PHP SoapClient sends escaped XML characters - php

Question

I create an XML document using PHP's XMLWriter.
$xmlWriter = new \XMLWriter();
$xmlWriter->openMemory(); //generate XML in-memory, not on disk
//Please keep the indentation intact to preserve everybody's sanity!
$xmlWriter->startElement('RootElement');
// ...
$xmlWriter->endElement();
$myXml = $xmlWriter->outputMemory(true);
Now I connect to a SOAP service in non-WSDL mode.
$soapClient = new \SoapClient(null, array(
"location" => "https://theservice.com:1234/soap/",
"uri" => "http://www.namespace.com",
"trace" => 1
)
);
$params = array(
new \SoapParam($myXml, 'param')
);
$result = $soapClient->__soapCall('method', $params);
The problem is that the SOAP message received by the SOAP service contains my data as escaped XML characters. (Warning : dummy SOAP message ahead!)
<SOAP-ENV:Envelope xmlns:SOAP-ENV="http://schemas.xmlsoap.org/soap/envelope" ...>
<SOAP-ENV:Header>
...
</SOAP-ENV:Header>
<SOAP-ENV:Body>
<ns1:method>
<Request xsi:type="xsd:string">
<Root>
(escaped data)
</Root>
</Request>
</ns1:method>
</SOAP-ENV:Body>
</SOAP-ENV:Envelope>
The SOAP service will not work with escaped data but, on the other hand, I don't escape my data, the SoapClient does so. How do I make my SoapClient send unescaped data?

Answer 1

Escaping characters is the expected behavior of the XmlWriter::writeElement method.
It took me a while to figure it out but the answer was simple : put a SoapVar with the XSD_ANYXML parameter into the SoapParam :
$params = array(
new \SoapParam(new \SoapVar($myXml, XSD_ANYXML), 'param')
);
The SoapVar documentation mentions that its second parameter (encoding) can be "one of the XSD_... constants" which are not documented in the PHP docs.