* iPhone and Mac Addressbook support aka Apple CalDAV/CardDAV autodetection

Addressbook does NOT allow to specify the URL, unlike iCal which allows it after autodetection fails.
This, some XML specifics set now for Apple addressbook user-agents and etags for addressbook collection itself
allow now to use EGroupware with iPhone or Mac addressbook. The later was working before, if you edited the URL
into a decompiled plist file, but failed now because of a new REPORT it tries on the principal, to find out shared
addessbooks, which we not yet support, but failed to tell in the correct way (501 Not Implemented).
Addressbook sync now the personal addressbook, because that is what we tell it as addressbook-home-set.
We should add some configuration so user can choose what addressbook to set as addressbook-home-set, or to set
the "all" addressbook (/addressbook). For the later we could add some prefs like SyncML to specify filters or
eg. a distribution list.

addressbook/inc/class.addressbook_groupdav.inc.php

@@ -458,9 +458,8 @@ class addressbook_groupdav extends groupdav_handler
 	static function extra_properties(array $props=array(), $displayname, $base_uri=null)
 	{
 		// addressbook description
-		$displayname = $GLOBALS['egw']->translation->convert(lang('Addressbook of') . ' ' .
-			$displayname,
-			$GLOBALS['egw']->translation->charset(),'utf-8');
+		$displayname = translation::convert(lang('Addressbook of') . ' ' .
+			$displayname,translation::charset(),'utf-8');
 		$props[] = HTTP_WebDAV_Server::mkprop(groupdav::CARDDAV,'addressbook-description',$displayname);
 		// supported reports (required property for CardDAV)
 		$props[] =	HTTP_WebDAV_Server::mkprop('supported-report-set',array(

egw-pear/HTTP/WebDAV/Server.php

@@ -639,7 +639,7 @@ class HTTP_WebDAV_Server
                 return;
             }
         }
-
+        
         // now we generate the reply header ...
 		if ($retval === true)
 		{
@@ -676,7 +676,7 @@ class HTTP_WebDAV_Server
 
         // ... and payload
         echo "<?xml version=\"1.0\" encoding=\"utf-8\"?>\n";
-        echo ($this->crrnd?'<':'<D:')."multistatus xmlns:D=\"DAV:\">\n";
+        echo $this->crrnd ? "<multistatus xmlns=\"DAV:\">\n" : "<D:multistatus xmlns:D=\"DAV:\">\n";
 
         // using an ArrayIterator to prevent foreach from copying the array,
         // as we cant loop by reference, when an iterator is given in $files['files']

groupdav.htaccess

@@ -0,0 +1,28 @@
+# EGroupware CalDav or CardDAV support
+#
+# $Id$
+#
+# This file can be copyied as .htaccess to your document root
+# to support Mac or iPhone clients to autodetec CalDAV and CardDAV
+# (currently Addressbook does NOT allow to specify our groupdav.php 
+#  URL manually).
+#
+# As alternative an EGroupware install directly in the docroot or
+# an unconditional redirect from the docroot to EGroupware's index.php 
+# will archive the same thing, as it redirects PROPFIND or OPTION 
+# requests to groupdav.php/ (many have such a redirect already in place).
+#
+# An other alternativ is to copy the PROPFIND/OPTION redirect from
+# the top of EGroupware's index.php into your index.php in the docroot.
+#
+# Please note: 
+# - your Apache web server needs to be setup to read .htaccess files and 
+#   allow use of the RewriteEngine directive (AllowOverride FileInfo). 
+# - you need to replace /egroupware with your EGroupware URL path eg. /egw
+
+RewriteEngine On
+RewriteBase /
+
+RewriteRule ^.well-known/(caldav|carddav)$ /egroupware/groupdav.php/ [R]
+RewriteCond %{REQUEST_METHOD}	^PROPFIND$
+RewriteRule ^/$ /egroupware/groupdav.php/

groupdav.php

@@ -0,0 +1,57 @@
+<?php
+/**
+ * eGroupWare - GroupDAV access
+ *
+ * Using the PEAR HTTP/WebDAV/Server class (which need to be installed!)
+ *
+ * @link http://www.egroupware.org
+ * @license http://opensource.org/licenses/gpl-license.php GPL - GNU General Public License
+ * @package api
+ * @subpackage groupdav
+ * @author Ralf Becker <RalfBecker-AT-outdoor-training.de>
+ * @copyright (c) 2007-9 by Ralf Becker <RalfBecker-AT-outdoor-training.de>
+ * @version $Id$
+ */
+
+$starttime = microtime(true);
+
+/**
+ * check if the given user has access
+ *
+ * Create a session or if the user has no account return authenticate header and 401 Unauthorized
+ *
+ * @param array &$account
+ * @return int session-id
+ */
+function check_access(&$account)
+{
+	if (!isset($_SERVER['PHP_AUTH_USER']) ||
+		!($sessionid = $GLOBALS['egw']->session->create($_SERVER['PHP_AUTH_USER'],$_SERVER['PHP_AUTH_PW'],'text')))
+	{
+		header('WWW-Authenticate: Basic realm="'.groupdav::REALM.
+			// if the session class gives a reason why the login failed --> append it to the REALM
+			($GLOBALS['egw']->session->reason ? ': '.$GLOBALS['egw']->session->reason : '').'"');
+		header('HTTP/1.1 401 Unauthorized');
+		header('X-WebDAV-Status: 401 Unauthorized', true);
+		echo "<html>\n<head>\n<title>401 Unauthorized</title>\n<body>\nAuthorization failed.\n</body>\n</html>\n";
+		exit;
+	}
+	return $sessionid;
+}
+
+$GLOBALS['egw_info']['flags'] = array(
+	'noheader'  => True,
+	'currentapp' => 'groupdav',
+	'autocreate_session_callback' => 'check_access',
+	'no_exception_handler' => 'basic_auth',	// we use a basic auth exception handler (sends exception message as basic auth realm)
+);
+// if you move this file somewhere else, you need to adapt the path to the header!
+$egw_dir = dirname(__FILE__);
+require_once($egw_dir.'/phpgwapi/inc/class.egw_digest_auth.inc.php');
+include($egw_dir.'/header.inc.php');
+
+$headertime = microtime(true);
+
+$groupdav = new groupdav();
+$groupdav->ServeRequest();
+//error_log(sprintf("GroupDAV %s request took %5.3f s (header include took %5.3f s)",$_SERVER['REQUEST_METHOD'],microtime(true)-$starttime,$headertime-$starttime));

