Scalr\Service\Aws\Client\SoapClient::_processTransforms PHP Method

    protected function _processTransforms($refNode, $objData)
    {
        $data = $objData;
        $xpath = new \DOMXPath($refNode->ownerDocument);
        $xpath->registerNamespace('secdsig', self::XMLDSIGNS);
        $query = './secdsig:Transforms/secdsig:Transform';
        $nodelist = $xpath->query($query, $refNode);
        $canonicalMethod = 'http://www.w3.org/TR/2001/REC-xml-c14n-20010315';
        $arXPath = null;
        $prefixList = null;
        foreach ($nodelist as $transform) {
            $algorithm = $transform->getAttribute("Algorithm");
            switch ($algorithm) {
                case 'http://www.w3.org/2001/10/xml-exc-c14n#':
                case 'http://www.w3.org/2001/10/xml-exc-c14n#WithComments':
                    $node = $transform->firstChild;
                    while ($node) {
                        if ($node->localName == 'InclusiveNamespaces') {
                            if ($pfx = $node->getAttribute('PrefixList')) {
                                $arpfx = array();
                                $pfxlist = split(" ", $pfx);
                                foreach ($pfxlist as $pfx) {
                                    $val = trim($pfx);
                                    if (!empty($val)) {
                                        $arpfx[] = $val;
                                    }
                                }
                                if (count($arpfx) > 0) {
                                    $prefixList = $arpfx;
                                }
                            }
                            break;
                        }
                        $node = $node->nextSibling;
                    }
                case 'http://www.w3.org/TR/2001/REC-xml-c14n-20010315':
                case 'http://www.w3.org/TR/2001/REC-xml-c14n-20010315#WithComments':
                    $canonicalMethod = $algorithm;
                    break;
                case 'http://www.w3.org/TR/1999/REC-xpath-19991116':
                    $node = $transform->firstChild;
                    while ($node) {
                        if ($node->localName == 'XPath') {
                            $arXPath = array();
                            $arXPath['query'] = '(.//. | .//@* | .//namespace::*)[' . $node->nodeValue . ']';
                            $arXpath['namespaces'] = array();
                            $nslist = $xpath->query('./namespace::*', $node);
                            foreach ($nslist as $nsnode) {
                                if ($nsnode->localName != "xml") {
                                    $arXPath['namespaces'][$nsnode->localName] = $nsnode->nodeValue;
                                }
                            }
                            break;
                        }
                        $node = $node->nextSibling;
                    }
                    break;
            }
        }
        if ($data instanceof \DOMNode) {
            $data = $this->_canonicalizeData($objData, $canonicalMethod, $arXPath, $prefixList);
        }
        return $data;
    }