/** * Check whether a lesson is part of a course * * @param mixed lesson A lesson id or an EfrontLesson object * @since 3.6.3 * @access public */ public function isCourseLesson($lesson) { $lesson = EfrontLesson::convertArgumentToLessonObject($lesson); $result = eF_getTableData("lessons_to_courses", "*", "lessons_ID=" . $lesson->lesson['id'] . " and courses_ID=" . $this->course['id']); return !empty($result); }