index.php

@@ -0,0 +1,180 @@
+<?php
+/**************************************************************************\
+* eGroupWare                                                               *
+* http://www.egroupware.org                                                *
+* --------------------------------------------                             *
+*  This program is free software; you can redistribute it and/or modify it *
+*  under the terms of the GNU General Public License as published by the   *
+*  Free Software Foundation; either version 2 of the License, or (at your  *
+*  option) any later version.                                              *
+\**************************************************************************/
+
+/* $Id$ */
+
+// support of Mac or iPhone trying to autodetect CalDAV or CardDAV support
+// if EGroupware is not installed in the docroot, you need either this code in the index.php there,
+// or an uncoditional redirect to this file or copy groupdav.htaccess to your docroot as .htaccess
+if ($_SERVER['REQUEST_METHOD'] == 'PROPFIND' || $_SERVER['REQUEST_METHOD'] == 'OPTIONS')
+{
+        header('Location: groupdav.php/');
+        exit;
+}
+
+// forward for not existing or empty header to setup
+if(!file_exists('header.inc.php') || !filesize('header.inc.php'))
+{
+	Header('Location: setup/index.php');
+	exit;
+}
+
+if(isset($_GET['hasupdates']) && $_GET['hasupdates'] == 'yes')
+{
+	$hasupdates = True;
+}
+
+/*
+	This is the menuaction driver for the multi-layered design
+*/
+if(isset($_GET['menuaction']) && preg_match('/^[A-Za-z0-9_]+\.[A-Za-z0-9_]+\.[A-Za-z0-9_]+$/',$_GET['menuaction']))
+{
+	list($app,$class,$method) = explode('.',$_GET['menuaction']);
+	if(! $app || ! $class || ! $method)
+	{
+		$invalid_data = True;
+	}
+}
+else
+{
+	$app = 'home';
+	$invalid_data = True;
+}
+
+if($app == 'phpgwapi')
+{
+	$app = 'home';
+	$api_requested = True;
+}
+
+$GLOBALS['egw_info'] = array(
+	'flags' => array(
+		'noheader'   => True,
+		'nonavbar'   => True,
+		'currentapp' => $app
+	)
+);
+include('./header.inc.php');
+
+// user changed timezone
+if (isset($_GET['tz']))
+{
+	egw_time::setUserPrefs($_GET['tz']);	// throws exception, if tz is invalid
+
+	$GLOBALS['egw']->preferences->add('common','tz',$_GET['tz']);
+	$GLOBALS['egw']->preferences->save_repository();
+
+	if (($referer = common::get_referer()))
+	{
+		egw::redirect_link($referer);
+	}
+}
+
+// 	Check if we are using windows or normal webpage
+$windowed = false;
+$tpl_info = EGW_SERVER_ROOT . '/phpgwapi/templates/' . basename($GLOBALS['egw_info']['user']['preferences']['common']['template_set']) . '/setup/setup.inc.php';
+
+if(@file_exists($tpl_info))
+{
+   include_once($tpl_info);
+//	   if(isset($template_info))
+//	   {
+	  if($GLOBALS['egw_info']['template'][$GLOBALS['egw_info']['user']['preferences']['common']['template_set']]['windowed'])
+	  {
+		 $windowed = true;
+	  }
+//	   }
+}
+
+if($app == 'home' && !$api_requested && !$windowed)
+{
+	if ($GLOBALS['egw_info']['server']['force_default_app'] && $GLOBALS['egw_info']['server']['force_default_app'] != 'user_choice')
+	{
+		$GLOBALS['egw_info']['user']['preferences']['common']['default_app'] = $GLOBALS['egw_info']['server']['force_default_app'];
+	}
+	if($GLOBALS['egw_info']['user']['preferences']['common']['default_app'] && !$hasupdates)
+	{
+		$GLOBALS['egw']->redirect(egw_framework::index($GLOBALS['egw_info']['user']['preferences']['common']['default_app']));
+	}
+	else
+	{
+	   $GLOBALS['egw']->redirect_link('/home/index.php');
+	}
+ }
+
+if($windowed && $_GET['cd'] == 'yes')
+{
+	$GLOBALS['egw_info']['flags'] = array(
+		'noheader'   => False,
+		'nonavbar'   => False,
+		'currentapp' => 'eGroupWare'
+	);
+	$GLOBALS['egw']->common->egw_header();
+	$GLOBALS['egw']->common->egw_footer();
+
+}
+else
+{
+	if($api_requested)
+	{
+		$app = 'phpgwapi';
+	}
+
+	$obj = CreateObject($app.'.'.$class);
+	if((is_array($obj->public_functions) && $obj->public_functions[$method]) && !$invalid_data)
+	{
+		$obj->$method();
+		unset($app);
+		unset($class);
+		unset($method);
+		unset($invalid_data);
+		unset($api_requested);
+	}
+	else
+	{
+		if(!$app || !$class || !$method || $invalid_data)
+		{
+			if(@is_object($GLOBALS['egw']->log))
+			{
+				$GLOBALS['egw']->log->message(array(
+					'text' => 'W-BadmenuactionVariable, menuaction missing or corrupt: %1',
+					'p1'   => $menuaction,
+					'line' => __LINE__,
+					'file' => __FILE__
+				));
+			}
+		}
+
+		if(!is_array($GLOBALS[$class]->public_functions) || !$GLOBALS[$class]->public_functions[$method] && $method)
+		{
+			if(@is_object($GLOBALS['egw']->log))
+			{
+				$GLOBALS['egw']->log->message(array(
+					'text' => 'W-BadmenuactionVariable, attempted to access private method: %1',
+					'p1'   => $method,
+					'line' => __LINE__,
+					'file' => __FILE__
+				));
+			}
+		}
+		if(@is_object($GLOBALS['egw']->log))
+		{
+			$GLOBALS['egw']->log->commit();
+		}
+
+		$GLOBALS['egw']->redirect_link('/home/index.php');
+	}
+
+	if(!isset($GLOBALS['egw_info']['nofooter']))
+	{
+		$GLOBALS['egw']->common->egw_footer();
+	}
+}

infolog/inc/class.infolog_groupdav.inc.php

@@ -550,9 +550,8 @@ class infolog_groupdav extends groupdav_handler
 	static function extra_properties(array $props=array(), $displayname, $base_uri=null)
 	{
 		// calendar description
-		$displayname = $GLOBALS['egw']->translation->convert(lang('Tasks of') . ' ' .
-			$displayname,
-			$GLOBALS['egw']->translation->charset(),'utf-8');
+		$displayname = translation::convert(lang('Tasks of') . ' ' .
+			$displayname,translation::charset(),'utf-8');
 		$props[] = HTTP_WebDAV_Server::mkprop(groupdav::CALDAV,'calendar-description',$displayname);
 		// email of the current user, see caldav-sheduling draft
 		$props[] =	HTTP_WebDAV_Server::mkprop(groupdav::CALDAV,'calendar-user-address-set',array(

phpgwapi/inc/class.groupdav.inc.php

@@ -97,12 +97,6 @@ class groupdav extends HTTP_WebDAV_Server
 	 * @var string
 	 */
 	var $egw_charset;
-	/**
-	 * Reference to the translation class
-	 *
-	 * @var translation
-	 */
-	var $translation;
 	/**
 	 * Instance of our application specific handler
 	 *
@@ -133,6 +127,11 @@ class groupdav extends HTTP_WebDAV_Server
 			case 'kde':	// KAddressbook (at least in 3.5 can NOT subscribe / does NOT find addressbook)
 				$this->client_require_href_as_url = true;
 				break;
+			case 'cfnetwork':	// Apple addressbook app
+			case 'dataaccess':	// iPhone addressbook
+				$this->client_require_href_as_url = false;
+				$this->cnrnd = true;
+				break;
 			case 'davkit':	// iCal app in OS X 10.6 created wrong request, if full url given
 				$this->client_require_href_as_url = false;
 				break;
@@ -144,8 +143,7 @@ class groupdav extends HTTP_WebDAV_Server
 		}
 		parent::HTTP_WebDAV_Server();
 
