Put it all together - Private Chat - (Unreal Engine module)

Last updated on September 4, 2025

Connect the UI with private chat

In this tutorial, you will connect your implementation in PrivateChatSubsystem_Starter to the private chat widget.

1. Open the PrivateChatWidget_Starter CPP file and start with connecting the UI to send private chat messages. Replace the SendPrivateChatMessage() code with the following code:

   void UPrivateChatWidget_Starter::SendPrivateChatMessage(const FText& MessageText)
   {
       if (!PrivateChatSubsystem)
       {
           UE_LOG_PRIVATECHAT(Warning, TEXT("Cannot send private chat message. Private Chat subsystem is not valid."));
           return;
       }
   
       if (!ensure(GetOwningPlayer()))
       {
           UE_LOG_PRIVATECHAT(Warning, TEXT("Cannot send private chat message. PlayerController is not valid."));
           return;
       }
   
       const ULocalPlayer* LocalPlayer = GetOwningPlayer()->GetLocalPlayer();
       if (!ensure(LocalPlayer))
       {
           UE_LOG_PRIVATECHAT(Warning, TEXT("Cannot send private chat message. LocalPlayer is not valid."));
           return;
       }
   
       // Send private private chat message.
       PrivateChatSubsystem->SendPrivateChatMessage(
           LocalPlayer->GetPreferredUniqueNetId().GetUniqueNetId(),
           PrivateChatRecipientUserId,
           MessageText.ToString());
   }

2. Replace the GetLastPrivateChatMessages() function with the code below to get and display the chat message history:

   void UPrivateChatWidget_Starter::GetLastPrivateChatMessages() const
   {
       if (!PrivateChatSubsystem)
       {
           UE_LOG_PRIVATECHAT(Warning, TEXT("Cannot get last private chat messages. Private Chat subsystem is not valid."));
           return;
       }
   
       if (!ensure(GetOwningPlayer()))
       {
           UE_LOG_PRIVATECHAT(Warning, TEXT("Cannot get last private chat messages. PlayerController is not valid."));
           return;
       }
   
       const ULocalPlayer* LocalPlayer = GetOwningPlayer()->GetLocalPlayer();
       if (!ensure(LocalPlayer))
       {
           UE_LOG_PRIVATECHAT(Warning, TEXT("Cannot get last private chat messages. LocalPlayer is not valid."));
           return;
       }
   
       // Get chat room id.
       const FString ChatRoomId = PrivateChatSubsystem->GetPrivateChatRoomId(
           LocalPlayer->GetPreferredUniqueNetId().GetUniqueNetId(),
           PrivateChatRecipientUserId);
   
       // Abort if room id was not found.
       if (ChatRoomId.IsEmpty())
       {
           W_Chat->SetWidgetState(EAccelByteWarsWidgetSwitcherState::Empty, NO_CHAT_MESSAGE);
           return;
       }
   
       // Get last private chat messages.
       TArray<TSharedRef<FChatMessage>> OutMessages;
       if (PrivateChatSubsystem->GetLastPrivateChatMessages(
           LocalPlayer->GetPreferredUniqueNetId().GetUniqueNetId(),
           ChatRoomId,
           W_Chat->GetMaxChatHistory(),
           OutMessages))
       {
           // Abort if last messages is empty.
           if (OutMessages.IsEmpty())
           {
               W_Chat->SetWidgetState(EAccelByteWarsWidgetSwitcherState::Empty, NO_CHAT_MESSAGE);
               return;
           }
   
           // Display last chat messages.
           Algo::Reverse(OutMessages);
           for (const TSharedRef<FChatMessage>& Message : OutMessages)
           {
               AppendChatMessage(Message.Get());
           }
       }
       // Show error message if failed.
       else 
       {
           W_Chat->SetWidgetState(EAccelByteWarsWidgetSwitcherState::Error, FAILED_TO_LOAD_CHAT_MESSAGE);
       }
   }

