C# newbie problem part 2 - declaring class and method

Question

[AcceptVerbs(HttpVerbs.Post)]
public ActionResult Upload(Photo photo)
{
    foreach (string file in Request.Files)
    {

        var path = "~/Uploads/Photos/";

        HttpPostedFileBase posted = (HttpPostedFileBase)Request.Files[file];

        if (posted.ContentLength > 0)
        {
            photo.Date = DateTime.Now;
            photo.AlbumID = 1;
            photo.Title = Path.GetFileName(posted.FileName);

            photoRepository.Add(photo);
            photoRepository.Save();

            posted.SaveAs(Server.MapPath(path + photo.PhotoID + ".jpg"));

            Image img1 = Image.FromFile(Server.MapPath("~/Uploads/Photos/") + photo.PhotoID + ".jpg");

            imageHelper.CreateThumbnail(posted, img1);

            int newWidth = 100;
            int newHeight = 100;
            double ratio = 0;

            if (img1.Width > img1.Height)
            {
                ratio = img1.Width / (double)img1.Height;
                newHeight = (int)(newHeight / ratio);
            }
            else
            {
                ratio = img1.Height / (double)img1.Width;
                newWidth = (int)(newWidth / ratio);
            }

            Image bmp1 = img1.GetThumbnailImage(newWidth, newHeight, null, IntPtr.Zero);
            bmp1.Save(Server.MapPath("~/Uploads/Photos/Thumbnails/") + photo.PhotoID + ".jpg");

            img1.Dispose();
            bmp1.Dispose();
        }
    }

    return RedirectToAction("Index");
}

I would like to organize this code a little better, something like this:

[AcceptVerbs(HttpVerbs.Post)]
public ActionResult Upload(Photo photo)
{
    foreach (string file in Request.Files)
    {

        var path = "~/Uploads/Photos/";

        HttpPostedFileBase posted = (HttpPostedFileBase)Request.Files[file];
        ImageHelper imageHelper = new ImageHelper();  

        if (posted.ContentLength > 0)
        {
            photo.Date = DateTime.Now;
            photo.AlbumID = 1;
            photo.Title = Path.GetFileName(posted.FileName);

            photoRepository.Add(photo);
            photoRepository.Save();

            posted.SaveAs(Server.MapPath(path + photo.PhotoID + ".jpg"));

            Image img1 = Image.FromFile(Server.MapPath("~/Uploads/Photos/") + photo.PhotoID + ".jpg");

            // Create thumbnail
            imageHelper.CreateThumbnail(posted, img1);                    
        }
    }

    return RedirectToAction("Index");
}

and here, in Helpers folder I created class and method that will deal with thumbnail:

public class ImageHelper
{        
    public void CreateThumbnail(HttpPostedFileBase posted, Image img1)
    {
        int newWidth = 100;
        int newHeight = 100;
        double ratio = 0;

        if (img1.Width > img1.Height)
        {
            ratio = img1.Width / (double)img1.Height;
            newHeight = (int)(newHeight / ratio);
        }
        else
        {
            ratio = img1.Height / (double)img1.Width;
            newWidth = (int)(newWidth / ratio);
        }

        Image bmp1 = img1.GetThumbnailImage(newWidth, newHeight, null, IntPtr.Zero);
        bmp1.Save(Server.MapPath("~/Uploads/Photos/Thumbnails/") + photo.PhotoID + ".jpg");

        img1.Dispose();
        bmp1.Dispose();
    } 
}

But I get compile error that Server (in ImageHelper class in bmp1.Save(Server.MapPath... line) doesn't exist in the current context, while it works fine if code is in one place.
What am I doing wrong and is this even proper way of declaring method and organizing code?

Thanks in advance,
Ile

Answer 1

Server is a property of the Controller class. This is why it's accessible in Update action. In order to use it from the outside, you can get ahold of it via HttpContext.Current.Server.

This, however, will make your code less testable and more tightly coupled with ASP.NET specifics. Rather, rewrite this method so that it will be independent of any of ASP.NET-related stuff.

In this particular case, you can add additional argument to the method, which would tell it where to save thumbnails:

void CreateThumbnail(Image img1, string targetDirectory)

Answer 2

Instead of having your CreateThumbnail method directly call things off of "Server", instead you should pass those resources into your function. This allows for better separation of concerns and, ultimately, better reusability. Additionally, it will correct your problem as well.