calendar/drivers/kolab/kolab_calendar.php
Aleksander Machniak e11e26ed24 Sync v3.5.7
2021-05-09 09:09:57 +02:00

958 lines
33 KiB
PHP

<?php
/**
* Kolab calendar storage class
*
* @version @package_version@
* @author Thomas Bruederli <bruederli@kolabsys.com>
* @author Aleksander Machniak <machniak@kolabsys.com>
*
* Copyright (C) 2012-2015, Kolab Systems AG <contact@kolabsys.com>
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as
* published by the Free Software Foundation, either version 3 of the
* License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
class kolab_calendar extends kolab_storage_folder_api
{
public $ready = false;
public $rights = 'lrs';
public $editable = false;
public $attachments = true;
public $alarms = false;
public $history = false;
public $subscriptions = true;
public $categories = [];
public $storage;
public $type = 'event';
protected $cal;
protected $events = [];
protected $search_fields = ['title', 'description', 'location', 'attendees', 'categories'];
/**
* Factory method to instantiate a kolab_calendar object
*
* @param string Calendar ID (encoded IMAP folder name)
* @param object Calendar plugin object
*
* @return kolab_calendar Self instance
*/
public static function factory($id, $calendar)
{
$imap = $calendar->rc->get_storage();
$imap_folder = kolab_storage::id_decode($id);
$info = $imap->folder_info($imap_folder, true);
if (
empty($info)
|| !empty($info['noselect'])
|| strpos(kolab_storage::folder_type($imap_folder), 'event') !== 0
) {
return new kolab_user_calendar($imap_folder, $calendar);
}
return new kolab_calendar($imap_folder, $calendar);
}
/**
* Default constructor
*/
public function __construct($imap_folder, $calendar)
{
$this->cal = $calendar;
$this->imap = $calendar->rc->get_storage();
$this->name = $imap_folder;
// ID is derrived from folder name
$this->id = kolab_storage::folder_id($this->name, true);
$old_id = kolab_storage::folder_id($this->name, false);
// fetch objects from the given IMAP folder
$this->storage = kolab_storage::get_folder($this->name);
$this->ready = $this->storage && $this->storage->valid;
// Set writeable and alarms flags according to folder permissions
if ($this->ready) {
if ($this->storage->get_namespace() == 'personal') {
$this->editable = true;
$this->rights = 'lrswikxteav';
$this->alarms = true;
}
else {
$rights = $this->storage->get_myrights();
if ($rights && !PEAR::isError($rights)) {
$this->rights = $rights;
if (strpos($rights, 't') !== false || strpos($rights, 'd') !== false) {
$this->editable = strpos($rights, 'i');;
}
}
}
// user-specific alarms settings win
$prefs = $this->cal->rc->config->get('kolab_calendars', []);
if (isset($prefs[$this->id]['showalarms'])) {
$this->alarms = $prefs[$this->id]['showalarms'];
}
else if (isset($prefs[$old_id]['showalarms'])) {
$this->alarms = $prefs[$old_id]['showalarms'];
}
}
$this->default = $this->storage->default;
$this->subtype = $this->storage->subtype;
}
/**
* Getter for the IMAP folder name
*
* @return string Name of the IMAP folder
*/
public function get_realname()
{
return $this->name;
}
/**
*
*/
public function get_title()
{
return null;
}
/**
* Return color to display this calendar
*/
public function get_color($default = null)
{
// color is defined in folder METADATA
if ($color = $this->storage->get_color()) {
return $color;
}
// calendar color is stored in user prefs (temporary solution)
$prefs = $this->cal->rc->config->get('kolab_calendars', []);
if (!empty($prefs[$this->id]) && !empty($prefs[$this->id]['color'])) {
return $prefs[$this->id]['color'];
}
return $default ?: 'cc0000';
}
/**
* Compose an URL for CalDAV access to this calendar (if configured)
*/
public function get_caldav_url()
{
if ($template = $this->cal->rc->config->get('calendar_caldav_url', null)) {
return strtr($template, [
'%h' => $_SERVER['HTTP_HOST'],
'%u' => urlencode($this->cal->rc->get_user_name()),
'%i' => urlencode($this->storage->get_uid()),
'%n' => urlencode($this->name),
]);
}
return false;
}
/**
* Update properties of this calendar folder
*
* @see calendar_driver::edit_calendar()
*/
public function update(&$prop)
{
$prop['oldname'] = $this->get_realname();
$newfolder = kolab_storage::folder_update($prop);
if ($newfolder === false) {
$this->cal->last_error = $this->cal->gettext(kolab_storage::$last_error);
return false;
}
// create ID
return kolab_storage::folder_id($newfolder);
}
/**
