Polymorphic Models in Ruby on Rails?

Question

For a project I'm working on, the store has two types of products - a real product and a group of products.

For this discussion, let's call them "1 T shirt" and "a box of T shirts". For one t-shirt, I need to store the normal attributes - price, sku, size, color, description, etc. For the box of t-shirts I need to have a price, sku, description, and a list of t-shirts that are included.

So right now, I'm representing this with the Shirt and ShirtCollection models. I can see this causing difficulty down the road when I need to do reporting and order management and making sure SKUs are unique.

So what's the best way of representing this?

Answer 1

I would have the following models

Tshirt
TshirtBox has_many TshirtItems
TshirtBoxItems (This is basically a join table with an id tshirt_box_id and tshirt_id) belongs_to TshirtBox

TshirtBoxItems is a way to link a Tshirt with a box and potentially other things in the future.

Answer 2

You can have a Tshirt table and then self reference it with a has_many :through association.

Tshirt - id, sku, price, size, color, description, is_box

TshirtBox - parent_tshirt (id that references tshirt), child_tshirt (id that references tshirt)

Check out this link for more on self referential has_many :through http://www.aldenta.com/2006/11/10/has_many-through-self-referential-example/