I'm working for a startup and we have a customer who uses Demandware for their online store.
Our company provides vouchers which are worth a specific amount of money. So customers on the retail site can enter the voucher number near the end of the checkout experience and if it's worth, say, 10 dollars, their shopping cart is updated (-10).
I have the CTO saying we just need to "drop a few lines of javascript" onto the retailer online store. But I think this requires a Demandware plugin (especially updating a shopping cart), which involves signing up for a developer or partnership account (which takes some time), learning Demand Script and building the plugin, then releasing it to Saleforce's app store. Am I correct? Is this the only way to achieve this?
Just to be clear, the functionality is: the voucher code box needs to take a voucher number, an API request is made to our service to check what it's worth, then update the cart.