Send message just before disconnect, make sure arrives

[Christoph_Auer]

Hi!

@brunofierens

If you just want to make sure all queued packets were sent then I would suggest using TForm.OnCloseQuery to hide the application and check TTMSMQTTClient.Session.HasOutgoingPackets before disconnecting and closing the application.

Thank you, this works:

procedure TForm1.DisconnectMqtt();
begin
  mqttClient.Publish('test/is_online', 'False', qosExactlyOnce, True);
  while mqttClient.Session.HasOutgoingPackets do begin
    Sleep(2);
  end;

  mqttClient.Disconnect;
end;

So why not introduce a parameter to the Disconnect function which does exactly that?