* Getter for a single event object
*/
public function get_event($id)
{
// remove our occurrence identifier if it's there
$master_id = preg_replace('/-\d{8}(T\d{6})?$/', '', $id);
// directly access storage object
if (empty($this->events[$id]) && $master_id == $id && ($record = $this->storage->get_object($id))) {
$this->events[$id] = $this->_to_driver_event($record, true);
}
// maybe a recurring instance is requested
if (empty($this->events[$id]) && $master_id != $id) {
$instance_id = substr($id, strlen($master_id) + 1);
if ($record = $this->storage->get_object($master_id)) {
$master = $this->_to_driver_event($record);
}
if ($master) {
// check for match in top-level exceptions (aka loose single occurrences)
if (!empty($master['_formatobj']) && ($instance = $master['_formatobj']->get_instance($instance_id))) {
$this->events[$id] = $this->_to_driver_event($instance, false, true, $master);
}
// check for match on the first instance already
else if (!empty($master['_instance']) && $master['_instance'] == $instance_id) {
$this->events[$id] = $master;
}
else if (!empty($master['recurrence'])) {
$start_date = $master['start'];
// For performance reasons we'll get only the specific instance
if (($date = substr($id, strlen($master_id) + 1, 8)) && strlen($date) == 8 && is_numeric($date)) {
$start_date = new DateTime($date . 'T000000', $master['start']->getTimezone());
}
$this->get_recurring_events($record, $start_date, null, $id, 1);
}
}
}
return $this->events[$id];
}
/**
* Get attachment body
* @see calendar_driver::get_attachment_body()
*/
public function get_attachment_body($id, $event)
{
if (!$this->ready) {
return false;
}
$data = $this->storage->get_attachment($event['id'], $id);
if ($data == null) {
// try again with master UID
$uid = preg_replace('/-\d+(T\d{6})?$/', '', $event['id']);
if ($uid != $event['id']) {
$data = $this->storage->get_attachment($uid, $id);
}
}
return $data;
}
/**
* @param int Event's new start (unix timestamp)
* @param int Event's new end (unix timestamp)
* @param string Search query (optional)
* @param bool Include virtual events (optional)
* @param array Additional parameters to query storage
* @param array Additional query to filter events
*
* @return array A list of event records
*/
public function list_events($start, $end, $search = null, $virtual = 1, $query = [], $filter_query = null)
{
// convert to DateTime for comparisons
// #5190: make the range a little bit wider
// to workaround possible timezone differences
try {
$start = new DateTime('@' . ($start - 12 * 3600));
}
catch (Exception $e) {
$start = new DateTime('@0');
}
try {
$end = new DateTime('@' . ($end + 12 * 3600));
}
catch (Exception $e) {
$end = new DateTime('today +10 years');
}
// get email addresses of the current user
$user_emails = $this->cal->get_user_emails();
// query Kolab storage
$query[] = ['dtstart', '<=', $end];
$query[] = ['dtend', '>=', $start];
if (is_array($filter_query)) {
$query = array_merge($query, $filter_query);
}
$words = [];
$partstat_exclude = [];
$events = [];
if (!empty($search)) {
$search = mb_strtolower($search);
$words = rcube_utils::tokenize_string($search, 1);
foreach (rcube_utils::normalize_string($search, true) as $word) {
$query[] = ['words', 'LIKE', $word];
}
}
// set partstat filter to skip pending and declined invitations
if (empty($filter_query)
&& $this->cal->rc->config->get('kolab_invitation_calendars')
&& $this->get_namespace() != 'other'
) {
$partstat_exclude = ['NEEDS-ACTION', 'DECLINED'];
}
foreach ($this->storage->select($query) as $record) {
$event = $this->_to_driver_event($record, !$virtual, false);
// remember seen categories
if (!empty($event['categories'])) {
$cat = is_array($event['categories']) ? $event['categories'][0] : $event['categories'];
$this->categories[$cat]++;
}
// list events in requested time window
if ($event['start'] <= $end && $event['end'] >= $start) {
unset($event['_attendees']);
$add = true;
// skip the first instance of a recurring event if listed in exdate
if ($virtual && !empty($event['recurrence']['EXDATE'])) {
$event_date = $event['start']->format('Ymd');
$event_tz = $event['start']->getTimezone();
foreach ((array) $event['recurrence']['EXDATE'] as $exdate) {
$ex = clone $exdate;
$ex->setTimezone($event_tz);
if ($ex->format('Ymd') == $event_date) {
$add = false;
break;
}
}
}
// find and merge exception for the first instance
