README.md

About this project

A simple file browser written in ASP.NET Core using MVC architecture and sessions.

How it works

In the readme the methods is slightly simplified for general understanding!

The process of interaction with the application will look like this:

1. First, the user uploads a zip file to a special form. Before unzip a project, check if user have upload data beforу.

   We do this to create a new Id (if the user has already upload), because the main Tree method, which displays the files on the site, uses the ResponseCache attribute. If we use the old Id, the Tree method will redirect us to the old files.

   Next we need to load the unzipped data into a hash table (e.g. folder names, file names, paths, etc.) and delete files from the server.

   Why do we need to remove them from the server? Because each client's files will take up a lot of space, and it is quite problematic to delete them after the session is over.

   Methods AddToSessionStorage and ClearFolder you can see in detail in the code.

    // The methods is slightly simplified for general understanding.
    public async Task<IActionResult> Upload(IndexModel im)
    {
        if (im.File != null)
        {
            await HttpContext.Session.LoadAsync();
   
            var _userPath = Path.Combine(_path, GetSessionId());
            var temp = GetSessionId();
   
            if (HttpContext.Session.TryGetValue(temp, out _))
            {
                HttpContext.Session.Clear();
   
                temp = Guid.NewGuid().ToString();
   
                HttpContext.Session.SetString("Id", temp);
   
                _logger.LogInformation("Create new id: " + temp);
   
                _userPath = _userPath.Remove(_userPath.Length - 36) + temp;
            }
   
            Directory.CreateDirectory(_userPath);
   
            string zipPath = Path.Combine(_userPath, im.File.FileName);
   
            using (var fileStream = new FileStream(zipPath, FileMode.Create))
            {
                await im.File.CopyToAsync(fileStream);
            }
   
            ZipFile.ExtractToDirectory(zipPath, _userPath, 
                // https://stackoverflow.com/questions/32402791/unzipping-with-extracttodirectory-method-distorts-non-latin-symbols
                entryNameEncoding:
                Encoding.GetEncoding(System.Globalization.CultureInfo.CurrentCulture.TextInfo.OEMCodePage));
   
            System.IO.File.Delete(zipPath);
            AddToSessionStorage(temp);
            ClearFolder(_userPath);
            Directory.Delete(_userPath);
   
            await HttpContext.Session.CommitAsync();
   
            return RedirectToAction("tree", new { path = temp });
        }
   
        return RedirectToAction("index");
    }

2. If all went well, we move on to the Tree method. It's pretty straightforward.

    [ResponseCache(Location = ResponseCacheLocation.Client, Duration = 60 * 10)]
    public async Task<IActionResult> Tree(string path)
    {
        await HttpContext.Session.LoadAsync();
   
        string? value = HttpContext.Session.GetString(path);
   
        if (string.IsNullOrEmpty(value))
        {
            _logger.LogWarning("Incorrect session!");
            return RedirectToAction(nameof(Index));
        }
   
        return View(JsonSerializer.Deserialize<FilesInfo>(value));
    }