If the payment terminal supports barcode scanning, it's optional
whether or not you integrate that functionality into the payment module.
The result of a barcode scan is a product search, which can be initiated
with this code:
Alloy.Router.navigateToProductSearch({query:barcode, category_id:Alloy.CFG.root_category_id});
In this example, the barcode variable is the result that was returned
from the device from the scan.