTableName('zitec_dpd_ships');
$manifestTableName = $resource->getTableName('zitec_dpd_manifest');
$collection->getSelect()->joinLeft(array('ships' => $shipsTableName), 'ships.shipment_id = main_table.entity_id', array('zitec_manifest_id' => 'ships.manifest_id'))->joinLeft(array('manifest' => $manifestTableName), 'manifest.manifest_id = ships.manifest_id', array('zitec_manifest_ref' => 'manifest.manifest_ref'));
$this->setIsI4ShipsJoined(true);
}
return $collection;
}
