public function render_print_book_chapter_dialog_link() {
        $printtext = get_string('printchapter', 'booktool_print');
        $printicon = $this->output->pix_icon('chapter', $printtext, 'booktool_print',
                array('class' => 'icon'));
        $printlinkatt = array('onclick' => 'window.print();return false;', 'class' => 'hidden-print');
        return html_writer::link('#', $printicon . $printtext, $printlinkatt);
    }