QueryPath\DOMQuery::xml PHP Метод

    public function xml($markup = null)
    {
        $omit_xml_decl = $this->options['omit_xml_declaration'];
        if ($markup === true) {
            // Basically, we handle the special case where we don't
            // want the XML declaration to be displayed.
            $omit_xml_decl = true;
        } elseif (isset($markup)) {
            if ($this->options['replace_entities']) {
                $markup = \QueryPath\Entities::replaceAllEntities($markup);
            }
            $doc = $this->document->createDocumentFragment();
            $doc->appendXML($markup);
            $this->removeChildren();
            $this->append($doc);
            return $this;
        }
        $length = $this->size();
        if ($length == 0) {
            return;
        }
        // Only return the first item -- that's what JQ does.
        $first = $this->getFirstMatch();
        // Catch cases where first item is not a legit DOM object.
        if (!$first instanceof \DOMNode) {
            return;
        }
        if ($first instanceof \DOMDocument || $first->isSameNode($first->ownerDocument->documentElement)) {
            return $omit_xml_decl ? $this->document->saveXML($first->ownerDocument->documentElement) : $this->document->saveXML();
        }
        return $this->document->saveXML($first);
    }