function __construct($course_id)
 {
     global $CFG, $DB;
     $global_config = get_config('block_notifications');
     $Course = new Course();
     if (!$Course->is_registered($course_id) or !$Course->uses_notifications_block($course_id)) {
         echo get_string('rss_not_enabled', 'block_notifications');
         return;
     }
     $User = new User();
     $teacher = $User->get_professor($course_id);
     // if no teacher then add a dummy mail address
     if (empty($teacher)) {
         $teacher = new \stdClass();
         $teacher->firstname = "No";
         $teacher->lastname = "Teacher";
         $teacher->email = "*****@*****.**";
     }
     $course_info = $Course->get_course_info($course_id);
     $course_registration = $Course->get_registration($course_id);
     if ($course_registration->notify_by_rss != 1) {
         return;
         // the rss is not active in the course
     }
     $now = date('r');
     $course_name = $this->standardize($course_info->fullname);
     $course_summary = $this->standardize($course_info->summary);
     $output = "<?xml version=\"1.0\"?>\n\t\t\t\t\t<rss version=\"2.0\">\n\t\t\t\t\t<channel>\n\t\t\t\t\t<title>{$course_name}</title>\n\t\t\t\t\t<link>{$CFG->wwwroot}/course/view.php?id={$course_id}</link>\n\t\t\t\t\t<description>{$course_summary}</description>\n\t\t\t\t\t<language>en-us</language>\n\t\t\t\t\t<pubDate>{$now}</pubDate>\n\t\t\t\t\t<lastBuildDate>{$now}</lastBuildDate>\n\t\t\t\t\t<docs>{$CFG->wwwroot}/course/view.php?id={$course_id}</docs>\n\t\t\t\t\t<managingEditor>{$teacher->email} ({$teacher->firstname} {$teacher->lastname})</managingEditor>\n\t\t\t\t\t<webMaster>helpdesk@elearninglab.org (Helpdesk eLab)</webMaster>";
     $logs = $Course->get_logs($course_id, $global_config->history_length);
     $events = report_eventlist_list_generator::get_all_events_list();
     if (!isset($logs) or !is_array($logs) or count($logs) == 0) {
         $output .= "<item>";
         $output .= '<title>' . get_string('rss_empty_title', 'block_notifications') . '</title>';
         $output .= '<description>' . get_string('rss_empty_description', 'block_notifications') . '</description>';
         $output .= "</item>";
     } else {
         $separator = ' - ';
         foreach ($logs as $log) {
             $output .= "<item>";
             $output .= '<title>' . get_string($log->module, 'block_notifications') . ': ' . $this->standardize($log->name) . '</title>';
             if (preg_match('/deleted/', $log->event)) {
                 $output .= "<link></link>";
             } else {
                 $output .= "<link>" . $this->extract_url($log) . "</link>";
             }
             $output .= "<description>";
             $output .= $this->standardize(preg_replace('/\\\\.*$/', '', $events[$log->event]['raweventname']) . ' on ' . date("r", $log->time_created));
             $output .= "</description>";
             $output .= "</item>";
         }
     }
     $output .= "</channel></rss>";
     header("Content-Type: application/rss+xml");
     echo $output;
 }