module Slug
  module InstanceMethods
    def before_create
      self.slug = create_slug name.dup
      super
    end

    def before_update
      self.slug = create_slug name.dup
      super
    end

    private

    def create_slug ret
      #blow away apostrophes
      ret.gsub! /['`]/,""

      # @ --> at, and & --> and
      ret.gsub! /\s*@\s*/, " at "
      ret.gsub! /\s*&\s*/, " and "

      #replace all non alphanumeric, underscore or periods with hyphen
       ret.gsub! /\s*[^A-Za-z0-9\.]\s*/, '-'

       #convert double hyphens to single
       ret.gsub! /_+/,"-"

       #strip off leading/trailing hyphen
       ret.gsub! /\A[-\.]+|[-\.]+\z/,""

       ret
    end
  end
end