XPlan Search QueryXML Issue

<style>
pre {max-height: 400px; overflow: auto; background-color: #EEEEEE;}
div {border: solid 2px black;}
.error {border: solid 1px red;}
.notice {border: solid 1px blue;}
.success { border: solid 1px green;}
</style>
<?php

class XMLCurler
{
    public $username = '[redacted]';
    public $password = '[redacted]';
    public $url = 'https://amp.xplan.iress.com.au/RPC2/';
    public $ch;     // the curl handle
    public $token;
    public $results;

    public function __construct() {
        if ($this->connect()) {
            if ($this->login()) {
                echo "<div class=\"success\">Successful Connection & Login. Token: {$this->token}</div>";
            }
        }
    }

    public function __destruct() {
        if ($this->ch) {
            $this->disconnect();
        }
    }

    public function connect() {
        if (!$this->ch = curl_init($this->url)) { // generate curl handle
            echo "<div class=\"error\">CURL Error While Connecting (check url)";
            return false;
        }
        return true;
    }

    public function disconnect() {
        curl_close($this->ch);
    }

	public function processResponse($response) {
		if (!$response) {
			echo "<div class=\"error\">CURL Error While Attempting to Login - No XML token string<br><b>" , curl_error($this->ch) , "</b></div>";
            return false;
		}
		$decoded = xmlrpc_decode($response);
		if (is_array($decoded) && xmlrpc_is_fault($decoded)) {
            echo "<div class=\"error\">Error Response: {$decoded['faultString']} ({$decoded['faultCode']})</div>";
            return false;
        }
		return $decoded;
	}

    public function login() {
        $postfields = xmlrpc_encode_request('edai.Login', array($this->username, $this->password));  // package as xml
        curl_setopt($this->ch, CURLOPT_HTTPHEADER, array('Content-Type: text/xml'));
        curl_setopt($this->ch, CURLOPT_RETURNTRANSFER, true);
        curl_setopt($this->ch, CURLOPT_POSTFIELDS, $postfields);
        curl_setopt($this->ch, CURLOPT_SSL_VERIFYHOST, 0);      // not advised, I need to find out how to avoid this
        curl_setopt($this->ch, CURLOPT_SSL_VERIFYPEER, 0);      // not advised, I need to find out how to avoid this

        if (!$token = $this->processResponse(curl_exec($this->ch))) {
			return false;
		}
		if (!preg_match("~^[\w+]{20}$~", $token)) {
			echo "<div class=\"error\">Invalid/Unexpected Token Generated<br><b>$token</b>";
			return false;
        }
        $this->token = $token;  // cache the valid token
        return true;
    }

    public function listChildren($path) {
        $method = "edai.ListChildren";
        $request = xmlrpc_encode_request($method, array($this->token, $path));

        echo "<div class=\"notice\">XMLRPC Encoded Request (for $method): <pre>" , htmlentities($request) , "</pre></div>";

        curl_setopt($this->ch, CURLOPT_POSTFIELDS, $request);
        if (!$results = $this->processResponse(curl_exec($this->ch))) {
			return false;
		}
        $this->results = $results;  // cache the valid results
        return true;
    }


    public function search($basepath, $queryxml) {
        $method = "edai.Search";

		/** Desperate/Manual xml construction ...
         * $xml = new DOMDocument("1.0", "utf-8");
         * $xml->appendChild($methodCall = $xml->createElement("methodCall"));
         * $methodCall->appendChild($methodName = $xml->createElement("methodName"));
         * $methodCall->appendChild($params = $xml->createElement("params"));

         * $params->appendChild($param1 = $xml->createElement("param"));
         * $param1->appendChild($value1 = $xml->createElement("value"));
         * $value1->appendChild($string1 = $xml->createElement("string"));

         * $params->appendChild($param2 = $xml->createElement("param"));
         * $param2->appendChild($value2 = $xml->createElement("value"));
         * $value2->appendChild($string2 = $xml->createElement("string"));