3. Next, replace the AppendChatMessage() function with the code below to append the chat message to be displayed with additional safeguards:

   void UPrivateChatWidget_Starter::AppendChatMessage(const FChatMessage& Message) const
   {
       if (!PrivateChatSubsystem)
       {
           UE_LOG_PRIVATECHAT(Warning, TEXT("Cannot append a private chat message to display. Private Chat subsystem is not valid."));
           return;
       }
   
       if (!ensure(GetOwningPlayer()))
       {
           UE_LOG_PRIVATECHAT(Warning, TEXT("Cannot append a private chat message to display. PlayerController is not valid."));
           return;
       }
   
       const ULocalPlayer* LocalPlayer = GetOwningPlayer()->GetLocalPlayer();
       if (!ensure(LocalPlayer))
       {
           UE_LOG_PRIVATECHAT(Warning, TEXT("Cannot append a private chat message to display. LocalPlayer is not valid."));
           return;
       }
   
       const FUniqueNetIdAccelByteUserRef SenderABId = StaticCastSharedRef<const FUniqueNetIdAccelByteUser>(Message.GetUserId());
       if (!SenderABId.Get().IsValid())
       {
           UE_LOG_PRIVATECHAT(Warning, TEXT("Cannot append a private chat message to display. Sender User Id is invalid."));
           return;
       }
   
       // Construct chat message.
       UChatData* ChatData = NewObject<UChatData>();
       ChatData->Message = Message.GetBody();
       ChatData->bIsSenderLocal = PrivateChatSubsystem->IsMessageFromLocalUser(LocalPlayer->GetPreferredUniqueNetId().GetUniqueNetId(), Message);
   
       // If the sender doesn't have display name, then use the default display name.
       ChatData->Sender = Message.GetNickname();
       if (ChatData->Sender.IsEmpty() || SenderABId.Get().GetAccelByteId().Equals(ChatData->Sender))
       {
           ChatData->Sender = UTutorialModuleOnlineUtility::GetUserDefaultDisplayName(Message.GetUserId().Get());
       }
   
       // Display chat message.
       W_Chat->AppendChatMessage(ChatData);
   }

4. Now, complete the code by binding the chat events with the widget. To do this, replace the pre-defined NativeOnActivated() function with the following code:

   void UPrivateChatWidget_Starter::NativeOnActivated()
   {
       Super::NativeOnActivated();
   
       // Reset chat widget
       W_Chat->ClearChatMessages();
       W_Chat->ClearInput();
   
       // Setup widget
       W_Chat->OnSubmitDelegates.AddUObject(this, &ThisClass::SendPrivateChatMessage);
       Btn_Back->OnClicked().AddUObject(this, &ThisClass::DeactivateWidget);
   
       if (PrivateChatSubsystem)
       {
           PrivateChatSubsystem->GetOnSendPrivateChatCompleteDelegates()->AddUObject(this, &ThisClass::OnSendPrivateChatComplete);
           PrivateChatSubsystem->GetOnPrivateChatMessageReceivedDelegates()->AddUObject(this, &ThisClass::OnPrivateChatMessageReceived);
       }
   
       // Display default state.
       GetLastPrivateChatMessages();
   }

5. Finally, unbind those events when the widget is closed. To this, replace the pre-defined NativeOnDeactivated() function with the following code:

   void UPrivateChatWidget_Starter::NativeOnDeactivated()
   {
       PrivateChatRecipientUserId = nullptr;
   
       // Cleanup widget
       W_Chat->OnSubmitDelegates.RemoveAll(this);
       Btn_Back->OnClicked().RemoveAll(this);
   
       // Unbind chat events.
       if (PrivateChatSubsystem)
       {
           PrivateChatSubsystem->GetOnSendPrivateChatCompleteDelegates()->RemoveAll(this);
           PrivateChatSubsystem->GetOnPrivateChatMessageReceivedDelegates()->RemoveAll(this);
       }
   
       Super::NativeOnDeactivated();
   }

Resources

• The files used in this tutorial section are available in the Byte Wars GitHub repository.
  • AccelByteWars/Source/AccelByteWars/TutorialModules/Social/PrivateChat/UI/PrivateChatWidget_Starter.h
  • AccelByteWars/Source/AccelByteWars/TutorialModules/Social/PrivateChat/UI/PrivateChatWidget_Starter.cpp