Event Handler best practices

Remoting SDK
1

Hi,

Form my main app I want to send some messages to the connected clients. I’ve implemented the eventhandler / event repository.

However most samples are built around events being triggered in the Implementation unit. I know there is a boradcast server but adding another server for some simple messages seems overhead.

What is the preferred way to send a message to all connected clients?

I have done this from the fServerDataModule but it does not seem right:

var

ev: IMy_Writer;
i: Integer;
AList: TStringList;
begin

AList := TStringList.Create();

ROSessionManager.GetAllSessions(AList);

for i := 0 to AList.Count-1 do
begin

ev := (ROEventRepository as IPlayerEventSink_Writer);
ev.ExcludeSender := False;
ev.MyProc(StringToGUID(AList[i]),MyParam);

end;

Second question is where to place the RegisterEventClient for this scenario. I’ve done that in the RORemoteDataModuleActivate now which works but the unregister in the Deactivate does not work.

Thanks,

2

Hi,

check the HTTP Chat sample:

procedure THTTPChatServerMainForm.bbWarnShutdownClick(Sender: TObject);
var reason : string;
begin
  reason := 'The system administrator will reboot the server in 5 minutes.'#13#13+
            'Please close your applications and save your work.';

  if InputQuery('Shutdown Reason', 'Reason', reason)
    then (EventRepository as IHTTPChatServerEvents_Writer).OnSystemShutdown(EmptyGUID, 5, reason);
end;

RegisterEventClient usually should be put to the Login method of the LoginService service

3

Hi Evgeny,

Thanks that solves the first problem.

However the RegisterEventClient does nto work for me when I put it in the loginservice.login method. What would be causing that?

4

Hi,

you can have LegacyEvents = True

check the same HTTP Chat sample:

function THTTPChatService.Login(const aUserID: Unicodestring): Unicodestring;
..
    RegisterEventClient(ClientID, EID_HTTPChatEvents);
    RegisterEventClient(ClientID, EID_HTTPChatServerEvents);
5

Aaaah ok now I get it. I was setting the EventRepository and LegacyEvents on my main remote data module and not my login module. Now it works, Thanks!