public StatusTransport<StudentViewModel> SaveStudent(StudentViewModel model)
{
var transport = new StatusTransport<StudentViewModel>();
var student = new Student(model);
_context.Students.Attach(student, true);
try
{
_context.SubmitChanges();
// Retrieve most recent version.
_context.Refresh(RefreshMode.OverwriteCurrentValues, student);
transport.ViewModel = new StudentViewModel(student)
{ ClientId = model.ClientId };
transport.SetSuccess();
// Update all connected clients. Comment this line out to test
// normal conflict resolution.
BroadcastStudent(transport);
}
catch (ChangeConflictException exConflict)
{
// Retrieve most recent version.
_context.Refresh(RefreshMode.OverwriteCurrentValues, student);
transport.ViewModel = new StudentViewModel(student);
// Mark result as stale.
transport.SetStale(exConflict);
}
return transport;
}
private void BroadcastStudent(StatusTransport<StudentViewModel> transport)
{
var hub = _hubConn.CreateProxy(typeof(StudentHub).Name);
_hubConn
.Start()
.ContinueWith(_ => hub.Invoke("BroadcastUpdatedStudent", transport));
}
public StatusTransport<StudentViewModel> GetStudentById(int id)
{
var transport = new StatusTransport<StudentViewModel>();
var student = _context.Students.Single(x => x.Id == id);
transport.ViewModel = new StudentViewModel(student);
transport.SetSuccess();
return transport;
}
public void BroadcastUpdatedStudent(StatusTransport<StudentViewModel>
transport)
{
Clients.updateStudent(transport);
}
