[游戏开发]UE4 DataTables保存同时自动转换成Json/Csv

UE4编辑器在文件改变的时候会回调
···
void FFileCache::OnDirectoryChanged(const TArray& FileChanges)
···

对改接口的阅读后在项目里编辑器修改模块中增加自己的代码

监听文件变化

// 在编辑器启动的时候调用
void EditorModule::LobbyDataTableInit()
{
	// 关注文件变化的目录, 不要与已有关注路径重复。
	CollectionFolders[ECollectionShareType::CST_Shared] = FPaths::ProjectContentDir() / TEXT("GameData");
	WatcherDelegate = FDelegateHandle();
	FDirectoryWatcherModule& Module = FModuleManager::LoadModuleChecked<FDirectoryWatcherModule>(TEXT("DirectoryWatcher"));

	if (IDirectoryWatcher* DirectoryWatcher = Module.Get())
	{
		for (int32 CacheIdx = 0; CacheIdx < ECollectionShareType::CST_All; ++CacheIdx)
		{
			// 设置回调函数
			auto Callback = IDirectoryWatcher::FDirectoryChanged::CreateRaw(this, &EditorModule::DataTableToJson);
			const FString& CollectionFolder = CollectionFolders[CacheIdx];

			if (CollectionFolder.IsEmpty())
			{
				continue;
			}

			// Make sure the folder we want to watch exists on disk
			if (!IFileManager::Get().MakeDirectory(*CollectionFolder, true))
			{
				continue;
			}

			DirectoryWatcher::FFileCacheConfig FileCacheConfig(FPaths::ConvertRelativePathToFull(CollectionFolder), FString());
			FileCacheConfig.DetectMoves(false);
			FileCacheConfig.RequireFileHashes(false);

			if (!DirectoryWatcher->RegisterDirectoryChangedCallback_Handle(FileCacheConfig.Directory, Callback, WatcherDelegate))
			{
				UE_LOG(LogTemp, Error, TEXT("LobbyDataTableInit. Failed registering directory watcher for folder"));
			}
		}
	}
}

文件变化的时候Json的转换

void EditorModule::DataTableToJson(const TArray<FFileChangeData>& FileChanges)
{
	// 需要转换成Json的DataTables
	TArray<FString> LobbyDataTables = UDSGameSettings::Get()->LobbyDataTables;

	// 同一文件在 FileChanges 中会有多条记录
	TMap<FString, bool> AlreadyFile;

	for (const FFileChangeData& ThisEntry : FileChanges)
	{
		
		FString FilePath = ThisEntry.Filename;
		FString FileBaseName = FPaths::GetBaseFilename(FilePath);
		
		// 单独配置了需要转换的文件名，检查是否需要转换
		if (LobbyDataTables.Find(FileBaseName) == INDEX_NONE)
		{
			continue;
		}

		// 判断文件是否需要处理 1. 文件是否已经转换过 2. 文件是否发生了内容变化
		if (!AlreadyFile.Contains(FilePath) && (ThisEntry.Action == FFileChangeData::FCA_Added  || ThisEntry.Action == FFileChangeData::FCA_Removed))
		{
			AlreadyFile.Emplace(FilePath, true);

			FString FileRef;
			if (!DataTableGetObjectPath(FilePath, FileRef))
			{
				continue;
			}

			// 读取文件内容
			UDataTable* UserInfoDataTable = LoadObject<UDataTable>(nullptr, *FileRef);

			// 保存到指定文件中
			if (UserInfoDataTable)
			{
				// UE_LOG(LogTemp, Warning, TEXT("DataTable To Json.%s"), FileRef);
				FString JsonString = UserInfoDataTable->GetTableAsJSON();
				FString JsonSavePath = FPaths::ProjectContentDir() / TEXT("../TablesServer/" + FileBaseName + ".json");
				FFileHelper::SaveStringToFile(JsonString, *JsonSavePath, FFileHelper::EEncodingOptions::ForceUTF8);
			}
			else
			{
				UE_LOG(LogTemp, Error, TEXT("DataTable To Json. Error %s"), *FileRef);
			}
		}
	}
	return;
}

ObjectPath路径的转换

// 将文件系统路径转换成编辑器的资源路径。没有找到UE4的方法，自己进行了拼接
// 此处逻辑自己对比路径区别
bool EditorModule::DataTableGetObjectPath(FString& FilePath, FString& FileRef)
{
	FString FrontPath = FPaths::GetPath(FilePath);
	int32 Pos = FrontPath.Find(TEXT("/GameData"));

	if (Pos == INDEX_NONE) {
		return false;
	}
	FString MiddlePath = FrontPath.Right(FrontPath.Len() - Pos);

	FString FileBaseName = FPaths::GetBaseFilename(FilePath);
	FileRef = FString::Printf(TEXT("DataTable'/Game%s/%s.%s'"), *MiddlePath, *FileBaseName, *FileBaseName);
	return true;
}

// 文件路径
D:/xxxx/项目/Content/GameData/DT_xxxx.uasset
// 资源路径
“DataTable’/Game/GameData/DT_xxxx.DT_xxxx’”
// 文件路径
D:/xxxx/项目/Content/GameData/tttttt/DT_xxxx.uasset
// 资源路径
“DataTable’/Game/GameData/tttttt/DT_xxxx.DT_xxxx’”