Question

I have a scenario where users of my ASP.NET web application submit testimonials consisting of text info and images. The submit process has the following steps:

• First the user inputs the content and chooses a path to an image
• When he clicks preview, the info is once again shown so that he can confirm
• Once confirmed the info is persisted in the database

The problem with this is that I don’t want to store uploaded images in the DB before the user actually confirms. Instead I store them as temporary files and put them in DB only after final confirmation.

Since I also want my application to run in medium trust, I have write permissions only to the application directory and nowhere outside. I even want to limit write permissions for the ASPNET / NETWORK SERVICE user to the ~/App_Data folder. The problem with my scenario is that once a temporary file is created in this folder, the application pool is recycled and I don’t want that on every testimonial submit.

How do you advise I keep these temp files instead? The pool is not restarted if I update a file – only on create or rename. But I don’t think I can store whole images in a single file for all users. What do you think?

UPDATE: I should note that I’m using a third party control for upload. It gives me programmatic access to the binary stream of the file contents after upload, but I cannot keep this after a second postback (the first step and postback actually does the upload).

Answer 1

I would recommend IsolatedStorage. It’s a kind of virtual folder.

Here is an excerpt from an example on CodeProject:

IsolatedStorageFileStream stream =    new IsolatedStorageFileStream(ISOLATED_FILE_NAME,    FileMode.Create, isoStore);  StreamWriter writer = new StreamWriter( stream ); writer.WriteLine( 'This is my first line in the isolated storage file.' ); writer.WriteLine( 'This is second line.' ); writer.Close(); 

UPDATE: To clean up your file just do this:

string fileName = 'isolatestorage.txt';  IsolatedStorageFile storage = IsolatedStorageFile.GetStore(     IsolatedStorageScope.User | IsolatedStorageScope.Assembly, null, null);  string[] files = storage.GetFileNames(fileName); foreach(string file in files) {     if(file == fileName) {         storage.DeleteFile(file);         break;     } }