public async Task <IActionResult> GradeAssignment(int assignmentId) { var user = await GetCurrentUserAsync(); if (user is TeacherAccount teacher) { var assignment = _assignments.GetById(assignmentId); var students = _students.GetStudentsForSchoolClass(assignment.SchoolClass.Id); var model = new GradeAssignmentModel() { Assignment = assignment, Students = students }; return(View(model)); } return(RedirectToAction("Error", "Home")); }