public function switch_phase($newphase) {
        global $DB;

        $known = $this->available_phases_list();
        if (!isset($known[$newphase])) {
            return false;
        }

        if (self::PHASE_CLOSED == $newphase) {
            // push the grades into the gradebook
            $workshop = new stdclass();
            foreach ($this as $property => $value) {
                $workshop->{$property} = $value;
            }
            $workshop->course     = $this->course->id;
            $workshop->cmidnumber = $this->cm->id;
            $workshop->modname    = 'workshop';
            workshop_update_grades($workshop);
        }

        $DB->set_field('workshop', 'phase', $newphase, array('id' => $this->id));
        $this->phase = $newphase;
        $eventdata = array(
            'objectid' => $this->id,
            'context' => $this->context,
            'other' => array(
                'workshopphase' => $this->phase
            )
        );
        $event = \mod_workshop\event\phase_switched::create($eventdata);
        $event->trigger();
        return true;
    }