How can I detect when the server has disconnected a client connection?

Data Abstract
1

I have a client application that is connecting to a DA server using IpSuperTcpClientChannel. Is there a way to detect when the server has disconnected the client following the timeout specified in MemorySessionManager.Timeout.

I’ve tried checking the following:
ClientChannel.Active - this is always true.
ClientChannel.Connected - this is always true.
ClientChannel.OnDisconnected - this never fires.

This is a .net client connecting to a .net server, I’m using Oxygene in both.

Thanks for your help

2

Hi,

You have mixed 2 different situations:

  • expired session
  • channel connection

when session is expired, it just clears current session and have no influence to channel.

when client accesses to expired session, server-side fires SessionNotFoundException exception.

Client-side can handle this exception automatically if ClientChannel.OnLoginNeeded event is assigned.

our templates suggest to use this implementation for this event:

method DataModule.ClientChannel_OnLoginNeeded(sender: Object; e: LoginNeededEventArgs);
begin
  // Performing login
  if self.LogOn(Properties.Settings.Default.UserId, Properties.Settings.Default.Password) then begin
    e.Retry := true;
    e.LoginSuccessful := true;
    exit;
  end;

  var lUserId: String;
  var lPassword: String;

  using lLogOnForm: LogOnForm := new LogOnForm() do begin
    if lLogOnForm.ShowDialog() <> DialogResult.OK then begin
      MessageBox.Show('Login canceled');
      exit;
    end;

    lUserId := lLogOnForm.UserId;
    lPassword := lLogOnForm.Password;
  end;

  if self.LogOn(lUserId, lPassword) then begin
    e.Retry := true;
    e.LoginSuccessful := true;
  end
  else begin
    MessageBox.Show('Login failed');
   end;
end;

You can call [empty] server’s method from client in loop if you want to have persistent session. for example, call every 13 min if SessionManager.Timeout is set to 15 min

3

Hi Evgeny,
Thanks for this response, it should allow me to do what I need.
Thaks for your help