We're in the process of moving to 2.0 and we need a way to allow our customers to add a variably priced donation on checkout - a way for them to "round up" their purchase by adding a donation of a calculated amount or any other amount they chose. In our 1.1 version of the store, we are able to achieve this by having an entirely JSON cart and forcing the customer through the cart page before they reach checkout. As we move to 2.0, I would like to make use of the sidecart and add this "round up" donation functionality to the checkout page. I am currently working with this snippet - https://wiki.foxycart.com/v/2.0/snippets/gift_wrapping_checkbox_on_checkout
- as a starting point, however we need our price value to be variable, so I am struggling to get the hmac verification working. Is there a way I can have an --OPEN-- price and still have it get verified so that the link works?
I'll whisper our development url. If you add any product and proceed to the checkout, you'll see this "Increase your impact" in section 4, but will notice there's an error on the price mismatch because of the verification failure.
Any thoughts? Will it be possible to have this functionality on the Checkout page? Another option might be to have it on the sidecart where I can use php to generate the hashes?
Thanks for your help,