public ClassViewModel() 
 {
     classDao = new ClassDao();
     userDao = new UserDao();
     discussionDao = new DiscussionDao();
     discussionService = new DiscussionService();
     classes = classDao.getClassesFromCourse(ContextUtil.Instance.Course);
 }
 public CoursesViewModel() 
 {
     courseDao = new CourseDao();
     userDao = new UserDao();
     classService = new ClassService();
     classDao = new ClassDao();
     listContent = courseDao.getAllCourses();
 }