-		$this->translation =& $GLOBALS['egw']->translation;
-		$this->egw_charset = $this->translation->charset();
+		$this->egw_charset = translation::charset();
 		if (strpos($this->base_uri, 'http') === 0)
 		{
 			$this->principalURL = $this->_slashify($this->base_uri);
@@ -156,6 +154,12 @@ class groupdav extends HTTP_WebDAV_Server
 				'//' . $_SERVER['HTTP_HOST'] . $_SERVER['SCRIPT_NAME'] . '/';
 		}
 		$this->principalURL .= 'principals/users/'.$GLOBALS['egw_info']['user']['account_lid'].'/';
+		
+		// if client requires pathes instead of URLs
+		if ($this->client_require_href_as_url === false)
+		{
+			$this->principalURL = parse_url($this->principalURL,PHP_URL_PATH);
+		}
 		$this->accounts = $GLOBALS['egw']->accounts;
 	}
 
@@ -183,7 +187,7 @@ class groupdav extends HTTP_WebDAV_Server
 		switch($app)
 		{
 			case 'calendar':
-				$dav[] = 2;
+				if (!in_array(2,$dav)) $dav[] = 2;
 				$dav[] = 'access-control';
 				$dav[] = 'calendar-access';
 				//$dav[] = 'calendar-schedule';
@@ -192,15 +196,16 @@ class groupdav extends HTTP_WebDAV_Server
 				//$dav[] = 'calendarserver-private-events';
 				break;
 			case 'addressbook':
-				$dav[] = 2;
-				$dav[] = 3;
+				if (!in_array(2,$dav)) $dav[] = 2;
+				//$dav[] = 3;	// revision aka versioning support not implemented
 				$dav[] = 'access-control';
-				$dav[] = 'addressbook-access';
+				$dav[] = 'addressbook';	// CardDAV uses "addressbook" NOT "addressbook-access"
 				break;
 			default:
-				$dav[] = 2;
+				if (!in_array(2,$dav)) $dav[] = 2;
 				$dav[] = 'access-control';
 				$dav[] = 'calendar-access';
+				$dav[] = 'addressbook';
 		}
 		// not yet implemented: $dav[] = 'access-control';
 	}
@@ -291,7 +296,7 @@ class groupdav extends HTTP_WebDAV_Server
 					// OUTBOX URLs of the current user
 					self::mkprop(groupdav::CALDAV,'schedule-outbox-URL',array(
 						self::mkprop(groupdav::DAV,'href',$this->base_uri.'/calendar/'))),
-				);
+			);
 			//$props = self::current_user_privilege_set($props);
 			$files['files'][] = array(
 				'path'  => $path,
@@ -326,6 +331,7 @@ class groupdav extends HTTP_WebDAV_Server
 						$props[] = self::mkprop(
 							groupdav::CALENDARSERVER,'getctag',$handler->getctag($options['path'],$user));
 					}
+					$props[] = self::mkprop('getetag','EGw-'.$app.'-wGE');
 					$files['files'][] = array(
 		            	'path'  => $path.$app.'/',
 		            	'props' => $props,
@@ -349,7 +355,7 @@ class groupdav extends HTTP_WebDAV_Server
 		        	'props' => $this->_properties($app,$app=='addressbook'&&strpos($_SERVER['HTTP_USER_AGENT'],'KHTML') !== false,$user,$path),
 		        );
 			}
-			if (isset($options['depth']) && !$options['depth'] && !$id)
+			if ($method != 'REPORT' && isset($options['depth']) && !$options['depth'] && !$id)
 			{
 				// add ctag if handler implements it (only for depth 0)
 				if (method_exists($handler,'getctag'))
@@ -412,7 +418,8 @@ class groupdav extends HTTP_WebDAV_Server
 				self::mkprop('href',$this->base_uri.'/principals/'.$principalType.'/'.$GLOBALS['egw_info']['user']['account_lid'].'/'),
 				self::mkprop('href','urn:uuid:'.$GLOBALS['egw_info']['user']['account_lid']))),
 			self::mkprop(groupdav::CALENDARSERVER,'email-address-set',array(
-				self::mkprop(groupdav::CALENDARSERVER,'email-address',$GLOBALS['egw_info']['user']['email']))),		
+				self::mkprop(groupdav::CALENDARSERVER,'email-address',$GLOBALS['egw_info']['user']['email']))),
+			self::mkprop('getetag','EGw-no-etag-wGE'),	// iPhone addressbook requires an etag here!		
 		);
 
 		switch ($app)
@@ -427,13 +434,13 @@ class groupdav extends HTTP_WebDAV_Server
 			case 'infolog':
 				$props[] = self::mkprop(groupdav::CALDAV,'calendar-home-set',array(
 					self::mkprop('href',$this->base_uri.$path.'infolog/')));
-				$displayname = $this->translation->convert(lang($app).' '.
+				$displayname = translation::convert(lang($app).' '.
 					common::grab_owner_name($user),$this->egw_charset,'utf-8');
 				break;
 			default:
 				$props[] = self::mkprop(groupdav::CALDAV,'calendar-home-set',array(
 					self::mkprop('href',$this->base_uri.$path)));
-				$displayname = $this->translation->convert(lang($app).' '.
+				$displayname = translation::convert(lang($app).' '.
 				common::grab_owner_name($user),$this->egw_charset,'utf-8');
 		}
 		$props[] = self::mkprop(groupdav::CARDDAV,'addressbook-home-set',array(

