function toHtml() {
        global $CFG, $USER, $COURSE, $PAGE, $OUTPUT;
        require_once("$CFG->dirroot/repository/lib.php");

        // security - never ever allow guest/not logged in user to upload anything or use this element!
        if (isguestuser() or !isloggedin()) {
            print_error('noguest');
        }

        if ($this->_flagFrozen) {
            return $this->getFrozenHtml();
        }

        $id          = $this->_attributes['id'];
        $elname      = $this->_attributes['name'];
        $subdirs     = $this->_options['subdirs'];
        $maxbytes    = $this->_options['maxbytes'];
        $draftitemid = $this->getValue();
        $accepted_types = $this->_options['accepted_types'];

        if (empty($draftitemid)) {
            // no existing area info provided - let's use fresh new draft area
            require_once("$CFG->libdir/filelib.php");
            $this->setValue(file_get_unused_draft_itemid());
            $draftitemid = $this->getValue();
        }

        $client_id = uniqid();

        // filemanager options
        $options = new stdClass();
        $options->mainfile  = $this->_options['mainfile'];
        $options->maxbytes  = $this->_options['maxbytes'];
        $options->maxfiles  = $this->getMaxfiles();
        $options->client_id = $client_id;
        $options->itemid    = $draftitemid;
        $options->subdirs   = $this->_options['subdirs'];
        $options->target    = $id;
        $options->accepted_types = $accepted_types;
        $options->return_types = $this->_options['return_types'];
        $options->context = $PAGE->context;
        $options->areamaxbytes = $this->_options['areamaxbytes'];

        $html = $this->_getTabs();
        $fm = new form_filemanager($options);
        $output = $PAGE->get_renderer('core', 'files');
        $html .= $output->render($fm);

        $html .= html_writer::empty_tag('input', array('value' => $draftitemid, 'name' => $elname, 'type' => 'hidden', 'id' => $id));

        if (!empty($options->accepted_types) && $options->accepted_types != '*') {
            $html .= html_writer::tag('p', get_string('filesofthesetypes', 'form'));
            $util = new \core_form\filetypes_util();
            $filetypes = $options->accepted_types;
            $filetypedescriptions = $util->describe_file_types($filetypes);
            $html .= $OUTPUT->render_from_template('core_form/filetypes-descriptions', $filetypedescriptions);
        }

        return $html;
    }