public IView AddLecture(int courseId, string lectureName) { if (!this.HasCurrentUser) { throw new ArgumentException("There is no currently logged in user."); } if (!this.User.IsInRole(Role.Lecturer)) { throw new DivideByZeroException("The current user is not authorized to perform this operation."); } ICourse course = this.GetCourse(courseId); course.AddLecture(new Lecture("lectureName")); return(this.View(course)); }