gistfile1.rb

module FilterableResource
  def acts_as_filterable(options = {})
    cattr_accessor :testing
    self.testing = 'testing'

    self.named_scope :filtered_from, lambda { |params|
      puts('!!![' + self.testing.to_s + ']!!!')
      nil
    }
  end
end

ActiveRecord::Base.extend FilterableResource