public function getPackProducts()
 {
     return sfPlopShopProductQuery::create()->usesfPlopShopProductPackRelatedByProductIdQuery()->filterByPackId($this->getId())->endUse()->find();
 }
 public static function isValid($id)
 {
     return sfPlopShopProductQuery::create()->getValid()->filterById($id)->findOne() ? true : false;
 }
 /**
  * @see getsfPlopShopCartProducts()
  */
 public function getProducts()
 {
     return sfPlopShopProductQuery::create()->usesfPlopShopCartProductQuery()->filterByCartId($this->getId())->endUse()->find();
 }