Factory Pattern in Ruby/RoR

I've observed and repeated the factory design detailed at artima - Modular Architectures with Ruby but I would like something a little cleaner.

The details are such that I have 3 types of users: managers, employees and customers.

I've abstracted the user security API such that Manager < User Employee < User Customer < User and the User class has all of the authentication methods such as "set_password", "check_password", etc.

Now, for the authentication controller.

I have my route mapping such that /authenticate/:user_type/:action

I'd like to have something similar to the following as my authentication code:

class Authenticate < ActionController::Base

def authenticate   @user = User.find(@params[:user_type], @params[:user][:email_address])   if @user and @user.check_password(@params[:user][:password])     render(:text => "Success")   else     render(:text => "Failure")   end end

end

Make sense? Any thoughts/ideas appreciated.

Thank you! Dave Hawkins