/** * Convert the request data into XML. * * @since 4.3.0 * @return string */ protected function to_xml() { if (!empty($this->request_xml)) { return $this->request_xml; } $this->xml = new XMLWriter(); // Create XML document in memory $this->xml->openMemory(); // Set XML version & encoding $this->xml->startDocument('1.0', 'UTF-8'); $request_data = $this->get_request_data(); SV_WC_Helper::array_to_xml($this->xml, $this->get_root_element(), $request_data[$this->get_root_element()]); $this->xml->endDocument(); return $this->request_xml = $this->xml->outputMemory(); }