Best way to sort through a polymorphic association

Question

So - having the following setup:

class Event < ActiveRecord::Base
 has_many :invitations
end

class Invitation < ActiveRecord::Base
  belongs_to :guest, :polymorphic => true
  belongs_to :event
end

class Member > ActiveRecord::Base
  has_many :invitations, :as => :guest

  def full_name
    [first_name, last_name].join(" ")
  end
end

class Visitor > ActiveRecord::Base
  has_many :invitations, :as => :guest

  def full_name
    name
  end
end

In the end, I want to be able to fetch an Events invitations ordered by the Guests full_name. I can't figure out how - anyone who can help me solve this? Would be greatly appreciated :)

Answer 1

As far as full_name is a virtual attributes I can imagine only ruby solution, not sql

event = Event.find some event
event.invitations.sort_by(&:full_name)