if ($virtual && !empty($event['recurrence']) && !empty($event['recurrence']['EXCEPTIONS'])) {
foreach ($event['recurrence']['EXCEPTIONS'] as $exception) {
if ($event['_instance'] == $exception['_instance']) {
unset($exception['calendar'], $exception['className'], $exception['_folder_id']);
// clone date objects from main event before adjusting them with exception data
if (is_object($event['start'])) {
$event['start'] = clone $record['start'];
}
if (is_object($event['end'])) {
$event['end'] = clone $record['end'];
}
kolab_driver::merge_exception_data($event, $exception);
}
}
}
if ($add) {
$events[] = $event;
}
}
// resolve recurring events
if (!empty($record['recurrence']) && $virtual == 1) {
$events = array_merge($events, $this->get_recurring_events($record, $start, $end));
}
// add top-level exceptions (aka loose single occurrences)
else if (!empty($record['exceptions'])) {
foreach ($record['exceptions'] as $ex) {
$component = $this->_to_driver_event($ex, false, false, $record);
if ($component['start'] <= $end && $component['end'] >= $start) {
$events[] = $component;
}
}
}
}
// post-filter all events by fulltext search and partstat values
$me = $this;
$events = array_filter($events, function($event) use ($words, $partstat_exclude, $user_emails, $me) {
// fulltext search
if (count($words)) {
$hits = 0;
foreach ($words as $word) {
$hits += $me->fulltext_match($event, $word, false);
}
if ($hits < count($words)) {
return false;
}
}
// partstat filter
if (count($partstat_exclude) && !empty($event['attendees'])) {
foreach ($event['attendees'] as $attendee) {
if (
in_array($attendee['email'], $user_emails)
&& in_array($attendee['status'], $partstat_exclude)
) {
return false;
}
}
}
return true;
});
// Apply event-to-mail relations
$config = kolab_storage_config::get_instance();
$config->apply_links($events);
// avoid session race conditions that will loose temporary subscriptions
$this->cal->rc->session->nowrite = true;
return $events;
}
/**
* Get number of events in the given calendar
*
* @param int Date range start (unix timestamp)
* @param int Date range end (unix timestamp)
* @param array Additional query to filter events
*
* @return int Count
*/
public function count_events($start, $end = null, $filter_query = null)
{
// convert to DateTime for comparisons
try {
$start = new DateTime('@'.$start);
}
catch (Exception $e) {
$start = new DateTime('@0');
}
if ($end) {
try {
$end = new DateTime('@'.$end);
}
catch (Exception $e) {
$end = null;
}
}
// query Kolab storage
$query[] = ['dtend', '>=', $start];
if ($end) {
$query[] = ['dtstart', '<=', $end];
}
// add query to exclude pending/declined invitations
if (empty($filter_query)) {
foreach ($this->cal->get_user_emails() as $email) {
$query[] = ['tags', '!=', 'x-partstat:' . $email . ':needs-action'];
$query[] = ['tags', '!=', 'x-partstat:' . $email . ':declined'];
}
}
else if (is_array($filter_query)) {
$query = array_merge($query, $filter_query);
}
// we rely the Kolab storage query (no post-filtering)
return $this->storage->count($query);
}
/**
* Create a new event record
*
* @see calendar_driver::new_event()
*
* @return array|false The created record ID on success, False on error
*/
public function insert_event($event)
{
if (!is_array($event)) {
return false;
}
// email links are stored separately
$links = !empty($event['links']) ? $event['links'] : [];
unset($event['links']);
//generate new event from RC input
$object = $this->_from_driver_event($event);
$saved = $this->storage->save($object, 'event');
if (!$saved) {
rcube::raise_error([
'code' => 600, 'file' => __FILE__, 'line' => __LINE__,
'message' => "Error saving event object to Kolab server"
],
true, false
);
$saved = false;
}
else {
// save links in configuration.relation object
if ($this->save_links($event['uid'], $links)) {
$object['links'] = $links;
}
$this->events = [$event['uid'] => $this->_to_driver_event($object, true)];
}
return $saved;
}
/**
* Update a specific event record
*
* @see calendar_driver::new_event()
*
* @return bool True on success, False on error
*/
public function update_event($event, $exception_id = null)
{
$updated = false;
$old = $this->storage->get_object(!empty($event['uid']) ? $event['uid'] : $event['id']);
if (!$old || PEAR::isError($old)) {
return false;
}
// email links are stored separately
$links = !empty($event['links']) ? $event['links'] : [];
unset($event['links']);
