Does anyone know of a way to make a product conditional on another product? For example I offer various subscriptions using WC Subscriptions extension. I also have an add-on that is available for only two different subscriptions. The add-on is setup as a simple product because the customer needs the ability to change the quantity. The subscriptions are setup as Variable subs to offer to payment plan options.
My initial thought is to create a custom function on the cart/checkout page that checks if the add-on has been added and if so, check to make sure 1 of the other two associated products are there.
Is there a simpler method?