phpgwapi/inc/class.groupdav_handler.inc.php

@@ -0,0 +1,541 @@
+<?php
+/**
+ * EGroupware: GroupDAV access: abstract baseclass for groupdav/caldav/carddav handlers
+ *
+ * @link http://www.egroupware.org
+ * @license http://opensource.org/licenses/gpl-license.php GPL - GNU General Public License
+ * @package api
+ * @subpackage groupdav
+ * @author Ralf Becker <RalfBecker-AT-outdoor-training.de>
+ * @copyright (c) 2007-9 by Ralf Becker <RalfBecker-AT-outdoor-training.de>
+ * @version $Id$
+ */
+
+/**
+ * EGroupware: GroupDAV access: abstract baseclass for groupdav/caldav/carddav handlers
+ */
+abstract class groupdav_handler
+{
+	/**
+	 * Debug level: 0 = nothing, 1 = function calls, 2 = more info, eg. complete $_SERVER array
+	 *
+	 * The debug messages are send to the apache error_log
+	 *
+	 * @var integer
+	 */
+	var $debug = 0;
+
+	/**
+	 * eGW's charset
+	 *
+	 * @var string
+	 */
+	var $egw_charset;
+	/**
+	 * Reference to the accounts class
+	 *
+	 * @var accounts
+	 */
+	var $accounts;
+	/**
+	 * Translates method names into ACL bits
+	 *
+	 * @var array
+	 */
+	var $method2acl = array(
+		'GET' => EGW_ACL_READ,
+		'PUT' => EGW_ACL_EDIT,
+		'DELETE' => EGW_ACL_DELETE,
+	);
+	/**
+	 * eGW application responsible for the handler
+	 *
+	 * @var string
+	 */
+	var $app;
+	/**
+	 * Base url of handler, need to prefix all pathes not automatic handled by HTTP_WebDAV_Server
+	 *
+	 * @var string
+	 */
+	var $base_uri;
+	/**
+	 * principal URL
+	 *
+	 * @var string
+	 */
+	var $principalURL;
+	/**
+	 * HTTP_IF_MATCH / etag of current request / last call to _common_get_put_delete() method
+	 *
+	 * @var string
+	 */
+	var $http_if_match;
+	/**
+	 * Identified user agent
+	 *
+	 * @var string
+	 */
+	var $agent;
+
+	/**
+	 * Constructor
+	 *
+	 * @param string $app 'calendar', 'addressbook' or 'infolog'
+	 * @param int $debug=null debug-level to set
+	 * @param string $base_uri=null base url of handler
+	 * @param string $principalURL=null pricipal url of handler
+	 */
+	function __construct($app,$debug=null,$base_uri=null,$principalURL=null)
+	{
+		$this->app = $app;
+		if (!is_null($debug)) $this->debug = $debug;
+		$this->base_uri = is_null($base_uri) ? $base_uri : $_SERVER['SCRIPT_NAME'];
+		if (is_null($principalURL))
+		{
+			$this->principalURL = (@$_SERVER["HTTPS"] === "on" ? "https:" : "http:") .
+				'//'.$_SERVER['HTTP_HOST'] . $_SERVER['SCRIPT_NAME'] . '/';
+		}
+		else
+		{
+			$this->principalURL = $principalURL.'principals/users/'.
+				$GLOBALS['egw_info']['user']['account_lid'].'/';
+		}
+
+		$this->agent = self::get_agent();
+
+		$this->egw_charset = translation::charset();
+		$this->accounts = $GLOBALS['egw']->accounts;
+	}
+
+	/**
+	 * Handle propfind request for an application folder
+	 *
+	 * @param string $path
+	 * @param array $options
+	 * @param array &$files
+	 * @param int $user account_id
+	 * @return mixed boolean true on success, false on failure or string with http status (eg. '404 Not Found')
+	 */
+	abstract function propfind($path,$options,&$files,$user);
+
+	/**
+	 * Propfind callback, if interator is used
+	 *
+	 * @param string $path
+	 * @param array $filter
+	 * @param array|boolean $start false=return all or array(start,num)
+	 * @param int &$total
+	 * @return array with "files" array with values for keys path and props
+	 */
+	function &propfind_callback($path, array $filter,$start,&$total) { }
+
+	/**
+	 * Handle get request for an applications entry
+	 *
+	 * @param array &$options
+	 * @param int $id
+	 * @return mixed boolean true on success, false on failure or string with http status (eg. '404 Not Found')
+	 */
+	abstract function get(&$options,$id);
+
+	/**
+	 * Handle get request for an applications entry
+	 *
+	 * @param array &$options
+	 * @param int $id
+	 * @param int $user=null account_id of owner, default null
+	 * @return mixed boolean true on success, false on failure or string with http status (eg. '404 Not Found')
+	 */
+	abstract function put(&$options,$id,$user=null);
+
+	/**
+	 * Handle get request for an applications entry
+	 *
+	 * @param array &$options
+	 * @param int $id
+	 * @return mixed boolean true on success, false on failure or string with http status (eg. '404 Not Found')
+	 */
+	abstract function delete(&$options,$id);
+
+	/**
+	 * Read an entry
+	 *
+	 * @param string/int $id
+	 * @return array/boolean array with entry, false if no read rights, null if $id does not exist
+	 */
+	abstract function read($id);
+
+	/**
+	 * Check if user has the neccessary rights on an entry
+	 *
+	 * @param int $acl EGW_ACL_READ, EGW_ACL_EDIT or EGW_ACL_DELETE
+	 * @param array/int $entry entry-array or id
+	 * @return boolean null if entry does not exist, false if no access, true if access permitted
+	 */
+	abstract function check_access($acl,$entry);
+
+	/**
+	 * Add extra properties for collections
+	 *
+	 * @param array $props=array() regular props by the groupdav handler
+	 * @param string $displayname
+	 * @param string $base_uri=null base url of handler
+	 * @return array
+	 */
+	static function extra_properties(array $props=array(), $displayname, $base_uri=null)
+	{
+		return $props;
+	}
+
+	/**
+	 * Get the etag for an entry, can be reimplemented for other algorithm or field names
+	 *
+	 * @param array/int $event array with event or cal_id
+	 * @return string/boolean string with etag or false
+	 */
+	function get_etag($entry)
+	{
+		if (!is_array($entry))
+		{
+			$entry = $this->read($entry);
+		}
+		if (!is_array($entry) || !isset($entry['id']) || !(isset($entry['modified']) || isset($entry['etag'])))
+		{
+		//	error_log(__METHOD__."(".array2string($entry).") Cant create etag!");
+			return false;
+		}
+		return 'EGw-'.$entry['id'].':'.(isset($entry['etag']) ? $entry['etag'] : $entry['modified']).'-wGE';
+	}
+
+	/**
+	 * Convert etag to the raw etag column value (without quotes, double colon and id)
+	 *
+	 * @param string $etag
+	 * @return int
+	 */
+	static function etag2value($etag)
+	{
+		list(,$val) = explode(':',substr($etag,4,-4),2);
+
+		return $val;
+	}
+
+	/**
+	 * Handle common stuff for get, put and delete requests:
+	 *  - application rights
+	 *  - entry level acl, incl. edit and delete rights
+	 *  - etag handling for precondition failed and not modified
+	 *
+	 * @param string $method GET, PUT, DELETE
+	 * @param array &$options
+	 * @param int $id
+	 * @param boolean &$return_no_access=false if set to true on call, instead of '403 Forbidden' the entry is returned and $return_no_access===false
+	 * @return array|string entry on success, string with http-error-code on failure, null for PUT on an unknown id
+	 */
+	function _common_get_put_delete($method,&$options,$id,&$return_no_access=false)
+	{
+		if (!in_array($this->app,array('principals','groups')) && !$GLOBALS['egw_info']['user']['apps'][$this->app])
+		{
+			if ($this->debug) error_log(__METHOD__."($method,,$id) 403 Forbidden: no app rights for '$this->app'");
+			return '403 Forbidden';		// no app rights
+		}
+		$extra_acl = $this->method2acl[$method];
+		if (!($entry = $this->read($id)) && ($method != 'PUT' || $entry === false) ||
+			($extra_acl != EGW_ACL_READ && $this->check_access($extra_acl,$entry) === false))
+		{
+			if ($return_no_access && !is_null($entry))
+			{
+				if ($this->debug) error_log(__METHOD__."($method,,$id,$return_no_access) is_null(\$entry)=".(int)is_null($entry).", set to false");
+				$return_no_access = false;
+			}
+			else
+			{
+				if ($this->debug) error_log(__METHOD__."($method,,$id) 403 Forbidden/404 Not Found: read($id)==".($entry===false?'false':'null'));
+				return !is_null($entry) ? '403 Forbidden' : '404 Not Found';
+			}
+		}
+		if ($entry)
+		{
+			$etag = $this->get_etag($entry);
+			// If the clients sends an "If-Match" header ($_SERVER['HTTP_IF_MATCH']) we check with the current etag
