Listing and reading files from Player Data Storage

You can store and retrieve per-user data in Player Data Storage using the User Cloud interface. You can't retrieve data of other players though; you can only access data of the locally signed in user.

Listing files stored in Player Data Storage

• C++
• Blueprints

To interact with Player Data Storage, first get the user cloud interface:

#include "OnlineSubsystem.h"
#include "OnlineSubsystemUtils.h"

// ...
IOnlineSubsystem* Subsystem = Online::GetSubsystem(this->GetWorld());
IOnlineUserCloudPtr UserCloud = Subsystem->GetUserCloudInterface();

Register the event handler so you know when the enumeration has completed. EnumerateUserFilesDelegateHandle is declared as an FDelegateHandle.

this->EnumerateUserFilesDelegateHandle =
    UserCloud->AddOnEnumerateUserFilesCompleteDelegate_Handle(FOnEnumerateUserFilesComplete::FDelegate::CreateUObject(
        this,
        &UMyClass::HandleEnumerateUserFilesComplete));

Then call EnumerateUserFiles using the player ID of the local user.

UserCloud->EnumerateUserFiles(*LocalUserId);

When your callback fires, you'll want to handle any errors (check bWasSuccessful), and then deregister the event handler:

void UMyClass::HandleEnumerateUserFilesComplete(
    bool bWasSuccessful,
    FUniqueNetId UserId)
{
    // Deregister the event handler.
    IOnlineSubsystem *Subsystem = Online::GetSubsystem(this->GetWorld());
    IOnlineUserCloudPtr UserCloud = Subsystem->GetUserCloudInterface();
    UserCloud->ClearOnEnumerateUserFilesCompleteDelegate_Handle(this->EnumerateUserFilesDelegateHandle);
    this->EnumerateUserFilesDelegateHandle.Reset();

    if (!bWasSuccessful)
    {
        // Enumeration didn't succeed, return error.
    }
    else 
    {
        // Enumeration was successful, do something.
    }
}

After enumeration succeeds, you can get a list of the user's files by calling GetUserFileList:

TArray<FCloudFileHeader> Files;
UserCloud->GetUserFileList(*LocalUserId, Files);
TArray<FString> FileNames;
FileNames.Reserve(Files.Num() - 1);
for (const auto& It : Files)
{
    FileNames.Add(It.FileName);
}

Reading a file from Player Data Storage

When reading files from Player Data Storage, they might need to be transparently downloaded first, so reading files is an asynchronous operation.

• C++
• Blueprints

First, register the event handler for when the file read is complete. ReadUserFileDelegateHandle is declared as an FDelegateHandle.

this->ReadUserFileDelegateHandle = 
    UserCloud->AddOnReadUserFileCompleteDelegate_Handle(FOnReadUserFileComplete::FDelegate::CreateUObject(
     this,
    &UMyClass::ReadUserFileDelegateHandle));

Then call ReadUserFile using the local player's ID and the file's name.

if (!UserCloud->ReadUserFile(*UserId, FileName))
{
    // Couldn't read user file, return error.
}

When your callback fires, you'll want to handle any errors (check bWasSuccessful), and then deregister the event handler:

void UMyClass::ReadUserFileDelegateHandle(
    bool bWasSuccessful,
    const FUniqueNetId &UserId,
    const FString &FileName)
{
    // Deregister the event handler.
    IOnlineSubsystem *Subsystem = Online::GetSubsystem(this->GetWorld());
    IOnlineUserCloudPtr UserCloud = Subsystem->GetUserCloudInterface();
    UserCloud->ClearOnReadUserFileCompleteDelegate_Handle(this->ReadUserFileDelegateHandle);
    this->ReadUserFileDelegateHandle.Reset();

    if (!bWasSuccessful)
    {
        // Failed to read user file, return error.
    }
    else
    {
        TArray<uint8> FileContents;
        if (!UserCloud->GetFileContents(UserId, FileName, FileContents))
        {
            // Failed to read user file, return error.
        }
        else
        {
            // The file data is in FileContents. If you wanted to read the file contents
            // as a save game, you could so like this:
            USaveGame *Data = UGameplayStatics::LoadGameFromMemory(FileContents);
        }
    }
}