Wordpress/wp-includes/class-IXR.php
2012-01-08 17:01:11 +00:00

1064 lines
31 KiB
PHP

<?php
/**
* IXR - The Incutio XML-RPC Library
*
* Copyright (c) 2010, Incutio Ltd.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* - Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
* - Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* - Neither the name of Incutio Ltd. nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
* IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
* THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
* OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE
* USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* @package IXR
* @since 1.5
*
* @copyright Incutio Ltd 2010 (http://www.incutio.com)
* @version 1.7.4 7th September 2010
* @author Simon Willison
* @link http://scripts.incutio.com/xmlrpc/ Site/manual
* @license http://www.opensource.org/licenses/bsd-license.php BSD
*/
/**
* IXR_Value
*
* @package IXR
* @since 1.5
*/
class IXR_Value {
var $data;
var $type;
function IXR_Value($data, $type = false)
{
$this->data = $data;
if (!$type) {
$type = $this->calculateType();
}
$this->type = $type;
if ($type == 'struct') {
// Turn all the values in the array in to new IXR_Value objects
foreach ($this->data as $key => $value) {
$this->data[$key] = new IXR_Value($value);
}
}
if ($type == 'array') {
for ($i = 0, $j = count($this->data); $i < $j; $i++) {
$this->data[$i] = new IXR_Value($this->data[$i]);
}
}
}
function calculateType()
{
if ($this->data === true || $this->data === false) {
return 'boolean';
}
if (is_integer($this->data)) {
return 'int';
}
if (is_double($this->data)) {
return 'double';
}
// Deal with IXR object types base64 and date
if (is_object($this->data) && is_a($this->data, 'IXR_Date')) {
return 'date';
}
if (is_object($this->data) && is_a($this->data, 'IXR_Base64')) {
return 'base64';
}
// If it is a normal PHP object convert it in to a struct
if (is_object($this->data)) {
$this->data = get_object_vars($this->data);
return 'struct';
}
if (!is_array($this->data)) {
return 'string';
}
// We have an array - is it an array or a struct?
if ($this->isStruct($this->data)) {
return 'struct';
} else {
return 'array';
}
}
function getXml()
{
// Return XML for this value
switch ($this->type) {
case 'boolean':
return '<boolean>'.(($this->data) ? '1' : '0').'</boolean>';
break;
case 'int':
return '<int>'.$this->data.'</int>';
break;
case 'double':
return '<double>'.$this->data.'</double>';
break;
case 'string':
return '<string>'.htmlspecialchars($this->data).'</string>';
break;
case 'array':
$return = '<array><data>'."\n";
foreach ($this->data as $item) {
$return .= ' <value>'.$item->getXml()."</value>\n";
}
$return .= '</data></array>';
return $return;
break;
case 'struct':
$return = '<struct>'."\n";
foreach ($this->data as $name => $value) {
$name = htmlspecialchars($name);
$return .= " <member><name>$name</name><value>";
$return .= $value->getXml()."</value></member>\n";
}
$return .= '</struct>';
return $return;
break;
case 'date':
case 'base64':
return $this->data->getXml();
break;
}
return false;
}
/**
* Checks whether or not the supplied array is a struct or not
*
* @param unknown_type $array
* @return boolean
*/
function isStruct($array)
{
$expected = 0;
foreach ($array as $key => $value) {
if ((string)$key != (string)$expected) {
return true;
}
$expected++;
}
return false;
}
}
/**
* IXR_MESSAGE
*
* @package IXR
* @since 1.5
*
*/
class IXR_Message
{
var $message;
var $messageType; // methodCall / methodResponse / fault
var $faultCode;
var $faultString;
var $methodName;
var $params;
// Current variable stacks
var $_arraystructs = array(); // The stack used to keep track of the current array/struct
var $_arraystructstypes = array(); // Stack keeping track of if things are structs or array
var $_currentStructName = array(); // A stack as well
var $_param;
var $_value;
var $_currentTag;
var $_currentTagContents;
