egroupware/phpgwapi/inc/class.egw.inc.php

<?php
/**
 * eGroupWare API - Applications
 *
 * @link http://www.egroupware.org
 * This file was originaly written by Dan Kuykendall and Joseph Engo
 * Copyright (C) 2000, 2001 Dan Kuykendall
 * Parts Copyright (C) 2003 Free Software Foundation
 * @author	RalfBecker@outdoor-training.de
 * @license http://opensource.org/licenses/gpl-license.php GPL - GNU General Public License
 * @package api
 * @version $Id$
 */

/**
 * New written class to create the eGW enviroment AND restore it from a php-session
 *
 * Rewritten by RalfBecker@outdoor-training.de to store the eGW enviroment
 * (egw-object and egw_info-array) in a php-session and restore it from
 * there instead of creating it completly new on each page-request.
 * The enviroment gets now created by the egw-class
 *
 * Use now a php5 getter method to create the usuall subobject on demand, to allow a quicker
 * header include on sites not useing php4-restore.
 * This also makes a lot of application code, like the following, unnecessary:
 * if (!is_object($GLOBALS['egw']->datetime)
 * {
 * 		$GLOBALS['egw']->datetime = CreateObject('phpgwapi.datetime');
 * }
 * You can now simply use $GLOBALS['egw']->datetime, and the egw class instanciates it for you on demand.
 */
class egw extends egw_minimal
{
	/**
	 * Turn on debug mode. Will output additional data for debugging purposes.
	 * @var	string
	 * @access	public
	 */
	var $debug = 0;		// This will turn on debugging information.
	/**
	 * Instance of the account object
	 *
	 * @var accounts
	 */
	var $accounts;
	/**
	 * Instace of the common object
	 *
	 * @var common
	 */
	var $common;
	/**
	 * Instace of the hooks object
	 *
	 * @var hooks
	 */
	var $hooks;

	/**
	 * Constructor: Instantiates the sub-classes
	 *
	 * @author RalfBecker@outdoor-training.de
	 * @param array $domain_names array with valid egw-domain names
	 */
	function __construct($domain_names=null)
	{
		$GLOBALS['egw'] =& $this;	// we need to be immediately available there for the other classes we instantiate
		// for the migration: reference us to the old phpgw object
		$GLOBALS['phpgw'] =& $this;
		$this->setup($domain_names,True);
	}

	/**
	 * Called every time the constructor is called.  Also called by sessions to ensure the correct db,
	 *  in which case we do not recreate the session object.
	 * @author RalfBecker@outdoor-training.de (moved to setup() by milos@groupwhere.org
	 * @param array $domain_names array with valid egw-domain names
	 * @param boolean $createsessionobject True to create the session object (default=True)
	 */
	function setup($domain_names,$createsessionobject=True)
	{
		// create the DB-object
		$this->db = new egw_db($GLOBALS['egw_info']['server']);
		if ($this->debug)
		{
			$this->db->Debug = 1;
		}
		$this->db->set_app('phpgwapi');

		// check if eGW is already setup, if not redirect to setup/
		try {
			$this->db->connect();
			$num_config = $this->db->select(config::TABLE,'COUNT(config_name)',false,__LINE__,__FILE__)->fetchColumn();
		}
		catch(egw_exception_db_connection $e) {
			// ignore exception, get handled below
		}
		catch(egw_exception_db_invalid_sql $e1) {
			unset($e1);	// not used
			try {
				$phpgw_config = $this->db->select('phpgw_config','COUNT(config_name)',false,__LINE__,__FILE__)->fetchColumn();
			}
			catch (egw_exception_db_invalid_sql $e2) {
				unset($e2);	// not used
				// ignor error, get handled below
			}
		}
		if (!$num_config)
		{
			// we check for the old table too, to not scare updating users ;-)
			if ($phpgw_config)
			{
				throw new Exception('You need to update EGroupware before you can continue using it.',999);
			}
			if ($e)
			{
				throw new egw_exception_db_setup('Connection with '.$e->getMessage()."\n\n".
					'Maybe you not created a database for EGroupware yet.',999);
			}
			throw new egw_exception_db_setup('It appears that you have not created the database tables for EGroupware.',999);
		}
		// Set the DB's client charset if a system-charset is set and some other values needed by egw_cache (used in config::read)
		foreach($this->db->select(config::TABLE,'config_name,config_value',array(
			'config_app'  => 'phpgwapi',
			'config_name' => array('system_charset','install_id','temp_dir'),
		),__LINE__,__FILE__) as $row)
		{
			$GLOBALS['egw_info']['server'][$row['config_name']] = $row['config_value'];
		}
		if ($GLOBALS['egw_info']['server']['system_charset'])
		{
			$this->db->Link_ID->SetCharSet($GLOBALS['egw_info']['server']['system_charset']);
		}
		// load up the $GLOBALS['egw_info']['server'] array
		$GLOBALS['egw_info']['server'] += config::read('phpgwapi');

