The project I'm currently working on (ISH 7.9) requires that the customers are able to order products that have the status 'out of stock'.
Since it feels like a hassle to modify the Basket and Checkout pipelines to achieve something that sounds so trivial I was wondering if there is a setting in the backoffice that enables the customer to order out of stock products?
In the backoffice the closest thing I found is the 'Shopping Cart & Checkout' menu under <MyChannel> -> Applications -> Shopping Cart & Checkout. But there are no options to enable the possibility to order of out of stock products.
Am I missing something, or is there no other choice than to modify the Basket and Checkout pipelines?
There is no setting to enable the purchase of an out of stock product. However, you might want to look into creating an inventory service that will always return 1 or -1 (undefined inventory) as the stock level of any given product.
The code that handles the "add to basket" logic has been moved from the pipelines to the java layer and configured through extension points. See this article about the standard handlers & validators chain that is called when you update the basket.
The ProductInventoryHandler calls the inventory service. You can also try replacing the ProductInventoryHandler with an implementation that ignores the stock settings. Do this by creating an extension with the same name to override the standard one.