// The XML parser
var $_parser;
function IXR_Message($message)
{
$this->message =& $message;
}
function parse()
{
// first remove the XML declaration
// merged from WP #10698 - this method avoids the RAM usage of preg_replace on very large messages
$header = preg_replace( '/<\?xml.*?\?'.'>/', '', substr($this->message, 0, 100), 1);
$this->message = substr_replace($this->message, $header, 0, 100);
if (trim($this->message) == '') {
return false;
}
$this->_parser = xml_parser_create();
// Set XML parser to take the case of tags in to account
xml_parser_set_option($this->_parser, XML_OPTION_CASE_FOLDING, false);
// Set XML parser callback functions
xml_set_object($this->_parser, $this);
xml_set_element_handler($this->_parser, 'tag_open', 'tag_close');
xml_set_character_data_handler($this->_parser, 'cdata');
$chunk_size = 262144; // 256Kb, parse in chunks to avoid the RAM usage on very large messages
$final = false;
do {
if (strlen($this->message) <= $chunk_size) {
$final = true;
}
$part = substr($this->message, 0, $chunk_size);
$this->message = substr($this->message, $chunk_size);
if (!xml_parse($this->_parser, $part, $final)) {
return false;
}
if ($final) {
break;
}
} while (true);
xml_parser_free($this->_parser);
// Grab the error messages, if any
if ($this->messageType == 'fault') {
$this->faultCode = $this->params[0]['faultCode'];
$this->faultString = $this->params[0]['faultString'];
}
return true;
}
function tag_open($parser, $tag, $attr)
{
$this->_currentTagContents = '';
$this->currentTag = $tag;
switch($tag) {
case 'methodCall':
case 'methodResponse':
case 'fault':
$this->messageType = $tag;
break;
/* Deal with stacks of arrays and structs */
case 'data': // data is to all intents and puposes more interesting than array
$this->_arraystructstypes[] = 'array';
$this->_arraystructs[] = array();
break;
case 'struct':
$this->_arraystructstypes[] = 'struct';
$this->_arraystructs[] = array();
break;
}
}
function cdata($parser, $cdata)
{
$this->_currentTagContents .= $cdata;
}
function tag_close($parser, $tag)
{
$valueFlag = false;
switch($tag) {
case 'int':
case 'i4':
$value = (int)trim($this->_currentTagContents);
$valueFlag = true;
break;
case 'double':
$value = (double)trim($this->_currentTagContents);
$valueFlag = true;
break;
case 'string':
$value = (string)trim($this->_currentTagContents);
$valueFlag = true;
break;
case 'dateTime.iso8601':
$value = new IXR_Date(trim($this->_currentTagContents));
$valueFlag = true;
break;
case 'value':
// "If no type is indicated, the type is string."
if (trim($this->_currentTagContents) != '') {
$value = (string)$this->_currentTagContents;
$valueFlag = true;
}
break;
case 'boolean':
$value = (boolean)trim($this->_currentTagContents);
$valueFlag = true;
break;
case 'base64':
$value = base64_decode($this->_currentTagContents);
$valueFlag = true;
break;
/* Deal with stacks of arrays and structs */
case 'data':
case 'struct':
$value = array_pop($this->_arraystructs);
array_pop($this->_arraystructstypes);
$valueFlag = true;
break;
case 'member':
array_pop($this->_currentStructName);
break;
case 'name':
$this->_currentStructName[] = trim($this->_currentTagContents);
break;
case 'methodName':
$this->methodName = trim($this->_currentTagContents);
break;
}
if ($valueFlag) {
if (count($this->_arraystructs) > 0) {
// Add value to struct or array
if ($this->_arraystructstypes[count($this->_arraystructstypes)-1] == 'struct') {
// Add to struct
$this->_arraystructs[count($this->_arraystructs)-1][$this->_currentStructName[count($this->_currentStructName)-1]] = $value;
} else {
// Add to array
$this->_arraystructs[count($this->_arraystructs)-1][] = $value;
}
} else {
// Just add as a paramater
$this->params[] = $value;
}
}
$this->_currentTagContents = '';
}
}
/**
* IXR_Server
*
* @package IXR
* @since 1.5
*/
class IXR_Server
{
var $data;
var $callbacks = array();
var $message;
var $capabilities;
