Stack level too deep problem

Hi

I am getting a Stack level too deep error when i try creating a new
critical process object:

here is the code:

class Role < ActiveRecord::Base
  has_many :authorizations
  has_many :critical_processes, :through => :authorizations
  has_many :assignments
  has_many :users, :through => :assignments
end

class CriticalProcess < ActiveRecord::Base
  has_many :authorizations
  has_many :roles, :through => :authorizations, :dependent => :destroy,
:primary_key => :cp_secondary_id

  after_create :new_cp

  def create_roles
    self.roles.create :name => "#{self.cp_title} edit",
:critical_process_id => self.id, :edit => true, :review => false
    self.roles.create :name => "#{self.cp_title} review",
:critical_process_id => self.id, :edit => false, :review => true
  end

  def set_secondary_id
      self.update_attribute :cp_secondary_id, self.id
  end

  def new_cp
    if self.cp_secondary_id.blank?
      set_secondary_id
      create_roles
    end
  end
end

here is the error from the log:

SystemStackError (stack level too deep):
  app/models/critical_process.rb:17:in `create_roles'
  app/models/critical_process.rb:31:in `new_cp'
  app/controllers/critical_processes_controller.rb:61:in `create'
  app/controllers/critical_processes_controller.rb:60:in `create'

The issue is arising when the "create_roles" method is getting called.
Anyone know how i can fix this problem, i am new to rails and web
development. what changes would i have to make?

Thank You

Your associations are incorrect. Both Role and CriticalProcess refer
to each other via has_many -- one of them must use belongs_to. And
where is the Authorization class? What is it's relationship to
CriticalProcess?

Fix the associations problem and the loop will likely go away.

Why? I suspect because the CriticalProcess has_many :roles implies
that Role belongs_to it. Thus, ActiveRecord creates its own
create_roles for you. See
http://api.rubyonrails.org/classes/ActiveRecord/Associations/ClassMethods.html#method-i-has_many.
Notice the methods you get for free with each kind of assocation.

Nothing will work the way you have it defined now.

Martin

This is the problem - internally, update_attribute calls save on the
Role object while it's still in the first save transaction and
new_record? is still set. This triggers the after_create callback
again, and boosh - you've got a stack overflow.

I don't think the :primary_key option is going to work on the :through
association, though; what does the Authorization join model look like,
and how are the three linked together?

--Matt Jones