public ActionResult Create(Instructor instructor)
{
if (ModelState.IsValid)
{
db.Instructors.Add(instructor);
db.SaveChanges();
return RedirectToAction("Index");
}
return View(instructor);
}
// update courses list after editing
private void UpdateInstructorCourses(string[] selectedCourses, Instructor instructorToUpdate)
{
if (selectedCourses == null)
{
instructorToUpdate.Courses = new List<Course>();
return;
}
var selectedCoursesHS = new HashSet<string>(selectedCourses);
var instructorCourses = new HashSet<int>
(instructorToUpdate.Courses.Select(c => c.CourseId));
foreach (var course in db.Courses)
{
if (selectedCoursesHS.Contains(course.CourseId.ToString()))
{
if (!instructorCourses.Contains(course.CourseId))
{
instructorToUpdate.Courses.Add(course);
}
}
else
{
if (instructorCourses.Contains(course.CourseId))
{
instructorToUpdate.Courses.Remove(course);
}
}
}
}
// populate list of courses for an instructor
private void PopulateAssignedCourseData(Instructor instructor)
{
var allCourses = db.Courses;
var instructorCourses = new HashSet<int>(instructor.Courses.Select(c => c.CourseId));
var viewModel = new List<AssignedCourseData>();
foreach (var course in allCourses)
{
viewModel.Add(new AssignedCourseData
{
CourseId = course.CourseId,
CourseName = course.CourseName,
Assigned = instructorCourses.Contains(course.CourseId)
});
}
ViewBag.Courses = viewModel;
}