No longer able to apply negative tax (for a discount) [#1251142]

I recently updated to the latest dev version (8/16/11) and my custom taxes that were configured to be discounts are no longer working.

In the previous versions i could set a negative tax rate. e.g. -0.2 for %20 discount. Now it just adds 20% regardless of the (-) preceding the amount.

I hadn't updated commerce for a couple weeks so I can't be sure when exactly this problem started, but my guess is that this problem was introduced with the tax rounding features.

Comments

Comment #1

rszrama CreditAttribution: rszrama commented 17 August 2011 at 09:37

Status:

Active

» Fixed

Ahh, you're right. In the event that there was no decimal in a tax amount to round off (or in your case a discount amount, such as an even $10 off), I was returning the amount after running abs() on it without resetting the negative sign like I do at the end of the function. The fix was easy, but on a side note you probably don't need to do this any more. As of a couple releases ago, you can now select a price component type in a product pricing rule so you can specify in a "Multiply the unit price by some amount" action the "Discount" price component type and have the adjustment show up as such in the order total display.

Commit: http://drupalcode.org/project/commerce.git/commitdiff/3e4849a

Comment #2

bradhawkins CreditAttribution: bradhawkins commented 17 August 2011 at 15:19

Thanks Ryan, that solves it!

I did try both as a "Tax Rate" and as a "Discount" when I was initially setting things up, however I settled on tax rate for a couple of reasons:

• as a tax rate I can give it a name that shows up in the subtotal. e.g. "3 or more" discount for buying more than 3 items and "5 or more" for buying 5, etc. Using "Discount" always shows up as "Discount" regardless and might be confusing for the customer (since we'll have a tiered pricing system).

• as a tax rate it can adjust the product prices dynamically before checkout. So if someone adds 3 items to their cart they see the discount applied to all items in the store, if they have 5 it increases the discount further hopefully inciting them to add more items to their cart. : )

I'm going off memory here, so maybe things have changed since I did my initial setup. Regardless you're right that it could work as a "Discount", but I just wanted to give you an idea of why someone might still want to use negative tax rate instead.

Thanks again for the commit!

Comment #3

rszrama CreditAttribution: rszrama commented 17 August 2011 at 15:22

Yeah, your recourse would be to define a new price component type in a module (there is no UI right now) with the name you want. You could then select it from the action. I did fix a longstanding bug for RC1 that solves your second issue; price calculation will always point to the shopping cart order if available, so you should be able to show the discount in advance on product pages.