Flash uploader and ASP.net MVC

Question

I have a flash upload component I want to use to upload multiple files. I'm using it in a MVC app and what I want to happen is that the user picks the files they want to upload, it uploads them and then displays a page showing all the files they have uploaded so they can add a description and select where to save them, and then save the files.

At the moment when files are uploaded the flash component calls a controller to process the files, this bit works fine, I can get the uploaded files and do what I like with them. The problem is is that I cannot just redirect to a View once the controllers done its work, because its the flash component calling the controller, not the page and so nothing happens when you try and do that.

I had attempted to save the files in the session and then forward the user on completion of the upload using some code in the flash actionscript, this however does not work, the session always turns up null. I had also considered actually saving the files to a temp location and then on the displaying page just listing all files in the temp location, but this is then going to involve saving the files twice, once to the temp directory and then to the actual place the user wants to put them, which I assume will be slow.

Any thoughts on the best way to do this?

Answer 1

Is your site using cookie based authentication? If so then the flash uploader needs to include the authentication cookie when uploading otherwise the upload will be seen as coming from a new user - this would explain your null values in the session state. If you are unable to get flash to post the cookie then you'll have to identify the user within the upload URL.

You should keep session state to a minimum or even better not use is at all so storing large amounts of data such as images in it is a bad idea.

With our applications we save all uploaded files to the database and then give them a unique Guid that is then used to retrieved/display them later. Within the database images could be associated with a user and in your case be marked as just uploaded so that when you redirect the user to the additional information page you know which images to display.

but this is then going to involve saving the files twice, once to the temp directory and then to the actual place the user wants to put them

In relation to where the files are saved on the server you should not be allowing the user to determine where the files are saved.