         * $params->appendChild($param3 = $xml->createElement("param"));
         * $param3->appendChild($value3 = $xml->createElement("value"));
         * $value3->appendChild($string3 = $xml->createElement("string"));
         * $string3->appendChild($EntitySearch = $xml->createElement("EntitySearch"));
         * $EntitySearch->appendChild($SearchResult1 = $xml->createElement("SearchResult"));
         * $SearchResult1->setAttribute("field", "first_name");

         * $EntitySearch->appendChild($SearchResult2 = $xml->createElement("SearchResult"));
         * $SearchResult2->setAttribute('field', "last_name");

         * $EntitySearch->appendChild($SearchQuick = $xml->createElement("SearchQuick"));
         * $SearchQuick->appendChild($s = $xml->createElement("s"));

         * $xpath = new DOMXPath($xml);
         * $result1 = $xpath->query("//methodName");
         * $result1->item(0)->nodeValue = $method;

         * $result2 = $xpath->query("//params/param[1]/value/string");
         * $result2->item(0)->nodeValue = $this->token;
         * $result3 = $xpath->query("//params/param[2]/value/string");
         * $result3->item(0)->nodeValue = "entitymgr/client";

         * $result4 = $xpath->query("//SearchQuick/s");
         * $result4->item(0)->nodeValue = "last_name:Smith";

         * $xml->formatOutput = true;
         * $request = $xml->saveXML();
		 */

		 /** Desperately attempted passing array ...
		  * $queryarray = array(
		  * 	"EntitySearch" => array(
		  * 		array(
		  * 			"SearchResult" => array(
		  * 				"@attr" => array(
		  * 			"field" => "first_name"
		  * 				)
		  * 			)
		  * 		),
		  * 			array(
		  * 			"SearchResult" => array(
		  * 				"@attr" => array(
		  * 					"field" => "last_name"
		  * 				)
		  * 			)
		  * 		),
		  * 		array(
		  * 			"SearchQuick" => array(
		  * 				"s" => "last_name:Smith"
		  * 			)
		  * 		)
		  * 	)
		  * );
		  */

		$request = xmlrpc_encode_request($method, array($this->token, $basepath, $queryxml));  // this mutates the nest $queryxml string
			// Causes:
				//Error Response: UNKNOWN(CORBA.UNKNOWN(omniORB.UNKNOWN_PythonException, CORBA.COMPLETED_MAYBE)) (-32505)
		//$request = html_entity_decode($request);  // repair encoded entities
		//$request = preg_replace('~(?:>\K\s+)|(?:\s+(?=<))~', '', $request);  // strip every whitespace character between tags (hack)
			// Causes:
				// Error Response: ExpatError(syntax error: line 1, column 0 (byte 0)) (-32505)
        echo "<div class=\"notice\">XMLRPC Encoded Request (for $method): <pre>" , htmlentities($request) , "</pre></div>";

		curl_setopt($this->ch, CURLOPT_POSTFIELDS, $request);
        if (!$results = $this->processResponse(curl_exec($this->ch))) {
			return false;
		}
        $this->results = $results;  // cache the valid results
        return true;
    }
}

$XC = new XMLCurler();

/* edai.ListChildren works as desired/expected */
$path = "/entitymgr/client";
if ($XC->listChildren($path)) {
    echo "<div>List of Children Successful.<pre>";
    var_export($XC->results);
    echo "</pre></div>";
}

/* edai.Search does not work */
$basepath = "entitymgr/client";
$queryxml = <<<XML
<EntitySearch>
 <SearchResult field="first_name"/>
 <SearchResult field="last_name"/>
 <SearchQuick><s>last_name:Smith</s></SearchQuick>
</EntitySearch>
XML;
if ($XC->search($basepath, $queryxml)) {
    echo "<div>Search Successful.<pre>";
    var_export($XC->results);
    echo "</pre></div>";
}