		// if no server timezone set, use date_default_timezone_get() to determine it once
		// it fills to log with deprecated warnings under 5.3 otherwise
		if (empty($GLOBALS['egw_info']['server']['server_timezone']) ||
			$GLOBALS['egw_info']['server']['server_timezone'] == 'System/Localtime')	// treat invalid tz like empty!
		{
			try
			{
				$tz = new DateTimeZone(date_default_timezone_get());
				config::save_value('server_timezone',$GLOBALS['egw_info']['server']['server_timezone'] = $tz->getName(),'phpgwapi');
				error_log(__METHOD__."() stored server_timezone=".$GLOBALS['egw_info']['server']['server_timezone']);
			}
			catch(Exception $e)
			{
				// do nothing if new DateTimeZone fails (eg. 'System/Localtime' returned), specially do NOT store it!
				error_log(__METHOD__."() NO valid 'date.timezone' set in your php.ini!");
			}
		}
		date_default_timezone_set($GLOBALS['egw_info']['server']['server_timezone']);

		// setup the other subclasses
		// translation class is here only for backward compatibility, as all it's methods can be called static now
		$this->translation    = new translation();
		$this->common         = new common();
		$this->accounts       = accounts::getInstance();
		$this->acl            = new acl();
		// we instanciate the hooks object here manually, to cache it's hooks in the session
		$this->hooks          = new hooks();
		/* Do not create the session object if called by the sessions class.  This way
		 * we ensure the correct db based on the user domain.
		 */
		if($createsessionobject)
		{
			$this->session    = new egw_session($domain_names);
		}
		$this->preferences    = new preferences();
		$this->applications   = new applications();

		if ($GLOBALS['egw_info']['flags']['currentapp'] != 'login' && $GLOBALS['egw_info']['flags']['currentapp'] != 'logout')
		{
			$this->verify_session();
			$this->applications->read_installed_apps();	// to get translated app-titles, has to be after verify_session

			$this->define_egw_constants();

			$this->check_app_rights();

			$this->load_optional_classes();
		}
		else	// set the defines for login, in case it's more then just login
		{
			$this->define_egw_constants();
		}
	}

	/**
	 * __wakeup function gets called by php while unserializing the egw-object, eg. reconnects to the DB
	 *
	 * @author RalfBecker@outdoor-training.de
	 */
	function __wakeup()
	{
		$GLOBALS['egw'] =& $this;	// we need to be immediately available there for the other classes we instantiate
		// for the migration: reference us to the old phpgw object
		$GLOBALS['phpgw'] =& $this;

		if ($GLOBALS['egw_info']['server']['system_charset'])
		{
			$this->db->Link_ID->SetCharSet($GLOBALS['egw_info']['server']['system_charset']);
		}
		// restoring server timezone, to avoid warnings under php5.3
		if (!empty($GLOBALS['egw_info']['server']['server_timezone']))
		{
			date_default_timezone_set($GLOBALS['egw_info']['server']['server_timezone']);
		}

		$this->define_egw_constants();
	}

	/**
	 * wakeup2 function needs to be called after unserializing the egw-object
	 *
	 * It adapts the restored object/enviroment to the changed (current) application / page-request
	 *
	 * @author RalfBecker@outdoor-training.de
	 */
	function wakeup2()
	{
		// do some application specific stuff, need to be done as we are different (current) app now
		if (isset($this->template))
		{
			$this->template->set_root(EGW_APP_TPL);
		}
		// init the translation class, necessary as own wakeup would run before our's
		translation::init(isset($GLOBALS['egw_info']['flags']['load_translations']) ? $GLOBALS['egw_info']['flags']['load_translations'] : true);

		$this->unset_datetime();

