gistfile1.rb

  def after_save
    unless @skip_callbacks
      import_products_by_id(self.product_ids_for_import) if should_import_products?
      import_keywords(keywords_for_import) if should_import_keywords?
      import_product_ads_by_id(ad_ids_for_import) if should_import_ads?
    
      campaign_products_to_product_ids_delimited if should_update_product_ids_delimited?
      campaign_keywords_to_keywords_delimited if should_update_keywords_delimited?
      campaign_ads_to_ad_ids_delimited if should_update_ad_ids_delimited?
    end
  end

  def campaign_products_to_product_ids_delimited
    @should_update_product_ids_delimited = false
    skip_callbacks do 
      update_attribute(:product_ids_delimited, self.campaign_products.find(:all).collect(&:product_id).join(DELIMITER))
    end
  end

  def skip_callbacks(&b)
    @skip_callbacks = true and yield b and @skip_callbacks = false
  end