EOS

There are 2 versions of OSS, one that’s based on OnlineSubsystem plugin, and a new plugin that started with UE5 called OnlineServices (working with EGS plugin to)

You can’t have OnlineSubsystemEOS and OnlineServicesEOS enabled or you will get errors, e.g: Lobby Server Travel fail because FSocketSubsystemEOS::GetLocalUserId will try to get logged user in Subsystem Auth Interface (and not the user logged in Online Services Auth interface)

Resources

• Starting with OSSv1 Forum Thread - Course from a UE EOS dev.
• EOS Online Framework Plugin

Logging

• Info
• Log categoires details

Account

Auth Interface VS Connect Interface

• Auth is for Epic Games accounts
• Connect supports cross play because instead of using EG account ids it will use a Product User ID (PUID)
• More info

Login

Global call stack of a successful call of Login on the identity interface.

• IOnlineIdentity::Login will call FUserManagerEOS::Login
  • will call CallEOSAuthLogin (or ConnectLoginNoEAS, LoginViaPersistentAuth, LoginViaExternalAuth)
    • will call EOS_Auth_Login, callback at OnEOSAuthLoginComplete
      • In callback: (should have Epic Account id (EAID) in EOS_Auth_LoginCallbackInfo)
        • if successful will call ConnectLoginEAS that calls EOS_Connect_Login
          • In callback: (should have PUID in EOS_Connect_LoginCallbackInfo)
            • if successful:
              • calls FullLoginCallback (having both EAID and PUID)
                • calls AddLocalUser (with EAID and PUID)
                  • calls FUniqueNetIdEOSRegistry::FindOrAdd (with EAID and PUID)
                  • fills data in the local user struct
                  • calls UpdateUserInfo
                • will call TriggerOnLoginCompleteDelegates as successful
            • if invalid user:
              • calls CreateConnectedLogin
            • if other error:
              • calls Logout and logs an Error
              • will call TriggerOnLoginCompleteDelegates as failed

User Info

Get DisplayName

About Platform parameter

if not passing platform string getting the display name can work but will provoke the following warnings:
LogEOSPresence: FPresenceClient::GetTargetPlatformTypePrivate - Target User Cache Not Found!
LogEOSRTC: FRTCClient::GetTargetPlatformTypePrivate: Unable to find local user ....

Call stack when getting user display name

• IOnlineUserPtr::GetUserInfo returns FOnlineUser
  • call FOnlineUser::GetDisplayName
    • implementation in TOnlineUserEOS::GetDisplayName
      • calls OnlineSubsystemEOSTypesPrivate::GetBestDisplayName
        • calls UserManager->GetBestDisplayName (FUserManagerEOS)
          • calls GetBestDisplayNameStr and EOS_UserInfo_BestDisplayName_Release

Lobby

• Schemas
• Schema flags list: ESchemaAttributeFlags

Searchable attributes

Searchable attributes must be declared in the LobbyBase schema id or the following error will come on Engine init config: Invalid schema attribute yourderivedschemaid.lobby.yoursearchableattribute: Searchable fields may only exist in the base schema.

Known issues

Unable to map None to EOS_OnlinePlatformType

FEpicGamesPlatform::GetOnlinePlatformType - unable to map None to EOS_OnlinePlatformType : Explanation

Overlay initialization failed

EOS First overlay initialization failed for swapchain. Disabling any future attempts to initialize.

This can be because we don’t use OnlineSubsystemEOS but OnlineServicesEOS, which cause EOS_Platform_Create inside FEOSSDKManager::CreatePlatform to be called to late (after graphics initialized).

Fix:

• Make a new Runtime module with the loading phase set to PostSplashScreen
• Add this module to your project target file (and also project editor target)
• Add the module to your .uproject module dependency list (with Runtime and PostSplashScreen)
• In your module Build.cs include as a dependency (for example in PrivateDependencyModuleNames) the OnlineServicesInterface module.
• Inside your module StartupModule, call UE::Online::GetServices(...), in my case I was calling UE::Online::GetServices(UE::Online::EOnlineServices::Epic). This will trigger the EOS Overlay to be created, and PostSplashScreen is early enough for it.