$object = $this->_from_driver_event($event, $old);
$saved = $this->storage->save($object, 'event', $old['uid']);
if (!$saved) {
rcube::raise_error([
'code' => 600, 'file' => __FILE__, 'line' => __LINE__,
'message' => "Error saving event object to Kolab server"
],
true, false
);
}
else {
// save links in configuration.relation object
if ($this->save_links($event['uid'], $links)) {
$object['links'] = $links;
}
$updated = true;
$this->events = [$event['uid'] => $this->_to_driver_event($object, true)];
// refresh local cache with recurring instances
if ($exception_id) {
$this->get_recurring_events($object, $event['start'], $event['end'], $exception_id);
}
}
return $updated;
}
/**
* Delete an event record
*
* @see calendar_driver::remove_event()
*
* @return bool True on success, False on error
*/
public function delete_event($event, $force = true)
{
$deleted = $this->storage->delete(!empty($event['uid']) ? $event['uid'] : $event['id'], $force);
if (!$deleted) {
rcube::raise_error([
'code' => 600, 'file' => __FILE__, 'line' => __LINE__,
'message' => sprintf("Error deleting event object '%s' from Kolab server", $event['id'])
],
true, false
);
}
return $deleted;
}
/**
* Restore deleted event record
*
* @see calendar_driver::undelete_event()
*
* @return bool True on success, False on error
*/
public function restore_event($event)
{
// Make sure this is not an instance identifier
$uid = preg_replace('/-\d{8}(T\d{6})?$/', '', $event['id']);
if ($this->storage->undelete($uid)) {
return true;
}
rcube::raise_error([
'code' => 600, 'file' => __FILE__, 'line' => __LINE__,
'message' => sprintf("Error undeleting the event object '%s' from the Kolab server", $event['id'])
],
true, false
);
return false;
}
/**
* Find messages linked with an event
*/
protected function get_links($uid)
{
$storage = kolab_storage_config::get_instance();
return $storage->get_object_links($uid);
}
/**
*
*/
protected function save_links($uid, $links)
{
$storage = kolab_storage_config::get_instance();
return $storage->save_object_links($uid, (array) $links);
}
/**
* Create instances of a recurring event
*
* @param array $event Hash array with event properties
* @param DateTime $start Start date of the recurrence window
* @param DateTime $end End date of the recurrence window
* @param string $event_id ID of a specific recurring event instance
* @param int $limit Max. number of instances to return
*
* @return array List of recurring event instances
*/
public function get_recurring_events($event, $start, $end = null, $event_id = null, $limit = null)
{
if (empty($event['_formatobj'])) {
$rec = $this->storage->get_object(!empty($event['uid']) ? $event['uid'] : $event['id']);
$object = $rec['_formatobj'];
}
else {
$object = $event['_formatobj'];
}
if (!is_object($object)) {
return [];
}
// determine a reasonable end date if none given
if (!$end) {
$end = clone $event['start'];
$end->add(new DateInterval('P100Y'));
}
// read recurrence exceptions first
$events = [];
$exdata = [];
$futuredata = [];
$recurrence_id_format = libcalendaring::recurrence_id_format($event);
if (!empty($event['recurrence'])) {
// copy the recurrence rule from the master event (to be used in the UI)
$recurrence_rule = $event['recurrence'];
unset($recurrence_rule['EXCEPTIONS'], $recurrence_rule['EXDATE']);
if (!empty($event['recurrence']['EXCEPTIONS'])) {
foreach ($event['recurrence']['EXCEPTIONS'] as $exception) {
if (empty($exception['_instance'])) {
$exception['_instance'] = libcalendaring::recurrence_instance_identifier($exception, !empty($event['allday']));
}
$rec_event = $this->_to_driver_event($exception, false, false, $event);
$rec_event['id'] = $event['uid'] . '-' . $exception['_instance'];
$rec_event['isexception'] = 1;
// found the specifically requested instance: register exception (single occurrence wins)
if (
$rec_event['id'] == $event_id
&& (empty($this->events[$event_id]) || !empty($this->events[$event_id]['thisandfuture']))
) {
$rec_event['recurrence'] = $recurrence_rule;
$rec_event['recurrence_id'] = $event['uid'];
$this->events[$rec_event['id']] = $rec_event;
}
// remember this exception's date
$exdate = substr($exception['_instance'], 0, 8);
if (empty($exdata[$exdate]) || !empty($exdata[$exdate]['thisandfuture'])) {
$exdata[$exdate] = $rec_event;
}
if (!empty($rec_event['thisandfuture'])) {
$futuredata[$exdate] = $rec_event;
}
}
}
}
// found the specifically requested instance, exiting...
