orbit-4-1/app/models/layout.rb

class Layout
   
   include Mongoid::Document
   
   field :name, :index => true
   field :description
   field :content
   
   references_many :children, :class_name => "Item"
   
   validates_presence_of :name
   validates_format_of :name, :with => /^[0-9a-zA-Z\-_]+$/
   validates_uniqueness_of :name
   
   def self.exist_one?
      Layout.count > 0
   end
   
end