Adding custom variables to online subsystem searches

Development Programming & Scripting
1

So I have followed this wiki on how to interact with the online subsystem. However I can’t add any custom variables, for example it would be nice to have a user defined server name. So say I’m editing OnlineSubsystemNull to add these variables, I’ve got this far:

In OnlineSubsystemNullTypes.h

class FOnlineSessionInfoNull : public FOnlineSessionInfo
{
    ...
    FString ServerName;
    ...
};

In OnlineSessionInterfaceNull.cpp

bool FOnlineSessionNull::CreateSession(int32 HostingPlayerNum, FName SessionName, const FOnlineSessionSettings& NewSessionSettings)
{
    ...
    Session->ServerName = SessionName.ToString();
    ...
}

and finally in my FindSessions() function I cast the sessioninfo into the child class which should have the extra info-

TSharedPtr<FOnlineSessionInfoNull> Fosin = StaticCastSharedPtr<FOnlineSessionInfoNull>(SessionSearch->SearchResults[SearchIdx].Session.SessionInfo);
Whatever = Fosin->ServerName;

While everything builds correctly, the ServerName variable is always blank when I go to get it, uninitialized I suspect. It looks like everything is taken care of in the AppendSessionToPacket function and yet it doesn’t append my extra variables.

Any help?

2

To add to the mystery, using GEngine->AddOnScreenDebugMessage, I can see the servername intact as it goes into AppendSessionToPacket, but then it is blank in ReadSessionFromPacket

3

Ok so it appears the NboSerializerNull.h decides what variables in FOnlineSessionInfoNull get added to a packet. So I was successful just adding the servername to the packet in AppendSessionToPacket and reading it back out in ReadSessionFromPacket.

In OnlineSessionInterfaceNull.cpp

void FOnlineSessionNull::AppendSessionToPacket(FNboSerializeToBufferNull& Packet, FOnlineSession* Session)
{
	/** Owner of the session */
	Packet << *StaticCastSharedPtr<const FUniqueNetIdString>(Session->OwningUserId)
		<< Session->OwningUserName
		<< Session->NumOpenPrivateConnections
		<< Session->NumOpenPublicConnections;

	// Try to get the actual port the netdriver is using
	SetPortFromNetDriver(*LANSubsystem, Session->SessionInfo);
	TSharedPtr<FOnlineSessionInfoNull> FosinPtr = StaticCastSharedPtr<FOnlineSessionInfoNull>(Session->SessionInfo);
	// Write host info (host addr, session id, and key)
	Packet << *FosinPtr;
	Packet << FosinPtr->ServerName;

	// Now append per game settings
	AppendSessionSettingsToPacket(Packet, &Session->SessionSettings);
}

and

void FOnlineSessionLAN::ReadSessionFromPacket(FNboSerializeFromBufferNull& Packet, FOnlineSession* Session)
{
    ...
    Packet >> NullSessionInfo->ServerName
    ...
}