File: xcs.php

<?

/**
 * Exit the script with an error message.
 */
function wrapper_fatal_error($err) {
	header("Status: 404 $err");
	echo $err;
    error_log($err);
	exit();
}

header('Content-Type: text/xml');
// header('Content-Type: text/plain');


// -- locate the class and create class instance ------------------------------

// we must have this variable available
if (isset($HTTP_SERVER_VARS['PATH_INFO']) == false) {
	wrapper_fatal_error('Class and constructor data not available.');
}

// get the name of the class and the initialisers
$init_parameters = explode('/', substr($HTTP_SERVER_VARS['PATH_INFO'], 1));

if (count($init_parameters) < 1) {
	wrapper_fatal_error('Class name not defined.');
}

$class_name = array_shift($init_parameters);

// load the class data
@include_once("./class." . $class_name . ".php");

if (class_exists($class_name) == false) {
	wrapper_fatal_error("Class '$class_name' cannot be found.");
}

// create the object

$x  = '$class_instance = new ' . $class_name . '(';
$i = 0;
foreach($init_parameters as $parameter) {

    if ($i != 0) $x .= ', ';
    $i++;
    
    $x .= "'$parameter'";
}
$x .= ');';

@eval($x);

// have we created an object?
if (isset($class_instance) == false) {
    wrapper_fatal_error("Could not create the object.");
}


// init the object now, but only if the method is
// defined; this will give the object a chance to
// return false if something is wrong
if (method_exists($class_instance, '_init')) {

	// the _init method must verify all parameters
	// and return false if an error is found (say, not enough
	// parameters defined
    $r = @call_user_method_array('_init', $class_instance, $init_parameters);
    if ($r == false) {
		wrapper_fatal_error('Object initialisation failed.');
    }
}



// -- locate or create a request ----------------------------------------------

// is it GET or POST
// if it is GET - use URL variables
// otherwise expect XML-RPC payload

if ($HTTP_SERVER_VARS['REQUEST_METHOD'] == 'GET') {

	// get the method name from the parameter list
	$method_name = strtolower($HTTP_GET_VARS['_method']);

	// construct the XML-RPC payload

	// enumerate GET parameters and transform
	// them into XML

	$request_xml = '<?xml version="1.0"?>';
	$request_xml .= '<methodCall>';
	$request_xml .= '<methodName>';

	// todo: escape $method_name
	$request_xml .= $method_name;
	$request_xml .= '</methodName>';

	$request_xml .= '<params>';

	// params go here
	foreach($HTTP_GET_VARS as $key => $value) {
		// skip over our internal method
		if ($key == '_method') continue;

		// todo: escape parameter values
		$request_xml .= '<param><string>' . $value . '</string></param>';
	}
	
	$request_xml .= '</params>';
	$request_xml .= '</methodCall>';

} else
if ($HTTP_SERVER_VARS['REQUEST_METHOD'] == 'POST') {
    // with a POST method, we always assume XML-RPC payload
	// copy the payload from the raw POST data
	$request_xml = $HTTP_RAW_POST_DATA;

    // todo: lowercase the method name
} else {
    // fatal error, unsupported access method
    wrapper_fatal_error("Unsuported method");
}


// -- actual XML-RPC processing -----------------------------------------------

/**
 * All XML-RPC method calls go through this
 * gateway function.
 */
function xmlrpc_gateway($method_name, $params, $app_data) {
	global $class_instance;

	return call_user_method_array($method_name, $class_instance, $params);
}


// create a server instance
$xmlrpc_server = xmlrpc_server_create();

if($xmlrpc_server == false) {
	// could not create the server
	// todo:
}

// register public class methods
// with the xmlrpc server

$class_methods = get_class_methods($class_name);

foreach($class_methods as $method_name) {

	// ignore private methods
	// private methods are those
	// starting with an underscore
	if (ereg("^_", $method_name)) continue;

	// register the method
	xmlrpc_server_register_method($xmlrpc_server, $method_name, 'xmlrpc_gateway');
}

// execute the method call
$foo = @xmlrpc_server_call_method($xmlrpc_server, $request_xml, '', array(output_type => "xml"));
echo $foo;

// free server resources
xmlrpc_server_destroy($xmlrpc_server);

?>