OSS でフレンドリストのクエリを実行する - フレンドリスト - (Unreal Engine モジュール)

Last updated on May 30, 2024

What's in the Starter Pack

You previously implemented some friend functionalities in the FriendSubsystem_Starter subsystem class. You will continue to use that class to follow this tutorial.

Before you start, several delegates have been prepared for you in the /Source/AccelByteWars/TutorialModules/Social/FriendsEssentials/FriendsEssentialsModels.h file that you will use along with this tutorial.

• Delegates to be used as a callback when getting a friend list completes.

  DECLARE_DELEGATE_ThreeParams(FOnGetFriendListComplete, bool /*bWasSuccessful*/, TArray<UFriendData*> /*Friends*/, const FString& /*ErrorMessage*/);

Implement getting friend list

In this section, you will implement functionalities to get the friend list.

You have already created a function named CacheFriendList() in the FriendsSubsystem_Starter that is used to get and cache the friend list. You need to filter that cached friend list to get only the list of players that accepted a friend request.

1. Open the FriendsSubsystem_Starter class Header file and create the following function declarations.

   public:
       void GetFriendList(const APlayerController* PC, const FOnGetFriendListComplete& OnComplete = FOnGetFriendListComplete());

2. Create the definition for the function above. Open the FriendsSubsystem_Starter class CPP file and add the code below. It will filter the cached friend list to get the accepted friend list only.

   void UFriendsSubsystem_Starter::GetFriendList(const APlayerController* PC, const FOnGetFriendListComplete& OnComplete)
   {
       if (!ensure(FriendsInterface))
       {
           UE_LOG_FRIENDS_ESSENTIALS(Warning, TEXT("Cannot get friend list. Friends Interface is not valid."));
           return;
       }
   
       // Get accepted friend list from cache.
       GetCacheFriendList(PC, FOnGetCacheFriendListComplete::CreateWeakLambda(this, [this, OnComplete](bool bWasSuccessful, TArray<TSharedRef<FOnlineFriend>>& CachedFriendList, const FString& ErrorMessage)
       {
           if (bWasSuccessful)
           {
               // Filter accepted friends.
               CachedFriendList = CachedFriendList.FilterByPredicate([](const TSharedRef<FOnlineFriend>& Friend)
               {
                   return Friend->GetInviteStatus() == EInviteStatus::Accepted;
               });
   
               TArray<UFriendData*> AcceptedFriendList;
               for (const TSharedRef<FOnlineFriend>& TempData : CachedFriendList)
               {
                   AcceptedFriendList.Add(UFriendData::ConvertToFriendData(TempData));
               }
   
               OnComplete.ExecuteIfBound(true, AcceptedFriendList, TEXT(""));
           }
           else
           {
               OnComplete.ExecuteIfBound(false, TArray<UFriendData*>(), ErrorMessage);
           }
       }));
   }

Resources

• The files used in this tutorial section are available in the Unreal Byte Wars GitHub repository.
  • AccelByteWars/Source/AccelByteWars/TutorialModules/Social/FriendsEssentials/FriendsSubsystem_Starter.h
  • AccelByteWars/Source/AccelByteWars/TutorialModules/Social/FriendsEssentials/FriendsSubsystem_Starter.cpp