user_extension.rb

module KeepUp
  module Permissions
    module UserExtension
	    def self.included(klass) 
    		klass.class_eval do
    			has_one :permission, :as => :authorizable						
    			has_and_belongs_to_many :roles, :join_table => :user_roles
  			
  		    alias :can? :has_permission?
  		    
  		    after_create :create_new_permission
  		    
  		    attr_protected :permission_attributes,:role_attributes,:role_ids
  		    accepts_nested_attributes_for :permission, :roles
    		end
    	end
		
      def plays role
        role = role.to_s if role.is_a? Symbol
        r = Role.find_by_name role.downcase
        raise "#{role} does not exist." if r.nil?
        roles << r
        true
      end
      
      def plays? role
        role = role.to_s if role.is_a? Symbol
        raise "#{role} does not exist" if Role.find_by_name(role.downcase).nil?
        roles.find_by_name(role.downcase) != nil
      end
      
      def does_not_play? role
        !plays? role
      end

      def has_permission? perm
        return true if has_local_permission? perm
        roles.each do |role|
          return true if role.has_local_permission? perm
        end
        false            
      end
      
      private      
      def roles_attributes=(attributes)        
        keys = []
        attributes.each_value do |value|
          keys << value unless value.nil?
        end
        self.role_ids = keys    
      end
    end  
  end
end