orbit-basic/app/models/snippet.rb

class Snippet
  
   include MongoMapper::Document
  
   key :name, String, :required => true, :index => true
   key :full_name, String, :required => true, :index => true
   
   key :parent_id, ObjectId, :required => true, :index => true
   
   key_i18n :content, String
   
   before_validation :setup_default_value
   validates_uniqueness_of :name, :scope => :parent_id
   
   belongs_to :parent, :class_name => "Snippet", :foreign_key => :parent_id
     
   attr_writer :parent_name
   def parent_name
     self.parent.name
   end
        
   protected

   def ancestors
     node, nodes = self, []
     nodes << node = node.parent while !node.parent.blank?
     nodes.reverse
   end
   
   def setup_default_value
     self.parent_id = Item.find_by_name( self.parent_name ).id
     
     full_node = self.ancestors.map{ |a| a.name }.push( self.name )
     full_node.shift if full_node.size >= 2
     self.full_name = full_node.join("/")
   end   
   
end