function IXR_Server($callbacks = false, $data = false, $wait = false)
{
$this->setCapabilities();
if ($callbacks) {
$this->callbacks = $callbacks;
}
$this->setCallbacks();
if (!$wait) {
$this->serve($data);
}
}
function serve($data = false)
{
if (!$data) {
if (isset($_SERVER['REQUEST_METHOD']) && $_SERVER['REQUEST_METHOD'] !== 'POST') {
header('Content-Type: text/plain'); // merged from WP #9093
die('XML-RPC server accepts POST requests only.');
}
global $HTTP_RAW_POST_DATA;
if (empty($HTTP_RAW_POST_DATA)) {
// workaround for a bug in PHP 5.2.2 - http://bugs.php.net/bug.php?id=41293
$data = file_get_contents('php://input');
} else {
$data =& $HTTP_RAW_POST_DATA;
}
}
$this->message = new IXR_Message($data);
if (!$this->message->parse()) {
$this->error(-32700, 'parse error. not well formed');
}
if ($this->message->messageType != 'methodCall') {
$this->error(-32600, 'server error. invalid xml-rpc. not conforming to spec. Request must be a methodCall');
}
$result = $this->call($this->message->methodName, $this->message->params);
// Is the result an error?
if (is_a($result, 'IXR_Error')) {
$this->error($result);
}
// Encode the result
$r = new IXR_Value($result);
$resultxml = $r->getXml();
// Create the XML
$xml = <<<EOD
<methodResponse>
<params>
<param>
<value>
$resultxml
</value>
</param>
</params>
</methodResponse>
EOD;
// Send it
$this->output($xml);
}
function call($methodname, $args)
{
if (!$this->hasMethod($methodname)) {
return new IXR_Error(-32601, 'server error. requested method '.$methodname.' does not exist.');
}
$method = $this->callbacks[$methodname];
// Perform the callback and send the response
if (count($args) == 1) {
// If only one paramater just send that instead of the whole array
$args = $args[0];
}
// Are we dealing with a function or a method?
if (is_string($method) && substr($method, 0, 5) == 'this:') {
// It's a class method - check it exists
$method = substr($method, 5);
if (!method_exists($this, $method)) {
return new IXR_Error(-32601, 'server error. requested class method "'.$method.'" does not exist.');
}
//Call the method
$result = $this->$method($args);
} else {
// It's a function - does it exist?
if (is_array($method)) {
if (!is_callable(array($method[0], $method[1]))) {
return new IXR_Error(-32601, 'server error. requested object method "'.$method[1].'" does not exist.');
}
} else if (!function_exists($method)) {
return new IXR_Error(-32601, 'server error. requested function "'.$method.'" does not exist.');
}
// Call the function
$result = call_user_func($method, $args);
}
return $result;
}
function error($error, $message = false)
{
// Accepts either an error object or an error code and message
if ($message && !is_object($error)) {
$error = new IXR_Error($error, $message);
}
$this->output($error->getXml());
}
function output($xml)
{
$xml = '<?xml version="1.0"?>'."\n".$xml;
$length = strlen($xml);
header('Connection: close');
header('Content-Length: '.$length);
header('Content-Type: text/xml');
header('Date: '.date('r'));
echo $xml;
exit;
}
function hasMethod($method)
{
return in_array($method, array_keys($this->callbacks));
}
function setCapabilities()
{
// Initialises capabilities array
$this->capabilities = array(
'xmlrpc' => array(
'specUrl' => 'http://www.xmlrpc.com/spec',
'specVersion' => 1
),
'faults_interop' => array(
'specUrl' => 'http://xmlrpc-epi.sourceforge.net/specs/rfc.fault_codes.php',
'specVersion' => 20010516
),
'system.multicall' => array(
'specUrl' => 'http://www.xmlrpc.com/discuss/msgReader$1208',
'specVersion' => 1
),
);
}
function getCapabilities($args)
{
return $this->capabilities;
}
function setCallbacks()
{
$this->callbacks['system.getCapabilities'] = 'this:getCapabilities';
$this->callbacks['system.listMethods'] = 'this:listMethods';
$this->callbacks['system.multicall'] = 'this:multiCall';
}
function listMethods($args)
{
// Returns a list of methods - uses array_reverse to ensure user defined
// methods are listed before server defined methods
