How do I manage ajax uploads using SWF Upload for concurrent users?

I'm building a simple email functionality in my web application and would like to set it up to be able to send in attachments as well. The thing is that I want to set up the ability to upload files i.e attachemnts asynchronously. I'd like to use SWFUpload for this however 'ajax' uploaders upload the file to a location on the server - that location is m开发者_JS百科ost often prearranged in code or in a config file. In this case I don't want to end up with a situation where concurrent users are uploading files onto this temporary area and they overwrite each other.

How do I set it up. I'm using php MYSQL and the prototype javascript library here.

In this case I don't want to end up with a situation where concurrent users are uploading files onto this temporary area and they overwrite each other.

A good way to avoid this is to generate a random key before the upload process starts, and to prefix every uploaded file with that random key.

When it is time to send the E-Mail, you fetch all the files with that random key.

You could alternatively also create a temporary directory named after the random key, and store all the files there.

That way, you avoid collisions between users and even between multiple upload processes from the same user.