+			// of the calendar --> on failure we return 412 Precondition failed, to not overwrite the modifications
+			if (isset($_SERVER['HTTP_IF_MATCH']))
+			{
+				if (strstr($_SERVER['HTTP_IF_MATCH'], $etag) === false)
+				{
+					$this->http_if_match = $_SERVER['HTTP_IF_MATCH'];
+					if ($this->debug) error_log(__METHOD__."($method,,$id) HTTP_IF_MATCH='$_SERVER[HTTP_IF_MATCH]', etag='$etag': 412 Precondition failed");
+					return '412 Precondition Failed';
+				}
+				else
+				{
+					$this->http_if_match = $etag;
+					// if an IF_NONE_MATCH is given, check if we need to send a new export, or the current one is still up-to-date
+					if ($method == 'GET' &&	isset($_SERVER['HTTP_IF_NONE_MATCH']))
+					{
+						if ($this->debug) error_log(__METHOD__."($method,,$id) HTTP_IF_NONE_MATCH='$_SERVER[HTTP_IF_NONE_MATCH]', etag='$etag': 304 Not Modified");
+						return '304 Not Modified';
+					}
+				}	
+			}
+			if (isset($_SERVER['HTTP_IF_NONE_MATCH']))
+			{
+				if ($this->debug) error_log(__METHOD__."($method,,$id) HTTP_IF_NONE_MATCH='$_SERVER[HTTP_IF_NONE_MATCH]', etag='$etag': 412 Precondition failed");
+				return '412 Precondition Failed';
+			}
+		}
+		return $entry;
+	}
+
+	/**
+	 * Get the handler for the given app
+	 *
+	 * @static
+	 * @param string $app 'calendar', 'addressbook' or 'infolog'
+	 * @param int $user=null owner of the collection, default current user
+	 * @param int $debug=null debug-level to set
+	 * @param string $base_uri=null base url of handler
+	 * @param string $principalURL=null pricipal url of handler
+	 * @return groupdav_handler
+	 */
+	static function &app_handler($app,$debug=null,$base_uri=null,$principalURL=null)
+	{
+		static $handler_cache = array();
+
+		if (!array_key_exists($app,$handler_cache))
+		{
+			$class = $app.'_groupdav';
+			if (!class_exists($class) && !class_exists($class = 'groupdav_'.$app)) return null;
+
+			$handler_cache[$app] = new $class($app,$debug,$base_uri,$principalURL);
+		}
+		$handler_cache[$app]->$debug = $debug;
+		$handler_cache[$app]->$base_uri = $base_uri;
+		$handler_cache[$app]->$principalURL = $principalURL;
+
+		if ($debug) error_log(__METHOD__."('$app', '$base_uri', '$principalURL')");
+
+		return $handler_cache[$app];
+	}
+
+	/**
+	 * Identify know GroupDAV agents by HTTP_USER_AGENT header
+	 *
+	 * @return string|boolean agent name or false
+	 */
+	static function get_agent()
+	{
+		static $agent;
+
+		if (is_null($agent))
+		{
+			$agent = false;
+			// identify the agent (GroupDAV client) from the HTTP_USER_AGENT header
+			$user_agent = strtolower($_SERVER['HTTP_USER_AGENT']);
+			foreach(array(
+				'iphone'            => 'iphone',	// Apple iPhone iCal
+				'davkit'            => 'davkit',	// Apple iCal
+				'dataaccess'        => 'dataaccess',	// Apple addressbook iPhone
+				'cfnetwork'         => 'cfnetwork', // Apple Addressbook
+				'bionicmessage.net' => 'funambol',	// funambol GroupDAV connector from bionicmessage.net
+				'zideone'           => 'zideone',	// zideone outlook plugin
+				'lightning'         => 'lightning',	// Lighting (SOGo connector for addressbook)
+				'khtml'             => 'kde',		// KDE clients
+				'neon'              => 'neon'
+			) as $pattern => $name)
+			{
+				if (strpos($user_agent,$pattern) !== false)
+				{
+					$agent = $name;
+					break;
+				}
+			}
+			if (!$agent)
+			{
+				error_log("Unrecogniced GroupDAV client: HTTP_USER_AGENT='$_SERVER[HTTP_USER_AGENT]'!");
+			}
+			else
+			{
+				switch ($agent)
+				{
+					case 'cfnetwork':
+						if (preg_match('/address%20book\/([0-9.]+)/', $user_agent, $matches))
+						{
+							if ((int)$matches[1] < 868) $agent .= '_old';
+						}
+				}
+			}
+		}
+		return $agent;
+	}
+}
+
+/**
+ * Iterator for propfinds using propfind callback of a groupdav_handler to query results in chunks
+ *
+ * The propfind method just computes a filter and then returns an instance of this iterator instead of the files:
+ *
+ *	function propfind($path,$options,&$files,$user,$id='')
+ *	{
+ *		$filter = array();
+ * 		// compute filter from path, options, ...
+ *
+ * 		$files['files'] = new groupdav_propfind_iterator($this,$filter,$files['files']);
+ *
+ * 		return true;
+ * 	}
+ */
+class groupdav_propfind_iterator implements Iterator
+{
+	/**
+	 * current path
+	 *
+	 * @var string
+	 */
+	protected $path;
+
+	/**
+	 * Handler to call for entries
+	 *
+	 * @var groupdav_handler
+	 */
+	protected $handler;
+
+	/**
+	 * Filter of propfind call
+	 *
+	 * @var array
+	 */
+	protected $filter;
+
+	/**
+	 * Extra responses to return too
+	 *
+	 * @var array
+	 */
+	protected $common_files;
+
+	/**
+	 * current chunk
+	 *
+	 * @var array
+	 */
+	protected $files;
+
+
+	/**
+	 * Start value for callback
+	 *
+	 * @var int
+	 */
+	protected $start=0;
+
+	/**
+	 * Number of entries queried from callback in one call
+	 *
+	 */
+	const CHUNK_SIZE = 500;
+
+	/**
+	 * Log calls via error_log()
+	 *
+	 * @var boolean
+	 */
+	public $debug = false;
+
+	/**
+
+	/**
+	 * Constructor
+	 *
+	 * @param groupdav_handler $handler
+	 * @param array $filter filter for propfind call
+	 * @param array $files=null extra files/responses to return too
+	 */
+	public function __construct(groupdav_handler $handler, $path, array $filter,array &$files=null)
+	{
+		if ($this->debug) error_log(__METHOD__."('$path', ".array2string($filter).",)");
+		$this->path    = $path;
+		$this->handler = $handler;
+		$this->filter  = $filter;
+		$this->files   = $files;
+		$this->common_files = $files;
+		reset($this->files);
+	}
+
+	/**
+	 * Return the current element
+	 *
+	 * @return array
+	 */
+	public function current()
+	{
+		if ($this->debug) error_log(__METHOD__."() returning ".array2string(current($this->files)));
+		return current($this->files);
+	}
+
+	/**
+	 * Return the key of the current element
+	 *
+	 * @return int|string
+	 */
+	public function key()
+	{
+		$current = current($this->files);
+
+		if ($this->debug) error_log(__METHOD__."() returning ".array2string($current['path']));
+		return $current['path'];	// we return path as key
+	}
+
+	/**
+	 * Move forward to next element (called after each foreach loop)
+	 */
+	public function next()
+	{
+		if (next($this->files) !== false)
+		{
+			if ($this->debug) error_log(__METHOD__."() returning TRUE");
+			return true;
+		}
+		// try query further files via propfind callback of handler and store result in $this->files
+		$this->files = $this->handler->propfind_callback($this->path,$this->filter,array($this->start,self::CHUNK_SIZE));
+		if (!is_array($this->files) || !($entries = count($this->files)))
+		{
+			if ($this->debug) error_log(__METHOD__."() returning FALSE (no more entries)");
+			return false;	// no further entries
+		}
+		$this->start += $entries;
+		reset($this->files);
+
+		if ($this->debug) error_log(__METHOD__."() returning ".array2string(current($this->files) !== false));
+
+		return current($this->files) !== false;
+	}
+
+	/**
+	 * Rewind the Iterator to the first element (called at beginning of foreach loop)
+	 */
+	public function rewind()
+	{
+		if ($this->debug) error_log(__METHOD__."()");
+
+		// query first set of files via propfind callback of handler and store result in $this->files
+		$this->start = 0;
+		$files = $this->handler->propfind_callback($this->path,$this->filter,array($this->start,self::CHUNK_SIZE));
+		$this->files = array_merge($this->common_files, $files);
+		$this->start += self::CHUNK_SIZE;
+		reset($this->files);
+	}
+
+	/**
+	 * Checks if current position is valid
+	 *
+	 * @return boolean
+	 */
+	public function valid ()
+	{
+		if ($this->debug) error_log(__METHOD__."() returning ".array2string(current($this->files) !== false));
+		return current($this->files) !== false;
+	}
+}