return array_reverse(array_keys($this->callbacks));
}
function multiCall($methodcalls)
{
// See http://www.xmlrpc.com/discuss/msgReader$1208
$return = array();
foreach ($methodcalls as $call) {
$method = $call['methodName'];
$params = $call['params'];
if ($method == 'system.multicall') {
$result = new IXR_Error(-32600, 'Recursive calls to system.multicall are forbidden');
} else {
$result = $this->call($method, $params);
}
if (is_a($result, 'IXR_Error')) {
$return[] = array(
'faultCode' => $result->code,
'faultString' => $result->message
);
} else {
$return[] = array($result);
}
}
return $return;
}
}
/**
* IXR_Request
*
* @package IXR
* @since 1.5
*/
class IXR_Request
{
var $method;
var $args;
var $xml;
function IXR_Request($method, $args)
{
$this->method = $method;
$this->args = $args;
$this->xml = <<<EOD
<?xml version="1.0"?>
<methodCall>
<methodName>{$this->method}</methodName>
<params>
EOD;
foreach ($this->args as $arg) {
$this->xml .= '<param><value>';
$v = new IXR_Value($arg);
$this->xml .= $v->getXml();
$this->xml .= "</value></param>\n";
}
$this->xml .= '</params></methodCall>';
}
function getLength()
{
return strlen($this->xml);
}
function getXml()
{
return $this->xml;
}
}
/**
* IXR_Client
*
* @package IXR
* @since 1.5
*
*/
class IXR_Client
{
var $server;
var $port;
var $path;
var $useragent;
var $response;
var $message = false;
var $debug = false;
var $timeout;
var $headers = array();
// Storage place for an error message
var $error = false;
function IXR_Client($server, $path = false, $port = 80, $timeout = 15)
{
if (!$path) {
// Assume we have been given a URL instead
$bits = parse_url($server);
$this->server = $bits['host'];
$this->port = isset($bits['port']) ? $bits['port'] : 80;
$this->path = isset($bits['path']) ? $bits['path'] : '/';
// Make absolutely sure we have a path
if (!$this->path) {
$this->path = '/';
}
} else {
$this->server = $server;
$this->path = $path;
$this->port = $port;
}
$this->useragent = 'The Incutio XML-RPC PHP Library';
$this->timeout = $timeout;
}
function query()
{
$args = func_get_args();
$method = array_shift($args);
$request = new IXR_Request($method, $args);
$length = $request->getLength();
$xml = $request->getXml();
$r = "\r\n";
$request = "POST {$this->path} HTTP/1.0$r";
// Merged from WP #8145 - allow custom headers
$this->headers['Host'] = $this->server;
$this->headers['Content-Type'] = 'text/xml';
$this->headers['User-Agent'] = $this->useragent;
$this->headers['Content-Length']= $length;
foreach( $this->headers as $header => $value ) {
$request .= "{$header}: {$value}{$r}";
}
$request .= $r;
$request .= $xml;
// Now send the request
if ($this->debug) {
echo '<pre class="ixr_request">'.htmlspecialchars($request)."\n</pre>\n\n";
}
if ($this->timeout) {
$fp = @fsockopen($this->server, $this->port, $errno, $errstr, $this->timeout);
} else {
$fp = @fsockopen($this->server, $this->port, $errno, $errstr);
}
if (!$fp) {
$this->error = new IXR_Error(-32300, 'transport error - could not open socket');
return false;
}
fputs($fp, $request);
$contents = '';
$debugContents = '';
$gotFirstLine = false;
$gettingHeaders = true;
while (!feof($fp)) {
$line = fgets($fp, 4096);
if (!$gotFirstLine) {
// Check line for '200'
if (strstr($line, '200') === false) {
$this->error = new IXR_Error(-32300, 'transport error - HTTP status code was not 200');
return false;
}
$gotFirstLine = true;
}
if (trim($line) == '') {
$gettingHeaders = false;
}
if (!$gettingHeaders) {
// merged from WP #12559 - remove trim
$contents .= $line;
}
if ($this->debug) {
$debugContents .= $line;
}
}
if ($this->debug) {
echo '<pre class="ixr_response">'.htmlspecialchars($debugContents)."\n</pre>\n\n";
}
// Now parse what we've got back
$this->message = new IXR_Message($contents);
if (!$this->message->parse()) {
// XML error
$this->error = new IXR_Error(-32700, 'parse error. not well formed');
return false;
}
// Is the message a fault?
