publishable.rb

module Model
  module Publishable
    PUBLISHING_STATUSES = %w(published approved deleted).freeze
    extend ActiveSupport::Concern

    included do
      PUBLISHING_STATUSES.each do |status|
        define_method "is_#{status}?" do
          self.publishing_status == status
        end
      end

      validates :publishing_status, inclusion: PUBLISHING_STATUSES

      scope :published_as, (Proc.new do |*statuses|
        where(publishing_status: fetch_publishing_status_ids(*statuses))
      end)
    end

    module ClassMethods 
      def fetch_publishing_status_ids(*args)
        args.map {|status| PUBLISHING_STATUSES.index(status.to_s)}
      end

      def fetch_publishing_statuses(*args)
        args.map {|status_id| PUBLISHING_STATUSES.at status_id}
      end
    end

    def publishing_status=(status)
      status_id = self.class.fetch_publishing_status_ids(status).first
      write_attribute(:publishing_status, status_id)
    end

    def publishing_status
      self.class.fetch_publishing_statuses(read_attribute(:publishing_status)).first
    end

    def destroy(force = false)
      if force
        super()
      else
        self.publishing_status = :deleted
        self.save
      end
    end
  end
end