phpgwapi/inc/class.groupdav_principals.inc.php

@@ -0,0 +1,484 @@
+<?php
+/**
+ * EGroupware: GroupDAV access: groupdav/caldav/carddav principals handlers
+ *
+ * @link http://www.egroupware.org
+ * @license http://opensource.org/licenses/gpl-license.php GPL - GNU General Public License
+ * @package api
+ * @subpackage groupdav
+ * @author Ralf Becker <RalfBecker-AT-outdoor-training.de>
+ * @copyright (c) 2008-10 by Ralf Becker <RalfBecker-AT-outdoor-training.de>
+ * @version $Id$
+ */
+
+/**
+ * EGroupware: GroupDAV access: groupdav/caldav/carddav principals handlers
+ */
+class groupdav_principals extends groupdav_handler
+{
+
+	/**
+	 * Constructor
+	 *
+	 * @param string $app 'calendar', 'addressbook' or 'infolog'
+	 * @param int $debug=null debug-level to set
+	 * @param string $base_uri=null base url of handler
+	 * @param string $principalURL=null pricipal url of handler
+	 */
+	function __construct($app,$debug=null,$base_uri=null,$principalURL=null)
+	{
+		parent::__construct($app,$debug,$base_uri,$principalURL);
+	}
+
+	/**
+	 * Handle propfind request for an application folder
+	 *
+	 * @param string $path
+	 * @param array $options
+	 * @param array &$files
+	 * @param int $user account_id
+	 * @return mixed boolean true on success, false on failure or string with http status (eg. '404 Not Found')
+	 */
+	function propfind($path,$options,&$files,$user)
+	{
+		// we do NOT support REPORTS on pricipals yet
+		// required for Apple Addressbook on Mac (addressbook-findshared REPORT)
+		if ($options['root']['name'] && $options['root']['name'] != 'propfind')
+		{
+			return '501 Not Implemented';
+		}
+		list(,$principals,$type,$name,$rest) = explode('/',$path,5);
+		// /principals/users/$name/
+		//            /users/$name/calendar-proxy-read/
+		//            /users/$name/calendar-proxy-write/
+		//            /groups/$name/
+		//            /resources/$resource/
+		//            /__uids__/$uid/.../
+
+		switch($type)
+		{
+			case 'users':
+				$files['files'] = $this->propfind_users($name,$rest,$options);
+				break;
+			case 'groups':
+				$files['files'] = $this->propfind_groups($name,$rest,$options);
+				break;
+			case 'resources':
+				$files['files'] = $this->propfind_resources($name,$rest,$options);
+				break;
+			case '__uids__':
+				$files['files'] = $this->propfind_uids($name,$rest,$options);
+				break;
+			case '':
+				$files['files'] = $this->propfind_principals($options);
+				break;
+			default:
+				return '404 Not Found';
+		}
+		if (!is_array($files['files']))
+		{
+			return $files['files'];
+		}
+		return true;
+
+		list(,,$id) = explode('/',$path);
+		if ($id && !($id = $this->accounts->id2name($id)))
+		{
+			return false;
+		}
+		foreach($id ? array($this->accounts->read($id)) : $this->accounts->search(array('type' => 'accounts')) as $account)
+		{
+			$displayname = translation::convert($account['account_fullname'],
+				translation::charset(),'utf-8');
+			
+			$props = array(
+				HTTP_WebDAV_Server::mkprop('displayname',$displayname),
+				HTTP_WebDAV_Server::mkprop('getetag',$this->get_etag($account)),
+				HTTP_WebDAV_Server::mkprop('resourcetype',array(
+					HTTP_WebDAV_Server::mkprop('principal', ''))),
+				HTTP_WebDAV_Server::mkprop('alternate-URI-set',''),
+				HTTP_WebDAV_Server::mkprop('principal-URL',$this->base_uri.'/principals/'.$account['account_lid']),
+				HTTP_WebDAV_Server::mkprop(groupdav::CALDAV,'calendar-home-set',array(
+					HTTP_WebDAV_Server::mkprop('href',$this->base_uri.'/'.$account['account_lid'].'/'))),
+				HTTP_WebDAV_Server::mkprop(groupdav::CARDDAV,'addressbook-home-set',array(
+					HTTP_WebDAV_Server::mkprop('href',$this->base_uri.'/'.$account['account_lid'].'/'))),
+			);
+			
+			foreach($this->accounts->memberships($account['account_id']) as $gid => $group)
+			{
+				$props[] = HTTP_WebDAV_Server::mkprop('group-membership',$this->base_uri.'/groups/'.$group);
+			}
+			$files['files'][] = array(
+	           	'path'  => '/principals/'.$account['account_lid'],
+	           	'props' => $props,
+			);
+			if ($this->debug > 1) error_log(__METHOD__."($path) path=/principals/".$account['account_lid'].', props='.array2string($props));
+		}
+		return files;
+	}
+
+	/**
+	 * Do propfind in /pricipals/users
+	 *
+	 * @param string $name name of account or empty
+	 * @param string $rest rest of path behind account-name
+	 * @param array $options
+	 * @return array|string array with files or HTTP error code
+	 */
+	protected function propfind_users($name,$rest,array $options)
+	{
+		//echo "<p>".__METHOD__."($name,$rest,".array2string($options).")</p>\n";
+		if (empty($name))
+		{
+			$files = array();
+			// add /pricipals/users/ entry
+			$files[] = $this->add_collection('/principals/users/',array(
+				HTTP_WebDAV_Server::mkprop('current-user-principal',array(
+					HTTP_WebDAV_Server::mkprop('href',$this->base_uri.'/principals/users/'.$GLOBALS['egw_info']['user']['account_lid'].'/'))),
+			));
+			if ($options['depth'])
+			{
+				// add all users
+				foreach($this->accounts->search(array('type' => 'accounts')) as $account)
+				{
+					$files[] = $this->add_account($account);
+				}
+			}
+		}
+		else
+		{
+			if (!($id = $this->accounts->name2id($name,'account_lid','u')) ||
+				!($account = $this->accounts->read($id)))
+			{
+				return '404 Not Found';
+			}
+			switch((string)$rest)
+			{
+				case '':
+					$files[] = $this->add_account($account);
+					if ($options['depth'])
+					{
+						$files[] = $this->add_collection('/principals/users/'.$account['account_lid'].'/calendar-proxy-read');
+						$files[] = $this->add_collection('/principals/users/'.$account['account_lid'].'/calendar-proxy-write');
+					}
+					break;
+				case 'calendar-proxy-read':
