PHP SOAP not including my parameters in request - php

Question

I'm trying to access the HelloWorldCredentials service on
https://statistik.uni-c.dk/instregws/DataServiceXML.asmx?op=HelloWorldCredentials
I have the necessary credentials.
As far as I can see, I need to submit an array called "Credentials" containing one array containing two strings, one called "Username" and one called "Password".
I build my array like this:
$params = array(
"Credentials" => array(
"Username" => "Obviously",
"Password" => "NotPublic",
)
);
However, when I execute
$client = new SoapClient("https://statistik.uni-c.dk/instregws/DataServiceXML.asmx?wsdl", array('trace' => 1));
$params = array(
"Credentials" => array(
"Username" => "Obviously",
"Password" => "NotPublic",
)
);
$response = $client->__soapCall("HelloWorldCredentials", array($params));
echo("*** PARAMS ***\n");
var_dump( $params );
echo("\n*** REQUEST ***\n");
echo( $client->__getLastRequest() );
echo("\n*** RESPONSE ***\n");
var_dump( $response );
I get
*** PARAMS ***
array(1) {
["Credentials"]=>
array(2) {
["Username"]=>
string(11) "Obviously"
["Password"]=>
string(8) "NotPublic"
}
}
-as I should, but
*** REQUEST ***
<?xml version="1.0" encoding="UTF-8"?>
<SOAP-ENV:Envelope xmlns:SOAP-ENV="http://schemas.xmlsoap.org/soap/envelope/" xmlns:ns1="http://statistik.uni-c.dk/instreg/">
<SOAP-ENV:Body>
<ns1:HelloWorldCredentials/>
</SOAP-ENV:Body>
</SOAP-ENV:Envelope>
So obviously I get
*** RESPONSE ***
object(stdClass)#3 (1) {
["HelloWorldCredentialsResult"]=>
string(19) "Missing credentials"
}
Why are my parameters completely absent from the request?

Answer 1

according to the WSDL for the HelloWorldCredentials method you need to send the Credentials in the Header not the Body of the soap Envelope
so this should work:
<?php
$client = new SoapClient("https://statistik.uni-c.dk/instregws/DataServiceXML.asmx?wsdl", array('trace' => 1));
$credentials = array(
'Username' => 'Obviously',
'Password' => 'NotPublic'
);
$header = new SoapHeader('http://statistik.uni-c.dk/instreg/', 'Credentials', $credentials);
$client->__setSoapHeaders($header);
$response = $client->HelloWorldCredentials();
echo("\n*** REQUEST ***\n");
echo( $client->__getLastRequest() );
echo("\n*** RESPONSE ***\n");
var_dump( $response );