Refer to similar associated models with a common name

Question

I have these models:

class Bill < ActiveRecord::Base
  has_many :calls
  has_many :text_messages
end

class Call < ActiveRecord::Base
  belongs_to :bill
end

class TextMessage < ActiveRecord::Base
  belongs_to :bill
end

Now, in my domain calls and text messages are both "the same kind of thing" -- i.e., they're both "bill items". So I'd like some_bill.bill_items to return all calls and text messages associated with that bill. What's the best way to do this?

Answer 1

You could create a new model, BillItems and insert it into your relationship chain. Then you could access all bill items collectively or individual call/text messages via a has many through relationship. Another possibility would be to look into single table inheritance.