/** * Cover image selector. * @return bool|null|string * @throws \coding_exception * @throws \moodle_exception */ public function cover_image_selector() { global $PAGE; if (has_capability('moodle/course:changesummary', $PAGE->context)) { $vars = ['accepttypes' => local::supported_coverimage_typesstr()]; return $this->render_from_template('theme_snap/cover_image_selector', $vars); } return null; }