gistfile1.txt

class Photo
  include Mongoid::Document
  include Mongoid::Timestamps # adds created_at and updated_at fields

  # fields
  field :caption,     :type => String
  field :tags,        :type => Array,   :default => []
 
 before_save :make_tags
  

  # fix tag
  def make_tags
    self.tags = self.tags.split(",") if self.tags.is_a?(String)
  end
  
end