Application_Form/app/models/application_form_setting.rb

class ApplicationFormSetting
  include Mongoid::Document
  include Mongoid::Timestamps

  field :reviewer_length, default: 3, :type=> Integer
  field :last_serial_number, :type => Integer, :default => 0
  def self.get_one
    s = self.first
    s = self.create if s.nil?
    s
  end
end