Yoast_Product::get_file PHP Method

        public function get_file()
        {
            /*
             * Fall back to the slug for BC reasons.
             *
             * We used to pass the file to the slug field, but this isn't supported with the shiny updates in WordPress.
             * WordPress uses the slug in the HTML as an ID and a slash isn't a valid
             */
            return empty($this->file) ? $this->slug : $this->file;
        }