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 => "Item", :foreign_key => :parent_id attr_accessor :parent_name def parent_name @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 || 'root' ).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