		// verify the session
		$GLOBALS['egw']->verify_session();
		$GLOBALS['egw']->check_app_rights();

		$this->load_optional_classes();
	}

	/**
	 * Unsetting datetime object, so time gets updated
	 */
	function unset_datetime()
	{
		unset($this->datetime);
	}

	/**
	 * load optional classes by mentioning them in egw_info[flags][enable_CLASS_class] => true
	 *
	 * Also loads the template-class if not egw_info[flags][disable_Template_class] is set
	 *
	 * Maybe the whole thing should be depricated ;-)
	 */
	function load_optional_classes()
	{
		// output the header unless the developer turned it off
		if (!@$GLOBALS['egw_info']['flags']['noheader'])
		{
			common::egw_header();
		}

		// Load the (depricated) app include files if they exists
		if (EGW_APP_INC != "" && ! preg_match ('/phpgwapi/i', EGW_APP_INC) &&
		file_exists(EGW_APP_INC . '/functions.inc.php') && !isset($_GET['menuaction']))
		{
			include(EGW_APP_INC . '/functions.inc.php');
		}
		if (!@$GLOBALS['egw_info']['flags']['noheader'] && !@$GLOBALS['egw_info']['flags']['noappheader'] &&
		file_exists(EGW_APP_INC . '/header.inc.php') && !isset($_GET['menuaction']))
		{
			include(EGW_APP_INC . '/header.inc.php');
		}
	}

	/**
	 * Verfiy there is a valid session
	 *
	 * One can specify a callback, which gets called if there's no valid session. If the callback returns true, the parameter
	 * containst account-details (in keys login, passwd and passwd_type) to automatic create an (anonymous session)
	 *
	 * It also checks if enforce_ssl is set in the DB and redirects to the https:// version of the site.
	 *
	 * If there is no valid session and none could be automatic created, the function will redirect to login and NOT return
	 */
	function verify_session()
	{
		if($GLOBALS['egw_info']['server']['enforce_ssl'] === 'redirect' && !$_SERVER['HTTPS'])
		{
			Header('Location: https://' . $_SERVER['HTTP_HOST'] . $_SERVER['REQUEST_URI']);
			exit;
		}
		// check if we have a session, if not try to automatic create one
		if ($this->session->verify()) return true;

		$account = null;
		if (($account_callback = $GLOBALS['egw_info']['flags']['autocreate_session_callback']) && is_callable($account_callback) &&
			($sessionid = call_user_func_array($account_callback,array(&$account))) === true)	// $account_call_back returns true, false or a session-id
		{
			$sessionid = $this->session->create($account);
		}
		if (!$sessionid)
		{
			//echo "<p>account_callback='$account_callback', account=".print_r($account,true).", sessionid=$sessionid</p>\n"; exit;
			// we forward to the same place after the re-login
			if ($GLOBALS['egw_info']['server']['webserver_url'] && $GLOBALS['egw_info']['server']['webserver_url'] != '/' &&
				($webserver_path = parse_url($GLOBALS['egw_info']['server']['webserver_url'],PHP_URL_PATH)) && $webserver_path != '/')
			{
				// we have to use only path component, to cope with domains like http://egroupware.domain.com and /egroupware
				list(,$relpath) = explode($webserver_path,parse_url($_SERVER['PHP_SELF'],PHP_URL_PATH),2);
			}
			else	// the webserver-url is empty or just a slash '/' (eGW is installed in the docroot and no domain given)
			{
				$matches = null;
				if (preg_match('/^https?:\/\/[^\/]*\/(.*)$/',$relpath=$_SERVER['PHP_SELF'],$matches))
				{
					$relpath = $matches[1];
				}
			}
			// this removes the sessiondata if its saved in the URL
			$query = preg_replace('/[&]?sessionid(=|%3D)[^&]+&kp3(=|%3D)[^&]+&domain=.*$/','',$_SERVER['QUERY_STRING']);
			if ($GLOBALS['egw_info']['server']['http_auth_types'])
			{
				$redirect = '/phpgwapi/ntlm/index.php?';
			}
			else
			{
				$redirect = '/login.php?';
				// only add "your session could not be verified", if a sessionid is given (cookie or on url)
				if (egw_session::get_sessionid()) $redirect .= 'cd=10&';
			}
			if ($relpath) $redirect .= 'phpgw_forward='.urlencode($relpath.(!empty($query) ? '?'.$query : ''));
			//Header('Location: '.$GLOBALS['egw_info']['server']['webserver_url'].$redirect);
			// do NOT redirect, but set top.location, as this works in framed template too
			$redirect = $GLOBALS['egw_info']['server']['webserver_url'].$redirect;

			echo "<html>\n<head>\n<script type='text/javascript'>top.location='$redirect';</script>\n</head>\n";
			exit;
		}
	}

