Rails 3 multi-step form with file upload

I having some trouble trying to figure out how to implement a Rails 3 multi-page form with file uploads, where each step is handled by the update/edit actions in the controller.

Ryan Bates provided his wonderful screencast for how to to do multi-step forms using sessions, as well as a brief description on how to accomplish something similar by saving to the database on the initial step and then perform updates on each successive step. I have also read his gist giving a more detailed explanation of some different options on how to create a multi-step form (I am leaning toward option 1).

But I am still quite a bit lost when it comes to the actual implementation of a multi-step form. My goal is to use carrierwave for the file uploads (images), and perhaps workflow by geekq for the state machine to help with with validations at each step.

Just to be clear, I am currently trying to create an entry in the database on the initial step of the wizard, and have each successive page update the model.

Any ideas?

An example or a point in the right direction would be greatly appreciated.

Thanks!

Note: I have read another post where they mention something about a key/value data-store, but that unfortunately is a bit over my head...

Key-Value store or SQL for that matter are very loosely tied to your actual problem. Those are just a different approaches on how your data are actually stored in the backend. Using one way or another doesn't really make a difference in your case.

As for the actual question I think its too general for SO. Multistep forms tend to be very different one from another. There is no "one good way" of doing those.

The reason you are not getting any answers on this is probably because there is no real question asked. What you should do is to try to do actual implementation and post more specific questions when hitting the wall somewhere.

In the end - I believe the multistep forms are not really the best idea when it comes to usability. Of course there are valid reasons to use them in some cases, but you should really think twice if there is a way to avoid those in your case.

One of the problems I had while ago with forms and uploads was the validation (It isn't related to Multi/Single step specifically). Normally when validation fails user would have to re-upload the file. Fortunately in your case this not much of an issue, since Carrierwave handles that automatically.