undefined method self_and_descendants_from_active_record

undefined method self_and_descendants_from_active_record.rb

=begin
Upgraded to rails 2.3.4 and got the following error:

undefined method self_and_descendants_from_active_record for Class:Object

My class doesn't descend from ActiveRecord but I was using ActiveRecord::Errors for validations

attr_accessor :errors
def initialize
  #this hack is to get an instance of ActiveRecord::Errors:
  self.errors = ActiveRecord::Errors.new(Object.new)
end

And I overerride the valid? method.

But now I get the undefined method error.

This page had the work around but the html encoding made it unusable:
http://puretec.wordpress.com/2009/09/09/activerecorderrors-newself-and-undefined-method-self_and_descendants_from_active_record/#comment-17

Below is the code I added to my class to restore the previous functionality.
=end
 def self.self_and_descendants_from_active_record
   [self]
 end
 def human_attribute_name(attribute_key_name, options = {})
   defaults = self_and_descendants_from_active_record.map do |klass|
     "#{klass.name.underscore}.#{attribute_key_name}""#{klass.name.underscore}.#{attribute_key_name}"
   end
   defaults << options[:default] if options[:default]
   defaults.flatten!
   defaults << attribute_key_name.humanize
   options[:count] ||= 1
   I18n.translate(defaults.shift, options.merge(:default => defaults, :scope => [:activerecord, :attributes]))
 end
 def human_name(options = {})
   defaults = self_and_descendants_from_active_record.map do |klass|
     "#{klass.name.underscore}""#{klass.name.underscore}"
   end 
   defaults << self.name.humanize
   I18n.translate(defaults.shift, {:scope => [:activerecord, :models], :count => 1, :default => defaults}.merge(options))
 end