Question

I’ve got a Product model, a Statuses model and a Productstatuses model.

Product has_many :productstatuses, :dependent => :destroy
Product has_many :statuses, :through => :productstatuses

Status has_many :productstatuses
Status has_many :products, :through => :productstatuses

Productstatus belongs_to :product
Productstatus belongs_to :status

I’m using the statuses in two ways.

One, to show progression as a product is making its way through our system (statuses bookmark, processing, approved. Once a product has a status of approved, it can’t move backward in the system (so that I don’t create a public 404). A product must have one of these three at all times to be valid.

I also use the statuses for different “flags” on the products:

• retired when a product is no longer available (this product will also always have approved status; approved == publically indexable in our sitemap, but retired removes it from everywhere on our site (index, archives, etc) without 404’ing its permalink)
• pre-sale when a product is not available yet (could have any of the three above)
• needs-images (could have any of the three)

My question is a bit of a two-parter:

1. Should I have just made the “flags” statuses booleans on the Product model? I ask because:

2. How do I write a scope that says approved but not retired? Or approved but not retired and not needs-images?

With a boolean, I can just have a scope like
scope :not_foo where(:foo = false) and chain those all up. I’m drawing a blank on the best way to do the same with the above setup. I thought the has_many :through setup was the way to go (the flags as booleans just seemed like a lot of excess falses in my database) but database structure/planning is not my strong suit.

Answer 1

I would suggest using state machine for the product flow pre-sale, approved and retired and a boolean flag for needs-images for indicating additional state which is out of the flow.