validation of nested polymorphic class

I have Admin class & User class and a polymorphic Profile class

class Admin < ActiveRecord::Base
  include ActiveModel::Validations
  has_one :profile, :as => :profitable
  accepts_nested_attributes_for :profile
  validates_associated :profile

class User < ActiveRecord::Base
  include ActiveModel::Validations
  has_one :profile, :as => :profitable

class Profile < ActiveRecord::Base
  belongs_to :profilable, :polymorphic => true
  validates :title, :first_name, :last_name , :presence => true, :if
=>Proc.new { |p| p[:profilable_type] == "Admin" }

I am trying to validates a new Admin form with nested attributes
but I don't need the profile validation for the User class,
I wrote a validation in the Profile class with a Proc block to test
the profilable_type, but it's not working ....
is there another way to try ?

Maybe(??) there is a mix-up between “profitable” and “profilable”,
or is that intentional?

HTH,

Peter

Thanks Peter .. just a typing error in my post , actually it's well
written in the models : has_one :profile, :as => :profitable ( even
if profitable would make $$)

the params sent from the form submit are OK

{.. "admin"=>{"area_id"=>"1", "canAdministrate"=>"0",
"canManageProject"=>"0", "canShootVideo"=>"0", "canEditVideo"=>"0",
"email"=>"", "password"=>"", "password_confirmation"=>"",
"profile"=>{"first_name"=>"", "middle_name"=>"", "last_name"=>"",
"phone"=>"", "mobile"=>"", "address"=>""}},
"commit"=>"Enregistrer", "action"=>"create", "controller"=>"backoffice/
admins"}

you can see params[:admin] and params[:admin][:profile]
in the edit action, if I execute a
@admin = Admin.new(params[:admin])
@admin.valid? => false
@admin.errors = #<ActiveModel::Errors:0x007fde974fc928 @base=#<Admin
id: ....@messages={:email=>["doit être rempli(e)"], :password=>["doit
être rempli(e)"]}
I get only the email and password errors even with a validation in the
Profile model
validates :title, :first_name, :last_name , :presence => true