if ($event_id && !empty($this->events[$event_id])) {
return [$this->events[$event_id]];
}
// Check first occurrence, it might have been moved
if ($first = $exdata[$event['start']->format('Ymd')]) {
// return it only if not already in the result, but in the requested period
if (!($event['start'] <= $end && $event['end'] >= $start)
&& ($first['start'] <= $end && $first['end'] >= $start)
) {
$events[] = $first;
}
}
if ($limit && count($events) >= $limit) {
return $events;
}
// use libkolab to compute recurring events
$recurrence = new kolab_date_recurrence($object);
$i = 0;
while ($next_event = $recurrence->next_instance()) {
$datestr = $next_event['start']->format('Ymd');
$instance_id = $next_event['start']->format($recurrence_id_format);
// use this event data for future recurring instances
if (!empty($futuredata[$datestr])) {
$overlay_data = $futuredata[$datestr];
}
$rec_id = $event['uid'] . '-' . $instance_id;
$exception = !empty($exdata[$datestr]) ? $exdata[$datestr] : $overlay_data;
$event_start = $next_event['start'];
$event_end = $next_event['end'];
// copy some event from exception to get proper start/end dates
if ($exception) {
$event_copy = $next_event;
kolab_driver::merge_exception_dates($event_copy, $exception);
$event_start = $event_copy['start'];
$event_end = $event_copy['end'];
}
// add to output if in range
if (($event_start <= $end && $event_end >= $start) || ($event_id && $rec_id == $event_id)) {
$rec_event = $this->_to_driver_event($next_event, false, false, $event);
$rec_event['_instance'] = $instance_id;
$rec_event['_count'] = $i + 1;
if ($exception) {
// copy data from exception
kolab_driver::merge_exception_data($rec_event, $exception);
}
$rec_event['id'] = $rec_id;
$rec_event['recurrence_id'] = $event['uid'];
$rec_event['recurrence'] = $recurrence_rule;
unset($rec_event['_attendees']);
$events[] = $rec_event;
if ($rec_id == $event_id) {
$this->events[$rec_id] = $rec_event;
break;
}
if ($limit && count($events) >= $limit) {
return $events;
}
}
else if ($next_event['start'] > $end) {
// stop loop if out of range
break;
}
// avoid endless recursion loops
if (++$i > 100000) {
break;
}
}
return $events;
}
/**
* Convert from Kolab_Format to internal representation
*/
private function _to_driver_event($record, $noinst = false, $links = true, $master_event = null)
{
$record['calendar'] = $this->id;
// remove (possibly outdated) cached parameters
unset($record['_folder_id'], $record['className']);
if ($links && !array_key_exists('links', $record)) {
$record['links'] = $this->get_links($record['uid']);
}
$ns = $this->get_namespace();
if ($ns == 'other') {
$record['className'] = 'fc-event-ns-other';
}
if ($ns == 'other' || !$this->cal->rc->config->get('kolab_invitation_calendars')) {
$record = kolab_driver::add_partstat_class($record, ['NEEDS-ACTION', 'DECLINED'], $this->get_owner());
// Modify invitation status class name, when invitation calendars are disabled
// we'll use opacity only for declined/needs-action events
$record['className'] = str_replace('-invitation', '', $record['className']);
}
// add instance identifier to first occurrence (master event)
$recurrence_id_format = libcalendaring::recurrence_id_format($master_event ? $master_event : $record);
if (!$noinst && !empty($record['recurrence']) && empty($record['recurrence_id']) && empty($record['_instance'])) {
$record['_instance'] = $record['start']->format($recurrence_id_format);
}
