Magento Checkout PHP – Add Custom Discount Without Using Coupon Code in Observer

checkoutmagento-1.7PHP

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();
        }
        }
    }
 }
}

Best Answer

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 execute every time total is calculated and your custom discount is applied on cart, Discount will be display in order,invoice and also in credit memo.

Related Topic