Magento - 如何在观察者中不使用优惠券代码添加自定义折扣

Question

How can I set discount (not using coupon code) in observer that should be applied on cart, order review(checkout/onepage), Invoice & Memo, this solution only worth of applying discount to cart http://www.magentocommerce.com/boards/viewthread/269154/

And solution like http://magento.ikantam.com/qa/how-add-discount-total-magento cannot work for applying discount from observer

Update :

Adding Answer from link here

config.xml

<?xml version="1.0"?>
<config>
    <modules>
        <Namespace_Modulename>
            <version>1.0.10</version>
        </Namespace_Modulename>
    </modules>
       <global>
      <events>
            <sales_quote_collect_totals_after>
              <observers>
                  <namespace>
                    <type>singleton</type>
                    <class>Namespace_Modulename_Model_Observer</class>
                    <method>setDiscount</method>
                  </namespace>
              </observers>
           </sales_quote_collect_totals_after>             
      </events>
  </global>

Observer.php

class Namespace_Modulename_Model_Observer
{
   public function setDiscount($observer)
   {
     $quote         =  $observer->getEvent()->getQuote();
     $quoteid       =  $quote->getId();
     $discountAmount=  10;

     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().', Custom Discount');
                $address->setBaseDiscountAmount(-($address->getBaseDiscountAmount()-$discountAmount));
                }else {
                    $address->setDiscountAmount(-($discountAmount));
                    $address->setDiscountDescription('Custom Discount');
                    $address->setBaseDiscountAmount(-($discountAmount));
                }
                $address->save();
           }//end: if
        } //end: foreach

        foreach($quote->getAllItems() as $item){
             $rat=$item->getPriceInclTax()/$total;
             $ratdisc=$discountAmount*$rat;
             $item->setDiscountAmount(($item->getDiscountAmount()+$ratdisc) * $item->getQty());
             $item->setBaseDiscountAmount(($item->getBaseDiscountAmount()+$ratdisc) * $item->getQty())->save();
        }
        }
    }
 }
}

Answer 1

Hi may be worth try with this url http://pradeepkumarrcs.blogspot.in/2011/12/applying-custom-discount-amount-in.html

I've used this code explain in blog, it uses sales_quote_collect_totals_after so it would fire every time total is calculated and you custom discount is applied on cart, Discount will be display in order and invoice and also in credit memo.