else if (isset($record['recurrence_date']) && is_a($record['recurrence_date'], 'DateTime')) {
$record['_instance'] = $record['recurrence_date']->format($recurrence_id_format);
}
// clean up exception data
if (!empty($record['recurrence']) && !empty($record['recurrence']['EXCEPTIONS'])) {
array_walk($record['recurrence']['EXCEPTIONS'], function(&$exception) {
unset($exception['_mailbox'], $exception['_msguid'], $exception['_formatobj'], $exception['_attachments']);
});
}
return $record;
}
/**
* Convert the given event record into a data structure that can be passed to Kolab_Storage backend for saving
* (opposite of self::_to_driver_event())
*/
private function _from_driver_event($event, $old = [])
{
// set current user as ORGANIZER
if ($identity = $this->cal->rc->user->list_emails(true)) {
$event['attendees'] = !empty($event['attendees']) ? $event['attendees'] : [];
$found = false;
// there can be only resources on attendees list (T1484)
// let's check the existence of an organizer
foreach ($event['attendees'] as $attendee) {
if (!empty($attendee['role']) && $attendee['role'] == 'ORGANIZER') {
$found = true;
break;
}
}
if (!$found) {
$event['attendees'][] = ['role' => 'ORGANIZER', 'name' => $identity['name'], 'email' => $identity['email']];
}
$event['_owner'] = $identity['email'];
}
// remove EXDATE values if RDATE is given
if (!empty($event['recurrence']['RDATE'])) {
$event['recurrence']['EXDATE'] = [];
}
// remove recurrence information (e.g. EXDATES and EXCEPTIONS) entirely
if (!empty($event['recurrence']) && empty($event['recurrence']['FREQ']) && empty($event['recurrence']['RDATE'])) {
$event['recurrence'] = [];
}
// keep 'comment' from initial itip invitation
if (!empty($old['comment'])) {
$event['comment'] = $old['comment'];
}
// remove some internal properties which should not be cached
$cleanup_fn = function(&$event) {
unset($event['_savemode'], $event['_fromcalendar'], $event['_identity'], $event['_folder_id'],
$event['calendar'], $event['className'], $event['recurrence_id'],
$event['attachments'], $event['deleted_attachments']);
};
$cleanup_fn($event);
// clean up exception data
if (!empty($event['exceptions'])) {
array_walk($event['exceptions'], function(&$exception) use ($cleanup_fn) {
unset($exception['_mailbox'], $exception['_msguid'], $exception['_formatobj']);
$cleanup_fn($exception);
});
}
// copy meta data (starting with _) from old object
foreach ((array) $old as $key => $val) {
if (!isset($event[$key]) && $key[0] == '_') {
$event[$key] = $val;
}
}
return $event;
}
/**
* Match the given word in the event contents
*/
public function fulltext_match($event, $word, $recursive = true)
{
$hits = 0;
foreach ($this->search_fields as $col) {
if (empty($event[$col])) {
continue;
}
$sval = is_array($event[$col]) ? self::_complex2string($event[$col]) : $event[$col];
if (empty($sval)) {
continue;
}
// do a simple substring matching (to be improved)
$val = mb_strtolower($sval);
if (strpos($val, $word) !== false) {
$hits++;
break;
}
}
return $hits;
}
/**
* Convert a complex event attribute to a string value
*/
private static function _complex2string($prop)
{
static $ignorekeys = ['role', 'status', 'rsvp'];
$out = '';
if (is_array($prop)) {
foreach ($prop as $key => $val) {
if (is_numeric($key)) {
$out .= self::_complex2string($val);
}
else if (!in_array($key, $ignorekeys)) {
$out .= $val . ' ';
}
}
}
else if (is_string($prop) || is_numeric($prop)) {
$out .= $prop . ' ';
}
return rtrim($out);
}
}