Order Total Calculation Order

[RixStix]

I would have bet that the question has been asked & answered but I couldn't find it either with the forum search or google search.

Zencart 1.5.3

My assumption based upon older zencart documents was that order total "Sort order" affected the actual sequence in which calculations are performed. ie: any sort order less than the Sub-Total sort order would be performed and the SubTotal would be based upon the outcome of that calculation.

Instead, the values are being displayed on the invoice in the order specified by "sort order" but the calculations are not performed in that order.

Discount coupon: 80
Quantity discount: 90
Sub-Total: 100
Shipping: 200
Tax: 300
Store Credit: 840
Total: 999
===========================
Actual Customer order/invoice

Quantity Discount:	-$2.57####(USD)
Discount Coupon: 14turkey :	-$21.39####(USD)
Sub-Total:	$343.37####(USD)
Free Shipping Options (Free Shipping):	$0.00####(USD)
Total:	$319.41####(USD)

======================================

Based upon the sort orders, my expectation is that the figures printed should have been:

Quantity Discount:	-$2.57####(USD)
Discount Coupon: 14turkey :	-$21.39####(USD)
Sub-Total:	$319.41####(USD)
Free Shipping Options (Free Shipping):	$0.00####(USD)
Total:	$319.41####(USD)

[lat9]

I believe that your assumption is true regarding the calculation order, with the provision that the quantity-discount and coupon processing should have a sort-order higher than the subtotal since they count on the subtotal to perform their calculations. Additionally, the coupon sort-order should be after the shipping calculation if you have coupons that provide "free shipping".