命名范围扩展 - 在Do Block之外调用方法

  named_scope :all_stars, :joins => [:all_stars] do
    def overall
      self.find(:all, :conditions => ['recordable_type = ?', 'User'])
    end
  end

  named_scope :all_stars, :joins => [:all_stars] do
    def overall
      overall_all_stars_condition
    end
  end

  def overall_all_stars_condition
    self.find(:all, :conditions => ['recordable_type = ?', 'User']) 
  end

named_scope :all_stars, :joins => [:all_stars]
named_scope :overall, :conditions => ['recordable_type = ?', 'User']

object.all_stars.overall.all
object.overall.all_stars.find(:all)
# etc

def overall_all_stars_condition
  self.all_stars.overall.all
end