/** * Retrieve rule's primary coupon * * @return Mage_SalesRule_Model_Coupon */ public function getPrimaryCoupon() { if ($this->_primaryCoupon === null) { $this->_primaryCoupon = Mage::getModel('salesrule/coupon'); $this->_primaryCoupon->loadPrimaryByRule($this->getId()); $this->_primaryCoupon->setRule($this)->setIsPrimary(true); } return $this->_primaryCoupon; }