Magento:创建优惠券代码规则，根据购物车中物品的当前折扣进行不同的折扣

magento中有一个事件，

sales_quote_collect_totals_after 这将在计算总数时触发，您可以做的是在会话中设置一个标志，单击按钮应用折扣，并在上面的事件的观察者方法中，检查它是否设置然后应用折扣。

<global>
 <events>
   <sales_quote_collect_totals_after>
     <observers>
       <class>Custom_Module_Model_Observer</class>
       <method>collectTotals</method>
     </observers>
   </sales_quote_collect_totals_after>
 </events>
</global>

在

Custom
  /Module
    /Model
      /Observer.php

在Observer.php中创建函数

public function collectTotals(Varien_Event_Observer $observer)
{
       $quote=$observer->getEvent()->getQuote();
       $quoteid=$quote->getId();
    //check condition here if need to apply Discount
        if($disocuntApply) $discountAmount =5;
     if($quoteid) {
               if($discountAmount>0) {
           $total=$quote->getBaseSubtotal();
           $quote->setSubtotal(0);
           $quote->setBaseSubtotal(0);
           $quote->setSubtotalWithDiscount(0);
           $quote->setBaseSubtotalWithDiscount(0);
           $quote->setGrandTotal(0);
           $quote->setBaseGrandTotal(0);

           $canAddItems = $quote->isVirtual()? ('billing') : ('shipping'); 
           foreach ($quote->getAllAddresses() as $address) {
                    $address->setSubtotal(0);
                    $address->setBaseSubtotal(0);
                    $address->setGrandTotal(0);
                    $address->setBaseGrandTotal(0);
                    $address->collectTotals();
                    $quote->setSubtotal((float) $quote->getSubtotal() + $address->getSubtotal());
                    $quote->setBaseSubtotal((float) $quote->getBaseSubtotal() + $address->getBaseSubtotal());
                    $quote->setSubtotalWithDiscount(
                        (float) $quote->getSubtotalWithDiscount() + $address->getSubtotalWithDiscount()
                    );
                    $quote->setBaseSubtotalWithDiscount(
                        (float) $quote->getBaseSubtotalWithDiscount() + $address->getBaseSubtotalWithDiscount()
                    );
                    $quote->setGrandTotal((float) $quote->getGrandTotal() + $address->getGrandTotal());
                    $quote->setBaseGrandTotal((float) $quote->getBaseGrandTotal() + $address->getBaseGrandTotal());
           $quote ->save(); 
              $quote->setGrandTotal($quote->getBaseSubtotal()-$discountAmount)
              ->setBaseGrandTotal($quote->getBaseSubtotal()-$discountAmount)
              ->setSubtotalWithDiscount($quote->getBaseSubtotal()-$discountAmount)
              ->setBaseSubtotalWithDiscount($quote->getBaseSubtotal()-$discountAmount)
              ->save(); 

            if($address->getAddressType()==$canAddItems) {
             $address->setSubtotalWithDiscount((float) $address->getSubtotalWithDiscount()-$discountAmount);
             $address->setGrandTotal((float) $address->getGrandTotal()-$discountAmount);
             $address->setBaseSubtotalWithDiscount((float) $address->getBaseSubtotalWithDiscount()-$discountAmount);
             $address->setBaseGrandTotal((float) $address->getBaseGrandTotal()-$discountAmount);
             if($address->getDiscountDescription()){
             $address->setDiscountAmount(-($address->getDiscountAmount()-$discountAmount));
             $address->setDiscountDescription($address->getDiscountDescription().', Amount Waived');
             $address->setBaseDiscountAmount(-($address->getBaseDiscountAmount()-$discountAmount));
             }else {
             $address->setDiscountAmount(-($discountAmount));
             $address->setDiscountDescription('Amount Waived');
             $address->setBaseDiscountAmount(-($discountAmount));
             }
             $address->save();
            }//end: if
           } //end: foreach
           //echo $quote->getGrandTotal();
          foreach($quote->getAllItems() as $item){
                         //We apply discount amount based on the ratio between the GrandTotal and the RowTotal
                         $rat=$item->getPriceInclTax()/$total;
                         $ratdisc=$discountAmount*$rat;
                         $item->setDiscountAmount(($item->getDiscountAmount()+$ratdisc) * $item->getQty());
                         $item->setBaseDiscountAmount(($item->getBaseDiscountAmount()+$ratdisc) * $item->getQty())->save();
                       }

                    }
            }
         }

collectTotals函数将被调用，因此不需要显式地调用它。

查看它是如何工作的。

设置magento会话变量，点击这里。

希望有帮助!