Rails3 generating and streaming large files

Question

Hello, my Rails3 Application has a certain request which generates a large CSV (20mb+) on the fly, and then prompts the user to download the file (while it is being generated).

I've noticed while upgrading from Rails 2.3.x using "render :text => proc" no longer works. I am now working on a solution that will let me keep things working in a similar fashion.

The fact that the file is being generated on the fly has not caused any pain just yet. Only certain users, can access this feature (think monthly reports, etc).

I am basically planning on two different approaches, 1. add a custom renderer which will let me use a proc again 2. generate the file in a thread, and use "send_data" to try and stream the file as it is being generated.

I haven't implemented yet, so if anyone can provide some insight, it may help clear things up as the code is upgraded.

Thanks!!!