public static async Task <bool> FolderExists(this StorageFolder folder, string folderPath)
{
if (String.IsNullOrEmpty(folderPath))
{
return(true);
}
var firstPart = Paths.RootFolderName(folderPath);
if (await folder.ContainsFolderAsync(firstPart))
{
var subFolder = await folder.GetFolderAsync(firstPart);
var tail = Paths.DropRoot(folderPath, firstPart);
return(await subFolder.FolderExists(tail));
}
else
{
return(false);
}
}
/// <summary>
/// FP in C#.
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="folder"></param>
/// <param name="filePath"></param>
/// <param name="filesCombinator"></param>
/// <param name="notFound"></param>
/// <returns></returns>
private static async Task <T> InspectFilePath <T>(this StorageFolder folder, string filePath, Func <IReadOnlyList <StorageFile>, Func <Func <StorageFile, bool>, T> > filesCombinator, T notFound = default(T))
{
var fileName = Paths.FileNameOf(filePath);
var firstPart = Paths.RootFolderName(filePath);
if (firstPart == fileName)
{
var files = (await folder.GetFilesAsync());
return(filesCombinator(files)(file => file.Name == fileName));
}
if (await folder.ContainsFolderAsync(firstPart))
{
var subFolder = await folder.GetFolderAsync(firstPart);
var tail = Paths.DropRoot(filePath, firstPart);
return(await subFolder.InspectFilePath(tail, filesCombinator, notFound));
}
else
{
return(notFound);
}
}