if ($this->message->messageType == 'fault') {
$this->error = new IXR_Error($this->message->faultCode, $this->message->faultString);
return false;
}
// Message must be OK
return true;
}
function getResponse()
{
// methodResponses can only have one param - return that
return $this->message->params[0];
}
function isError()
{
return (is_object($this->error));
}
function getErrorCode()
{
return $this->error->code;
}
function getErrorMessage()
{
return $this->error->message;
}
}
/**
* IXR_Error
*
* @package IXR
* @since 1.5
*/
class IXR_Error
{
var $code;
var $message;
function IXR_Error($code, $message)
{
$this->code = $code;
$this->message = htmlspecialchars($message);
}
function getXml()
{
$xml = <<<EOD
<methodResponse>
<fault>
<value>
<struct>
<member>
<name>faultCode</name>
<value><int>{$this->code}</int></value>
</member>
<member>
<name>faultString</name>
<value><string>{$this->message}</string></value>
</member>
</struct>
</value>
</fault>
</methodResponse>
EOD;
return $xml;
}
}
/**
* IXR_Date
*
* @package IXR
* @since 1.5
*/
class IXR_Date {
var $year;
var $month;
var $day;
var $hour;
var $minute;
var $second;
var $timezone;
function IXR_Date($time)
{
// $time can be a PHP timestamp or an ISO one
if (is_numeric($time)) {
$this->parseTimestamp($time);
} else {
$this->parseIso($time);
}
}
function parseTimestamp($timestamp)
{
$this->year = date('Y', $timestamp);
$this->month = date('m', $timestamp);
$this->day = date('d', $timestamp);
$this->hour = date('H', $timestamp);
$this->minute = date('i', $timestamp);
$this->second = date('s', $timestamp);
$this->timezone = '';
}
function parseIso($iso)
{
$this->year = substr($iso, 0, 4);
$this->month = substr($iso, 4, 2);
$this->day = substr($iso, 6, 2);
$this->hour = substr($iso, 9, 2);
$this->minute = substr($iso, 12, 2);
$this->second = substr($iso, 15, 2);
$this->timezone = substr($iso, 17);
}
function getIso()
{
return $this->year.$this->month.$this->day.'T'.$this->hour.':'.$this->minute.':'.$this->second.$this->timezone;
}
function getXml()
{
return '<dateTime.iso8601>'.$this->getIso().'</dateTime.iso8601>';
}
function getTimestamp()
{
return mktime($this->hour, $this->minute, $this->second, $this->month, $this->day, $this->year);
}
}
/**
* IXR_Base64
*
* @package IXR
* @since 1.5
*/
class IXR_Base64
{
var $data;
function IXR_Base64($data)
{
$this->data = $data;
}
function getXml()
{
return '<base64>'.base64_encode($this->data).'</base64>';
}
}
/**
* IXR_IntrospectionServer
*
* @package IXR
* @since 1.5
*/
class IXR_IntrospectionServer extends IXR_Server
{
var $signatures;
var $help;
function IXR_IntrospectionServer()
{
$this->setCallbacks();
$this->setCapabilities();
$this->capabilities['introspection'] = array(
'specUrl' => 'http://xmlrpc.usefulinc.com/doc/reserved.html',
'specVersion' => 1
);
$this->addCallback(
'system.methodSignature',
'this:methodSignature',
array('array', 'string'),
'Returns an array describing the return type and required parameters of a method'
);
$this->addCallback(
'system.getCapabilities',
'this:getCapabilities',
array('struct'),
'Returns a struct describing the XML-RPC specifications supported by this server'
);
$this->addCallback(
'system.listMethods',
'this:listMethods',