	/**
	 * Verify the user has rights for the requested app
	 *
	 * If the user has no rights for the app (eg. called via URL) he get a permission denied page (this function does NOT return)
	 */
	function check_app_rights()
	{
		$this->currentapp = $GLOBALS['egw_info']['flags']['currentapp'];	// some apps change it later

		if ($GLOBALS['egw_info']['flags']['currentapp'] != 'home')	// give everyone implicit home rights
		{
			// This will need to use ACL in the future
			if (!$GLOBALS['egw_info']['user']['apps'][$currentapp = $GLOBALS['egw_info']['flags']['currentapp']] ||
				($GLOBALS['egw_info']['flags']['admin_only'] && !$GLOBALS['egw_info']['user']['apps']['admin']))
			{
				// present a login page, if anon user has no right for an application
				if ($this->session->session_flags == 'A')
				{
					egw::redirect_link('/logout.php');
				}
				if ($currentapp == 'admin' || $GLOBALS['egw_info']['flags']['admin_only'])
				{
					throw new egw_exception_no_permission_admin();
				}
				throw new egw_exception_no_permission_app($currentapp);
			}
		}
	}

	/**
	 * create all the defines / constants of the eGW-environment (plus the deprecated phpgw ones)
	 */
	function define_egw_constants()
	{
		define('SEP',filesystem_separator());
		define('EGW_ACL_READ',1);
		define('EGW_ACL_ADD',2);
		define('EGW_ACL_EDIT',4);
		define('EGW_ACL_DELETE',8);
		define('EGW_ACL_PRIVATE',16);
		define('EGW_ACL_GROUP_MANAGERS',32);
		define('EGW_ACL_CUSTOM_1',64);
		define('EGW_ACL_CUSTOM_2',128);
		define('EGW_ACL_CUSTOM_3',256);
		// and the old ones
		define('PHPGW_ACL_READ',1);
		define('PHPGW_ACL_ADD',2);
		define('PHPGW_ACL_EDIT',4);
		define('PHPGW_ACL_DELETE',8);
		define('PHPGW_ACL_PRIVATE',16);
		define('PHPGW_ACL_GROUP_MANAGERS',32);
		define('PHPGW_ACL_CUSTOM_1',64);
		define('PHPGW_ACL_CUSTOM_2',128);
		define('PHPGW_ACL_CUSTOM_3',256);
		// A few hacker resistant constants that will be used throught the program
		define('EGW_TEMPLATE_DIR', $this->common->get_tpl_dir('phpgwapi'));
		define('EGW_IMAGES_DIR', $this->common->get_image_path('phpgwapi'));
		define('EGW_IMAGES_FILEDIR', $this->common->get_image_dir('phpgwapi'));
		define('EGW_APP_ROOT', $this->common->get_app_dir());
		define('EGW_APP_INC', $this->common->get_inc_dir());
		define('EGW_APP_TPL', $this->common->get_tpl_dir());
		define('EGW_IMAGES', $this->common->get_image_path());
		define('EGW_APP_IMAGES_DIR', $this->common->get_image_dir());
		// and the old ones
		define('PHPGW_TEMPLATE_DIR',EGW_TEMPLATE_DIR);
		define('PHPGW_IMAGES_DIR',EGW_IMAGES_DIR);
		define('PHPGW_IMAGES_FILEDIR',EGW_IMAGES_FILEDIR);
		define('PHPGW_APP_ROOT',EGW_APP_ROOT);
		define('PHPGW_APP_INC',EGW_APP_INC);
		define('PHPGW_APP_TPL',EGW_APP_TPL);
		define('PHPGW_IMAGES',EGW_IMAGES);
		define('PHPGW_APP_IMAGES_DIR',EGW_APP_IMAGES_DIR);
	}