+				case 'calendar-proxy-write':
+					$files = array();
+					$files[] = $this->add_collection('/principals/users/'.$account['account_lid'].'/'.$rest);
+					// add proxys
+					break;
+				default:
+					return '404 Not Found';
+			}
+		}
+		return $files;
+	}
+
+	/**
+	 * Do propfind in /pricipals/groups
+	 *
+	 * @param string $name name of group or empty
+	 * @param string $rest rest of path behind account-name
+	 * @param array $options
+	 * @return array|string array with files or HTTP error code
+	 */
+	protected function propfind_groups($name,$rest,array $options)
+	{
+		//echo "<p>".__METHOD__."($name,$rest,".array2string($options).")</p>\n";
+		if (empty($name))
+		{
+			$files = array();
+			// add /pricipals/users/ entry
+			$files[] = $this->add_collection('/principals/groups/',array(
+				HTTP_WebDAV_Server::mkprop('current-user-principal',array(
+					HTTP_WebDAV_Server::mkprop('href',$this->base_uri.'/principals/users/'.$GLOBALS['egw_info']['user']['account_lid'].'/'))),
+			));
+			if ($options['depth'])
+			{
+				// add all users
+				foreach($this->accounts->search(array('type' => 'groups')) as $account)
+				{
+					$files[] = $this->add_group($account);
+				}
+			}
+		}
+		else
+		{
+			if (!($id = $this->accounts->name2id($name,'account_lid','g')) ||
+				!($account = $this->accounts->read($id)))
+			{
+				return '404 Not Found';
+			}
+			switch((string)$rest)
+			{
+				case '':
+					$files[] = $this->add_group($account);
+					$files[] = $this->add_collection('/principals/groups/'.$account['account_lid'].'/calendar-proxy-read');
+					$files[] = $this->add_collection('/principals/groups/'.$account['account_lid'].'/calendar-proxy-write');
+					break;
+				case 'calendar-proxy-read':
+				case 'calendar-proxy-write':
+					$files = array();
+					$files[] = $this->add_collection('/principals/groups/'.$account['account_lid'].'/'.$rest);
+					// add proxys
+					break;
+				default:
+					return '404 Not Found';
+			}
+		}
+		return $files;
+	}
+
+	/**
+	 * Add collection of a single account to a collection
+	 *
+	 * @param array $account
+	 * @return array with values for keys 'path' and 'props'
+	 */
+	protected function add_account(array $account)
+	{
+		//echo "<p>".__METHOD__."(".array2string($account).")</p>\n";
+
+		$displayname = translation::convert($account['account_fullname'],
+				translation::charset(),'utf-8');
+		$memberships = array();
+		foreach($this->accounts->memberships($account['account_id']) as $gid => $group)
+		{
+			if ($group)
+			{
+				$memberships[] = HTTP_WebDAV_Server::mkprop('href',
+					$this->base_uri.'/principals/groups/'.$group);
+			}
+		}
+		$props = array(
+			HTTP_WebDAV_Server::mkprop('displayname',$displayname),
+			HTTP_WebDAV_Server::mkprop('getetag',$this->get_etag($account)),
+			HTTP_WebDAV_Server::mkprop('resourcetype',array(
+					HTTP_WebDAV_Server::mkprop('principal', ''))),
+			HTTP_WebDAV_Server::mkprop('alternate-URI-set',array(
+				HTTP_WebDAV_Server::mkprop('href','MAILTO:'.$account['account_email']))),
+			HTTP_WebDAV_Server::mkprop('principal-URL',array(
+				HTTP_WebDAV_Server::mkprop('href',$this->base_uri.'/principals/users/'.$account['account_lid'].'/'))),
+			HTTP_WebDAV_Server::mkprop(groupdav::CALDAV,'calendar-home-set',array(
+				HTTP_WebDAV_Server::mkprop('href',$this->base_uri.'/'.$account['account_lid'].'/'))),
+			HTTP_WebDAV_Server::mkprop(groupdav::CALDAV,'calendar-user-address-set',array(
+				HTTP_WebDAV_Server::mkprop('href','MAILTO:'.$account['account_email']),
+				HTTP_WebDAV_Server::mkprop('href',$this->base_uri.'/principals/users/'.$account['account_lid'].'/'),
+				HTTP_WebDAV_Server::mkprop('href','urn:uuid:'.$account['account_lid']))),
+			HTTP_WebDAV_Server::mkprop(groupdav::CALDAV,'schedule-outbox-URL',array(
+				HTTP_WebDAV_Server::mkprop(groupdav::DAV,'href',$this->base_uri.'/calendar/'))),
+			HTTP_WebDAV_Server::mkprop(groupdav::CALENDARSERVER,'email-address-set',array(
+			HTTP_WebDAV_Server::mkprop(groupdav::CALENDARSERVER,'email-address',$account['account_email']))),
+			HTTP_WebDAV_Server::mkprop(groupdav::CALENDARSERVER,'last-name',$account['account_lastname']),
+			HTTP_WebDAV_Server::mkprop(groupdav::CALENDARSERVER,'first-name',$account['account_firstname']),
+			HTTP_WebDAV_Server::mkprop(groupdav::CALENDARSERVER,'record-type','user'),
+			HTTP_WebDAV_Server::mkprop(groupdav::CALDAV,'calendar-user-type','INDIVIDUAL'),
+			HTTP_WebDAV_Server::mkprop(groupdav::CARDDAV,'addressbook-home-set',array(
+				HTTP_WebDAV_Server::mkprop('href',$this->base_uri.'/'.$account['account_lid'].'/'))),
+			HTTP_WebDAV_Server::mkprop('group-member-ship', $memberships),
+			HTTP_WebDAV_Server::mkprop('supported-report-set',array(
+			HTTP_WebDAV_Server::mkprop('supported-report',array(
+				HTTP_WebDAV_Server::mkprop('report',array(
+					HTTP_WebDAV_Server::mkprop('acl-principal-prop-set'))))))),
+		);
+		if ($this->debug > 1) error_log(__METHOD__."($path) path=/principals/users/".$account['account_lid'].', props='.array2string($props));
+		return array(
+			'path' => '/principals/users/'.$account['account_lid'].'/',
+			'props' => $props,
+		);
+	}
+
+	/**
+	 * Add collection of a single group to a collection
+	 *
+	 * @param array $account
+	 * @return array with values for keys 'path' and 'props'
+	 */
+	protected function add_group(array $account)
+	{
+		$displayname = translation::convert(lang('Group').' '.$account['account_lid'],
+			translation::charset(),'utf-8');
+		$members = array();
+		foreach($this->accounts->members($account['account_id']) as $gid => $user)
+		{
+			if ($user)
+			{
+				$members[] = HTTP_WebDAV_Server::mkprop('href',
+					$this->base_uri.'/principals/users/'.$user);
+			}
