I am trying to add Magento Promotion Rule Apply extra 5% off coupon with existing offer of buy 2 get 10%. SO after using coupon code total off will be 15% . I have created a coupon code for giving extra 5% off. But after using coupon code i am not getting total of 15% off. The extra 5% is applying on amount which is deducted after 10% off. So basically this extra 5% off is not applying on original price. So can anyone give me the solution.
unfortunately default Magento behavior is to apply amount based at discounted product price. At our module we create new rules with few types of price behavior, but if you need to customize default Magento behavior you can change this file -
app/code/core/Mage/SalesRule/Model/Validator.php (better way is copy this file to local folder to redefine it) and change lines with discount deduct like this -
$discountAmount = ($qty * $itemPrice - $item->getDiscountAmount()) * $_rulePct;
Here you can see, that discount calculated based on item price with deducted discount amount.