	/**
	 * force the session cache to be re-created, because some of it's data changed
	 *
	 * Needs to be called if user-preferences, system-config or enabled apps of the current user have been changed and
	 * the change should have immediate effect
	 */
	static function invalidate_session_cache()
	{
		unset($_SESSION['egw_info_cache']);
		unset($_SESSION['egw_object_cache']);
	}

	/**
	 * run string through htmlspecialchars and stripslashes
	 *
	 * @param string $s
	 * @return string The string with html special characters replaced with entities
	 */
	static function strip_html($s)
	{
		return htmlspecialchars(stripslashes($s));
	}

	/**
	 * Link url generator
	 *
	 * @param string	$string	The url the link is for
	 * @param string|array	$extravars=''	Extra params to be passed to the url
	 * @param string $link_app=null if appname or true, some templates generate a special link-handler url
	 * @return string	The full url after processing
	 */
	static function link($url, $extravars = '', $link_app=null)
	{
		return $GLOBALS['egw']->framework->link($url, $extravars, $link_app);
	}

	/**
	 * Redirects direct to a generated link
	 *
	 * @param string	$string	The url the link is for
	 * @param string/array	$extravars	Extra params to be passed to the url
	 * @param string $link_app=null if appname or true, some templates generate a special link-handler url
	 * @return string	The full url after processing
	 */
	static function redirect_link($url, $extravars='', $link_app=null)
	{
		return $GLOBALS['egw']->framework->redirect_link($url, $extravars, $link_app);
	}

	/**
	 * Handles redirects under iis and apache, it does NOT return (calls exit)
	 *
	 * This function handles redirects under iis and apache it assumes that $phpgw->link() has already been called
	 *
	 * @param  string The url ro redirect to
	 * @param string $link_app=null appname to redirect for, default currentapp
	 */
	static function redirect($url, $link_app)
	{
		// Determines whether the current output buffer should be flushed
		$do_flush = true;

		if (egw_json_response::isJSONResponse() || egw_json_request::isJSONRequest())
		{
			$response = egw_json_response::get();
			$response->redirect($url, false, $link_app);

			// If we are in a json request, we should not flush the current output!
			$do_flush = false;
		}
		else
		{
			$file = $line = null;
			if (headers_sent($file,$line))
			{
				throw new egw_exception_assertion_failed(__METHOD__."('".htmlspecialchars($url)."') can NOT redirect, output already started at $file line $line!");
			}
			if ($GLOBALS['egw']->framework instanceof jdots_framework && !empty($link_app))
			{
				egw_framework::set_extra('egw', 'redirect', array($url, $link_app));
				$GLOBALS['egw']->framework->render('');
			}
			else
			{
				Header("Location: $url");
				print("\n\n");
			}
		}

		if ($do_flush)
		{
			@ob_flush(); flush();
		}

		// commit session (if existing), to fix timing problems sometimes preventing session creation ("Your session can not be verified")
		if (isset($GLOBALS['egw']->session)) $GLOBALS['egw']->session->commit_session();

		exit;
	}

	/**
	 * Shortcut to translation class
	 *
	 * This function is a basic wrapper to translation::translate()
	 *
	 * @deprecated only used in the old timetracker
	 * @param  string	The key for the phrase
	 * @see	translation::translate()
	 */
	static function lang($key,$args=null)
	{
		if (!is_array($args))
		{
			$args = func_get_args();
			array_shift($args);
		}
		return translation::translate($key,$args);
	}

	/**
	 * registered shutdown callbacks and optional arguments
	 *
	 * @var array
	 */
	private static $shutdown_callbacks = array();

	/**
	 * Register a callback to run on shutdown AFTER output send to user
	 *
	 * Allows eg. static classes (no destructor) to run on shutdown AND
	 * garanties to run AFTER output send to user.
	 *
	 * @param callable $callback use array($classname, $method) for static methods
	 * @param array $args=array()
	 */
	public static function on_shutdown($callback, array $args=array())
	{
		array_unshift($args, $callback);

		// prepend new callback, to run them in oposite order they are registered
		array_unshift(self::$shutdown_callbacks, $args);
	}

	/**
	 * Shutdown handler running all registered on_shutdown callbacks and then disconnecting from db
	 */
	function __destruct()
	{
		if (!defined('EGW_SHUTDOWN'))
		{
			define('EGW_SHUTDOWN',True);

