xmlrpc_server_call_method() with class methods
<?php
require_once ('Connections/adodb_mysql_connection.php');
// Instantiating my own class
$my_report = new external_report($db_connection);
// Setting up the XML-RPC "server"
$xmlrpc_server_handler = xmlrpc_server_create();
xmlrpc_server_register_method($xmlrpc_server_handler, "external_method", array(&$my_report, "export"));
// Creating XML return data
if ($response = xmlrpc_server_call_method($xmlrpc_server_handler, $HTTP_RAW_POST_DATA, null))
    {
header('Content-Type: text/xml');
    echo $response;
    }
// **************** class definition ****************
class external_report
{
    protected $db_connection;
    public function __construct($db_connection_pointer)
        {
        if (method_exists($db_connection_pointer, "Execute")) $this->db_connection = $db_connection_pointer;
        else die("...");
        }
    public function export($method_name, $params_array)
        {
$id_dir = (int)$params_array[0];
$id_usr = (int)$params_array[1]; // not used, just an example
        // We have to add arguments' validating code here and NOT inside the constructor (as usual)
        // because arguments are passed directly by xmlrpc_server_call_method (?!!)
$myexport = array();
$dirs_query = "SELECT documento_id FROM tabella_cartelle WHERE cartella_id = ".$id_dir;
$dirs_result = $this->db_connection->Execute($dirs_query) or die("...");
$index = 0;
        while(!$dirs_result->EOF)
            {
$docs_query = "SELECT codice, titolo FROM tabella_documenti WHERE id_documento = ".$dirs_result->Fields('documento_id');
$docs_result = $this->db_connection->Execute($docs_query) or die("...");
$myexport[$index]['codice'] = $docs_result->Fields('codice');
$myexport[$index]['titolo'] = $docs_result->Fields('titolo');
$index++;
$dirs_result->MoveNext();
            }
        return $myexport;
        }
    }
?>