array('array'),
'Returns an array of available methods on this server'
);
$this->addCallback(
'system.methodHelp',
'this:methodHelp',
array('string', 'string'),
'Returns a documentation string for the specified method'
);
}
function addCallback($method, $callback, $args, $help)
{
$this->callbacks[$method] = $callback;
$this->signatures[$method] = $args;
$this->help[$method] = $help;
}
function call($methodname, $args)
{
// Make sure it's in an array
if ($args && !is_array($args)) {
$args = array($args);
}
// Over-rides default call method, adds signature check
if (!$this->hasMethod($methodname)) {
return new IXR_Error(-32601, 'server error. requested method "'.$this->message->methodName.'" not specified.');
}
$method = $this->callbacks[$methodname];
$signature = $this->signatures[$methodname];
$returnType = array_shift($signature);
// Check the number of arguments
if (count($args) != count($signature)) {
return new IXR_Error(-32602, 'server error. wrong number of method parameters');
}
// Check the argument types
$ok = true;
$argsbackup = $args;
for ($i = 0, $j = count($args); $i < $j; $i++) {
$arg = array_shift($args);
$type = array_shift($signature);
switch ($type) {
case 'int':
case 'i4':
if (is_array($arg) || !is_int($arg)) {
$ok = false;
}
break;
case 'base64':
case 'string':
if (!is_string($arg)) {
$ok = false;
}
break;
case 'boolean':
if ($arg !== false && $arg !== true) {
$ok = false;
}
break;
case 'float':
case 'double':
if (!is_float($arg)) {
$ok = false;
}
break;
case 'date':
case 'dateTime.iso8601':
if (!is_a($arg, 'IXR_Date')) {
$ok = false;
}
break;
}
if (!$ok) {
return new IXR_Error(-32602, 'server error. invalid method parameters');
}
}
// It passed the test - run the "real" method call
return parent::call($methodname, $argsbackup);
}
function methodSignature($method)
{
if (!$this->hasMethod($method)) {
return new IXR_Error(-32601, 'server error. requested method "'.$method.'" not specified.');
}
// We should be returning an array of types
$types = $this->signatures[$method];
$return = array();
foreach ($types as $type) {
switch ($type) {
case 'string':
$return[] = 'string';
break;
case 'int':
case 'i4':
$return[] = 42;
break;
case 'double':
$return[] = 3.1415;
break;
case 'dateTime.iso8601':
$return[] = new IXR_Date(time());
break;
case 'boolean':
$return[] = true;
break;
case 'base64':
$return[] = new IXR_Base64('base64');
break;
case 'array':
$return[] = array('array');
break;
case 'struct':
$return[] = array('struct' => 'struct');
break;
}
}
return $return;
}
function methodHelp($method)
{
return $this->help[$method];
}
}
/**
* IXR_ClientMulticall
*
* @package IXR
* @since 1.5
*/
class IXR_ClientMulticall extends IXR_Client
{
var $calls = array();
function IXR_ClientMulticall($server, $path = false, $port = 80)
{
parent::IXR_Client($server, $path, $port);
$this->useragent = 'The Incutio XML-RPC PHP Library (multicall client)';
}
function addCall()
{
$args = func_get_args();
$methodName = array_shift($args);
$struct = array(
'methodName' => $methodName,
'params' => $args
);
$this->calls[] = $struct;
}
function query()
{
// Prepare multicall, then call the parent::query() method
return parent::query('system.multicall', $this->calls);
}
}