			// send json response BEFORE flushing output
			if (egw_json_request::isJSONRequest())
			{
				egw_json_response::sendResult();
			}

			// flush all output to user
			/* does NOT work on Apache :-(
			for($i = 0; ob_get_level() && $i < 10; ++$i)
			{
				ob_end_flush();
			}
			flush();*/
			// working for fastCGI :-)
			if (function_exists('fastcgi_finish_request'))
			{
				fastcgi_finish_request();
			}

			// run all on_shutdown, do NOT stop on exceptions
			foreach(self::$shutdown_callbacks as $data)
			{
				try {
					//error_log(__METHOD__."() running ".array2string($data));
					$callback = array_shift($data);
					call_user_func_array($callback, $data);
				}
				catch (Exception $ex) {
					_egw_log_exception($ex);
				}
			}
			// call the asyncservice check_run function if it is not explicitly set to cron-only
			if (!$GLOBALS['egw_info']['server']['asyncservice'])	// is default
			{
				ExecMethod('phpgwapi.asyncservice.check_run','fallback');
			}
			$this->db->disconnect();
		}
	}
}

/**
 * Minimal eGW object used in setup, does not instanciate anything by default
 *
 */
class egw_minimal
{
	/**
	 * Instance of the db-object
	 *
	 * @var egw_db
	 */
	var $db;
	/**
	 * Current app at the instancation of the class
	 *
	 * @var string
	 */
	var $currentapp;
	/**
	 * Global ADOdb object, need to be defined here, to not call magic __get method
	 *
	 * @var ADOConnection
	 */
	var $ADOdb;

	/**
	 * Classes which get instanciated in a different name
	 *
	 * @var array
	 */
	static $sub_objects = array(
		'log' => 'errorlog',
//		'js'  => 'javascript',
		'link' => 'bolink',		// depricated use static egw_link methods
		'datetime' => 'egw_datetime',
//		'session' => 'sessions',
		'session' => 'egw_session',
		'framework' => true,	// special handling in __get()
		'template' => 'Template',
	);

	/**
	 * Magic function to check if a sub-object is set
	 *
	 * @param string $name
	 * @return boolean
	 */
	function __isset($name)
	{
		//error_log(__METHOD__."($name)");
		return isset($this->$name);
	}

	/**
	 * Magic function to return a sub-object
	 *
	 * @param string $name
	 * @return mixed
	 */
	function __get($name)
	{
		//error_log(__METHOD__."($name)".function_backtrace());

		if ($name == 'js') $name = 'framework';	// javascript class is integrated now into framework

		if (isset($this->$name))
		{
			return $this->$name;
		}

		if (!isset(self::$sub_objects[$name]) && !class_exists($name))
		{
			if ($name != 'ADOdb') error_log(__METHOD__.": There's NO $name object! ".function_backtrace());
			return null;
		}
		switch($name)
		{
			case 'framework':
				// default to idots, if no template_set set, to eg. not stall installations if settings use egw::link
				if (empty($GLOBALS['egw_info']['server']['template_set'])) $GLOBALS['egw_info']['server']['template_set'] = 'idots';
				// setup the new eGW framework (template sets)
				$class = $GLOBALS['egw_info']['server']['template_set'].'_framework';
				if (!class_exists($class))	// first try to autoload the class
				{
					require_once($file=EGW_INCLUDE_ROOT.'/phpgwapi/templates/'.$GLOBALS['egw_info']['server']['template_set'].'/class.'.$class.'.inc.php');
					if (!in_array($file,(array)$_SESSION['egw_required_files']))
					{
						$_SESSION['egw_required_files'][] = $file;	// automatic load the used framework class, when the object get's restored
					}
				}
				// fall back to idots if a template does NOT support current user-agent
				if ($class != 'idots_framework' && method_exists($class,'is_supported_user_agent') &&
					!call_user_func(array($class,'is_supported_user_agent')))
				{
					$GLOBALS['egw_info']['server']['template_set'] = 'idots';
					return $this->__get('framework');
				}
				break;
			case 'template':	// need to be instancated for the current app
				if (!($tpl_dir = common::get_tpl_dir($this->currentapp)))
				{
					return null;
				}
				return $this->template = new Template($tpl_dir);
			default:
				$class = isset(self::$sub_objects[$name]) ? self::$sub_objects[$name] : $name;
				break;
		}
		return $this->$name = new $class();
	}
}