by Json Chau.
core_course_get_contents : get detail a course thought courseid
http://localhost/webservice/rest/server.php?wstoken=28953b51167c5fbc30b3333ac2d2ff55&wsfunction=core_course_get_contents&courseid=2
core_course_get_courses : get info all course in moodle
http://localhost/webservice/rest/server.php?wstoken=28953b51167c5fbc30b3333ac2d2ff55&wsfunction=core_course_get_courses