accepts_nested_attributes_for with belongs_to polymorphic devise - ruby-on-rails

Question

I have 3 models and this associations for them
class User < ActiveRecord::Base
# devise modules here
attr_accessible :email, :password, :password_confirmation, :remember_me, :rolable_id, :rolable_type
belongs_to :rolable, :polymorphic => true
end
class Player < ActiveRecord::Base
attr_accessible :age, :name, :position
has_one :user, :as => :rolable
end
class Manager < ActiveRecord::Base
attr_accessible :age, :name
has_one :user, :as => :rolable
end
I'm out of the box from rails way to put accepts_nested_attributes_for :rolable on user model and In this accepts_nested_attributes_for with belongs_to polymorphic question I found some solutions for it but all solution not works for me. All solutions, always the same error when I try to create a user
Processing by RegistrationsController#create as HTML
Parameters: {"utf8"=>"V", "authenticity_token"=>"WKCniJza+PS5umMWCqvxFCZaRVQMPZBT4nU2fl994cU=", "user"=>{"email"=>"john#email.com", "password"=>"[FILTERED]", "password_confirmation"=>"[FILTERED]", "rolable_type"=>"manager", "rolable"=>{"name"=>"john", "age"=>"24"}}, "commit"=>"Sign up"}
Completed 500 Internal Server Error in 143.0ms
NoMethodError (undefined method `primary_key' for ActiveSupport::HashWithIndifferentAccess:Class):
app/controllers/registrations_controller.rb:13:in `new'
app/controllers/registrations_controller.rb:13:in `create'

Answer 1

My mistake, I'm use nested form
<%= f.fields_for :rolable do |rf| %>
....
<% end %>
change to
<%= f.fields_for :rolable_attributes do |rf| %>
....
<% end %>

Answer 2

for polymorphic association you have to maintain generic model Roll like
class User < ActiveRecord::Base
# devise modules here
attr_accessible :email, :password, :password_confirmation, :remember_me
has_many :rolls, :as => :rolable
end
class Player < ActiveRecord::Base
attr_accessible :age, :name, :position
has_many :rolls, :as => :rolable
end
class Manager < ActiveRecord::Base
attr_accessible :age, :name
has_many :rolls, :as => :rolable
end
class Roll < ActiveRecord::Base
attr_accessible :rolable_id, :rolable_type
belongs_to :rolable, :polymorphic=> true
end