+		}
+		$props = array(
+			HTTP_WebDAV_Server::mkprop('displayname',$displayname),
+			HTTP_WebDAV_Server::mkprop('getetag',$this->get_etag($account)),
+			HTTP_WebDAV_Server::mkprop('resourcetype',array(
+					HTTP_WebDAV_Server::mkprop('principal', ''))),
+			HTTP_WebDAV_Server::mkprop('alternate-URI-set',''),
+			HTTP_WebDAV_Server::mkprop(groupdav::CALDAV,'calendar-home-set',array(
+				HTTP_WebDAV_Server::mkprop('href',$this->base_uri.'/'.$account['account_lid'].'/'))),
+			HTTP_WebDAV_Server::mkprop(groupdav::CARDDAV,'addressbook-home-set',array(
+				HTTP_WebDAV_Server::mkprop('href',$this->base_uri.'/'.$account['account_lid'].'/'))),
+			HTTP_WebDAV_Server::mkprop(groupdav::CALENDARSERVER,'record-type','group'),
+			HTTP_WebDAV_Server::mkprop(groupdav::CALDAV,'calendar-user-type','GROUP'),
+			HTTP_WebDAV_Server::mkprop('group-member-set', $members),
+			//HTTP_WebDAV_Server::mkprop('principal-URL',array(self::mkprop('href',$this->principalURL))),
+		);
+		$files['files'][] = array(
+			'path'  => '/principals/groups/'.$account['account_lid'].'/',
+			'props' => $props,
+		);
+		if ($this->debug > 1) error_log(__METHOD__."($path) path=/principals/groups/".$account['account_lid'].', props='.array2string($props));
+		return array(
+			'path' => '/principals/groups/'.$account['account_lid'].'/',
+			'props' => $props,
+		);
+	}
+
+	/**
+	 * Add a collection
+	 *
+	 * @param string $path
+	 * @param array $props=array() extra properties 'resourcetype' is added anyway
+	 * @return array
+	 */
+	protected function add_collection($path,$props=array())
+	{
+		//echo "<p>".__METHOD__."($path,".array($props).")</p>\n";
+		$props[] = HTTP_WebDAV_Server::mkprop('resourcetype',array(
+			HTTP_WebDAV_Server::mkprop('collection',''),
+			HTTP_WebDAV_Server::mkprop('resourcetype',array(
+					HTTP_WebDAV_Server::mkprop('principal', ''))),
+		));
+		return array(
+			'path' => $path,
+			'props' => $props,
+		);
+	}
+
+	/**
+	 * Do propfind of /pricipals
+	 *
+	 * @param string $name name of group or empty
+	 * @param string $rest name of rest of path behind group-name
+	 * @param array $options
+	 * @return array|string array with files or HTTP error code
+	 */
+	protected function propfind_principals(array $options)
+	{
+		//echo "<p>".__METHOD__."(".array($options).")</p>\n";
+		$files = array();
+		$files[] = $this->add_collection('/principals/',array(
+			HTTP_WebDAV_Server::mkprop('current-user-principal',array(
+				HTTP_WebDAV_Server::mkprop('href',$this->base_uri.'/principals/users/'.$GLOBALS['egw_info']['user']['account_lid'].'/'))),
+		));
+
+		if ($options['depth'])
+		{
+			$options['depth'] = 0;
+			$files = array_merge($files,$this->propfind_users('','',$options));
+			$files = array_merge($files,$this->propfind_groups('','',$options));
+			//$files = array_merge($this->propfind_resources('','',$options));
+			//$files = array_merge($this->propfind_uids('','',$options));
+		}
+		return $files;
+	}
+
+	/**
+	 * Handle get request for an applications entry
+	 *
+	 * @param array &$options
+	 * @param int $id
+	 * @return mixed boolean true on success, false on failure or string with http status (eg. '404 Not Found')
+	 */
+	function get(&$options,$id)
+	{
+		if (!is_array($account = $this->_common_get_put_delete('GET',$options,$id)))
+		{
+			return $account;
+		}
+		$name = $GLOBALS['egw']->translation->convert(
+			trim($account['account_firstname'].' '.$account['account_lastname']),
+			$GLOBALS['egw']->translation->charset(),'utf-8');
+		$options['data'] = 'Principal: '.$account['account_lid'].
+			"\nURL: ".$this->base_uri.$options['path'].
+			"\nName: ".$name.
+			"\nEmail: ".$account['account_email'].
+			"\nMemberships: ".implode(', ',$this->accounts->memberships($id))."\n";
+		$options['mimetype'] = 'text/plain; charset=utf-8';
+		header('Content-Encoding: identity');
+		header('ETag: '.$this->get_etag($account));
+		return true;
+	}
+
+	/**
+	 * Handle get request for an applications entry
+	 *
+	 * @param array &$options
+	 * @param int $id
+	 * @param int $user=null account_id of owner, default null
+	 * @return mixed boolean true on success, false on failure or string with http status (eg. '404 Not Found')
+	 */
+	function put(&$options,$id,$user=null)
+	{
+		return false;
+	}
+
+	/**
+	 * Handle get request for an applications entry
+	 *
+	 * @param array &$options
+	 * @param int $id
+	 * @return mixed boolean true on success, false on failure or string with http status (eg. '404 Not Found')
+	 */
+	function delete(&$options,$id)
+	{
+		return false;
+	}
+
+	/**
+	 * Read an entry
+	 *
+	 * @param string/int $id
+	 * @return array/boolean array with entry, false if no read rights, null if $id does not exist
+	 */
+	function read($id)
+	{
+		return false;
+		//return $this->accounts->read($id);
+	}
+
+	/**
+	 * Check if user has the neccessary rights on an entry
+	 *
+	 * @param int $acl EGW_ACL_READ, EGW_ACL_EDIT or EGW_ACL_DELETE
+	 * @param array/int $entry entry-array or id
+	 * @return boolean null if entry does not exist, false if no access, true if access permitted
+	 */
+	function check_access($acl,$entry)
+	{
+		if ($acl != EGW_ACL_READ)
+		{
+			return false;
+		}
+		if (!is_array($entry) && !$this->accounts->name2id($entry,'account_lid','u'))
+		{
+			return null;
+		}
+		return true;
+	}
+
+	/**
+	 * Get the etag for an entry, can be reimplemented for other algorithm or field names
+	 *
+	 * @param array/int $event array with event or cal_id
+	 * @return string/boolean string with etag or false
+	 */
+	function get_etag($account)
+	{
+		if (!is_array($account))
+		{
+			$account = $this->read($account);
+		}
+		return 'EGw-'.$account['account_id'].':'.md5(serialize($account)).'-wGE';
+	}
+}