Polymorphic or has_many :through for recording cash flow

Question

So far I've spent a day trying to model the following, which I believe should be simple, I've looked at it too much, and there is probably an obvious solution staring at me..

Objective: Users book clients onto events which can be chargeable, users access cashbox area to account for payments for those chargeable events(money in), other_charges(money in)but only related to clients) and record general expenses(money out)unrelated to events or clients).

So far: User, Client and Event model created with correct associations. Typical scenario; user books client onto event, that can be chargeable (boolean).

# == Associations so far

class User < ActiveRecord::Base
  has_many :clients
  has_many :events
end

class Client < ActiveRecord::Base
  has_one :user, through: :events
  has_many :events
end

class Event < ActiveRecord::Base
  belongs_to :user
  belongs_to :client
end

Problem: Should the associations for cashbox be polymorphic or has_many :through?

They way I understand it using polymorphic; events, other_charges & expenses could be cashboxable. The downside to this is I understand I can't sum over polymorphic associations?

With has_many through I am confused how to associate this, it seems complicated. But I could be missing something.

Clay Clay · Accepted Answer · 2012-08-29T20:08:17

class User < ActiveRecord::Base
  has_many :clients
  has_many :events
end

class Client < ActiveRecord::Base
  belongs_to :user, through: :events
  has_many :events
end

class Event < ActiveRecord::Base
  belongs_to :user
  belongs_to :client
end

Polymorphic or has_many :through for recording cash flow

1 Answers