orbit4-5/app/models/concerns/slug.rb

 module Slug
  extend ActiveSupport::Concern

  included do
    before_create :generate_uid
  end

  def to_param
    [self.title.gsub(/[ "'*@#$%^&()+=;:.,?>|\\<~_!]/,'-').gsub(/-{2,}/,'-'), self.uid].join("-")
  end

  private

  def generate_uid
    self.uid = rand(36**8).to_s(36)
  end
end