protected function createRecurrences($app)
 {
     global $ilUser;
     include_once './Services/Calendar/classes/class.ilCalendarRecurrences.php';
     foreach (ilCalendarRecurrences::_getRecurrences($app->getEntryId()) as $rec) {
         foreach (ilCalendarRecurrenceExclusions::getExclusionDates($app->getEntryId()) as $excl) {
             $this->writer->addLine($excl->toICal());
         }
         $this->writer->addLine($rec->toICal($ilUser->getId()));
     }
 }
 /**
  * Read entry
  *
  * @access private
  * 
  */
 private function read()
 {
     global $ilDB;
     $query = "SELECT * FROM cal_recurrence_rules " . "WHERE rule_id = " . $this->db->quote($this->recurrence_id, 'integer') . " ";
     $res = $this->db->query($query);
     while ($row = $res->fetchRow(DB_FETCHMODE_OBJECT)) {
         $this->cal_id = $row->cal_id;
         $this->recurrence_type = $row->cal_recurrence;
         $this->freq_type = $row->freq_type;
         if ($row->freq_until_date != null) {
             $this->freq_until_date = new ilDateTime($row->freq_until_date, IL_CAL_DATETIME, 'UTC');
         }
         $this->freq_until_count = $row->freq_until_count;
         $this->interval = $row->intervall;
         $this->byday = $row->byday;
         $this->byweekno = $row->byweekno;
         $this->bymonth = $row->bymonth;
         $this->bymonthday = $row->bymonthday;
         $this->byyearday = $row->byyearday;
         $this->bysetpos = $row->bysetpos;
         $this->weekstart = $row->week_start;
     }
     $this->exclusion_dates = ilCalendarRecurrenceExclusions::getExclusionDates($this->cal_id);
 }