Question

Here is what I’m attempting to do:

class Account < ActiveRecord::Base
   def name
   end
end

class TypeA < Account
end

class TypeB < Account
end

Where TypeA and TypeB are stored on two distinct tables and Account acts pretty much as an abstract interface (with no table associated). They both have large number of entris and large number of fields so I want to keep them separated. Is there a way to go for this ?

(The exemple above does not work as a table for account is expected btw).

UPDATE

Now, if I use modules (as suggested in the answers), that raises another problem:

Let’s say I have

class Transaction < ActiveRecord::Base
   belongs_to :account, :polymorphic => true
end

where account can be TypeA or TypeB. I get the following misbehavior:

i = TypeA.new(:name => "Test")
t = Transaction.new(:account => i)
t.account.name
>> nil

which is not what I want as account.name should return “Test”. How to get this?

Answer 1

Use module instead. You have shared behavior between those two models that you want to share. That’s a great use-case for modules.

# inside lib/account.rb
module Account
   # ...
   def name
     # code here
   end
   # ...
end

# inside app/models/type_a.rb
class TypeA < ActiveRecord::Base
  include Account
end

# inside app/models/type_b.rb
class TypeB < ActiveRecord::Base
  include Account
end