IFolder Interface

public interface IFolder : IFileSystemItem

Public Interface IFolder
	Inherits IFileSystemItem

public interface class IFolder : IFileSystemItem

type IFolder =  
    interface
        interface IFileSystemItem
    end

public class VirtualFolder : VirtualFileSystemItem, IFolder
{
    public VirtualFolder(IMapping mapping, string path, ILogger logger) : base(mapping, path, logger)
    {

    }

    public async Task<IFileMetadata> CreateFileAsync(IFileMetadata metadata, Stream content = null, IOperationContext operationContext = null, IInSyncResultContext inSyncResultContext = null, CancellationToken cancellationToken = default)
    {
        string userFileSystemNewItemPath = Path.Combine(UserFileSystemPath, metadata.Name);
        Logger.LogMessage($"{nameof(IFolder)}.{nameof(CreateFileAsync)}()", userFileSystemNewItemPath, default, operationContext, metadata);

        FileInfo remoteStorageNewItem = new FileInfo(Path.Combine(RemoteStoragePath, metadata.Name));

        // Create remote storage file.
        using (FileStream remoteStorageStream = remoteStorageNewItem.Open(FileMode.CreateNew, FileAccess.Write, FileShare.Delete))
        {
            // Upload content. Note that if the file is blocked - content parameter is null.
            if (content != null)
            {
                try
                {
                    await content.CopyToAsync(remoteStorageStream);
                }
                catch (OperationCanceledException)
                {
                    // Operation was canceled by the calling Engine.StopAsync() or the operation timeout occurred.
                    Logger.LogMessage($"{nameof(IFolder)}.{nameof(CreateFileAsync)}() canceled", userFileSystemNewItemPath, default, operationContext, metadata);
                }
                remoteStorageStream.SetLength(content.Length);
            }
        }

        // Update remote storage file metadata.
        remoteStorageNewItem.Attributes = metadata.Attributes.Value & ~FileAttributes.ReadOnly;
        remoteStorageNewItem.CreationTimeUtc = metadata.CreationTime.Value.UtcDateTime;
        remoteStorageNewItem.LastWriteTimeUtc = metadata.LastWriteTime.Value.UtcDateTime;
        remoteStorageNewItem.LastAccessTimeUtc = metadata.LastAccessTime.Value.UtcDateTime;
        remoteStorageNewItem.Attributes = metadata.Attributes.Value;

        // Typically you must return IFileMetadata with a remote storage item ID, content eTag and metadata eTag.
        // The ID will be passed later into IEngine.GetFileSystemItemAsync() method.
        // However, becuse we can not read the ID for the network path we return null.
        return null; 
    }

    public async Task<IFolderMetadata> CreateFolderAsync(IFolderMetadata metadata, IOperationContext operationContext, IInSyncResultContext inSyncResultContext, CancellationToken cancellationToken = default)
    {
        string userFileSystemNewItemPath = Path.Combine(UserFileSystemPath, metadata.Name);
        Logger.LogMessage($"{nameof(IFolder)}.{nameof(CreateFolderAsync)}()", userFileSystemNewItemPath, default, operationContext, metadata);

        DirectoryInfo remoteStorageNewItem = new DirectoryInfo(Path.Combine(RemoteStoragePath, metadata.Name));
        remoteStorageNewItem.Create();

        // Update remote storage folder metadata.
        remoteStorageNewItem.Attributes = metadata.Attributes.Value & ~FileAttributes.ReadOnly;
        remoteStorageNewItem.CreationTimeUtc = metadata.CreationTime.Value.UtcDateTime;
        remoteStorageNewItem.LastWriteTimeUtc = metadata.LastWriteTime.Value.UtcDateTime;
        remoteStorageNewItem.LastAccessTimeUtc = metadata.LastAccessTime.Value.UtcDateTime;
        remoteStorageNewItem.Attributes = metadata.Attributes.Value;

        // Typically you must return IFileMetadata with a remote storage item ID and metadata eTag.
        // The ID will be passed later into IEngine.GetFileSystemItemAsync() method.
        // However, becuse we can not read the ID for the network path we return null.
        return null;
    }

    public async Task GetChildrenAsync(string pattern, IOperationContext operationContext, IFolderListingResultContext resultContext, CancellationToken cancellationToken)
    {
        // This method has a 60 sec timeout. 
        // To process longer requests and reset the timeout timer call one of the following:
        // - resultContext.ReturnChildren() method.
        // - resultContext.ReportProgress() method.

        Logger.LogMessage($"{nameof(IFolder)}.{nameof(GetChildrenAsync)}({pattern})", UserFileSystemPath, default, operationContext);

        List<IFileSystemItemMetadata> children = new List<IFileSystemItemMetadata>();
        IEnumerable<FileSystemInfo> remoteStorageChildren = new DirectoryInfo(RemoteStoragePath).EnumerateFileSystemInfos(pattern);

        foreach (FileSystemInfo remoteStorageItem in remoteStorageChildren)
        {
            IFileSystemItemMetadata itemInfo = Mapping.GetUserFileSysteItemMetadata(remoteStorageItem);
            children.Add(itemInfo);
        }

        // To signal that the children enumeration is completed 
        // always call ReturnChildren(), even if the folder is empty.
        await resultContext.ReturnChildrenAsync(children.ToArray(), children.Count(), true, cancellationToken);
    }

    public async Task<IFolderMetadata> WriteAsync(IFolderMetadata metadata, IOperationContext operationContext, IInSyncResultContext inSyncResultContext, CancellationToken cancellationToken = default)
    {
        Logger.LogMessage($"{nameof(IFolder)}.{nameof(WriteAsync)}()", UserFileSystemPath, default, operationContext, metadata);

        DirectoryInfo remoteStorageItem = new DirectoryInfo(RemoteStoragePath);

        // Update remote storage folder metadata.
        if (metadata.Attributes.HasValue)
        {
            remoteStorageItem.Attributes = metadata.Attributes.Value & ~FileAttributes.ReadOnly;
        }

        if (metadata.CreationTime.HasValue)
        {
            remoteStorageItem.CreationTimeUtc = metadata.CreationTime.Value.UtcDateTime;
        }

        if (metadata.LastWriteTime.HasValue)
        {
            remoteStorageItem.LastWriteTimeUtc = metadata.LastWriteTime.Value.UtcDateTime;
        }

        if (metadata.LastAccessTime.HasValue)
        {
            remoteStorageItem.LastAccessTimeUtc = metadata.LastAccessTime.Value.UtcDateTime;
        }

        if (metadata.Attributes.HasValue)
        {
            remoteStorageItem.Attributes = metadata.Attributes.Value;
        }

        return null;
    }
}