callmez\wechat\sdk\components\BaseWechat::xml PHP Метод

    public function xml(array $data, $charset = null)
    {
        $dom = new DOMDocument('1.0', $charset === null ? Yii::$app->charset : $charset);
        $root = new DOMElement('xml');
        $dom->appendChild($root);
        $this->buildXml($root, $data);
        $xml = $dom->saveXML();
        return trim(substr($xml, strpos($xml, '?>') + 2));
    }