gistfile1.rb

class Domain < ActiveRecord::Base
  named_scope :length, lambda {|length| {:conditions => ["length = ?", length]} if !length.blank? || length == 'all'}
  named_scope :viewable, lambda {{:conditions => ["viewable_at < ?", Time.now.utc]}}
  named_scope :public, lambda {|public| {:conditions => ["public = ?", true]} if !public.blank?}
end

  def self.search(options = {})
    self.length(options[:length]).viewable.public(options[:public])
  end