egroupware_official/phpgwapi/inc/class.groupdav_handler.inc.php

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<?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 translation class
*
* @var translation
*/
var $translation;
/**
* 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;
/**
* 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 $base_uri=null base url of handler
*/
function __construct($app,$debug=null,$base_uri=null)
{
//error_log(__METHOD__." called");
$this->app = $app;
#if (!is_null($debug)) $this->debug = $debug = 3;
$this->base_uri = is_null($base_uri) ? $base_uri : $_SERVER['SCRIPT_NAME'];
$this->agent = self::get_agent();
$this->translation =& $GLOBALS['egw']->translation;
$this->egw_charset = $this->translation->charset();
}
/**
* 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 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(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
* @return array
*/
static function extra_properties(array $props=array())
{
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($entry).") Cant create etag!");
return false;
}
return '"'.$entry['id'].':'.(isset($entry['etag']) ? $entry['etag'] : $entry['modified']).'"';
}
/**
* 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,1,-1),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']) && ($this->http_if_match = $_SERVER['HTTP_IF_MATCH']) != $etag)
{
if ($this->debug) error_log(__METHOD__."($method,,$id) HTTP_IF_MATCH='$_SERVER[HTTP_IF_MATCH]', etag='$etag': 412 Precondition failed");
return '412 Precondition Failed';
}
// 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']) && $_SERVER['HTTP_IF_NONE_MATCH'] == $etag)
{
if ($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';
}
}
return $entry;
}
/**
* Get the handler for the given app
*
* @static
* @param string $app 'calendar', 'addressbook' or 'infolog'
* @param int $debug=null debug-level to set
* @param string $base_uri=null base url of handler
* @return groupdav_handler
*/
static function &app_handler($app,$debug=null,$base_uri=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);
}
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(
'davkit' => 'davkit', // Apple iCal
'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
'cadaver' => 'cadaver',
) 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]'!");
}
}
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
{
/**
* 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 $files;
/**
* Start value for callback
*
* @var int
*/
protected $start=0;
/**
* Number of entries queried from callback in one call
*
*/
const CHUNK_SIZE = 100;
/**
* 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,array $filter,array &$files=null)
{
$this->handler = $handler;
$this->filter = $filter;
$this->files = $files;
reset($this->files);
}
/**
* Return the current element
*
* @return array
*/
public function current()
{
return current($this->files);
}
/**
* Return the key of the current element
*
* @return int|string
*/
public function key()
{
$current = $this->current();
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)
{
return true;
}
if (!$this->handler)
{
return false; // no further entries
}
// try query further files via propfind callback of handler and store result in $this->files
$this->files = $this->handler->propfind_callback($this->filter,array($this->start,self::CHUNK_SIZE));
$this->start += self::CHUNK_SIZE;
reset($this->files);
if (count($this->files) < self::CHUNK_SIZE) // less entries then asked --> no further available
{
unset($this->handler);
}
return current($this->files) !== false;
}
/**
* Rewind the Iterator to the first element (called at beginning of foreach loop)
*/
public function rewind()
{
}
/**
* Checks if current position is valid
*
* @return boolean
*/
public function valid ()
{
return current($this->files) !== false;
}
}