I have a product that is part of a Groupon-like promotion. The customer purchases a promo code at the Groupon-like website and those coupon codes are entered into my Ubercart system as 100%-off discounts. I want to only allow this particular product to be purchased when one of those specific codes has been entered into the cart. In other words, the credit card entry panel would not appear until they have entered a valid code for that product's promotion.
Is that possible? If so, how might I accomplish that? Rules/Conditional Actions?