Abstracting a form

If you wanted to abstract or wrap a form in Rails, how would you do
it?

The purpose of this is to capture form-specific behavior--
preprocessing, basically--that doesn't belong in a model.

Django, for example, works at this level:

http://docs.djangoproject.com/en/1.2/topics/forms/

Maybe a controller filter or private method would accomplish this, but
I don't want to make the controller "fat."

djangst wrote in post #977614:

If you wanted to abstract or wrap a form in Rails, how would you do
it?

What do you mean?

The purpose of this is to capture form-specific behavior--
preprocessing, basically--that doesn't belong in a model.

Do you have a concrete example in mind?

Django, for example, works at this level:

http://docs.djangoproject.com/en/1.2/topics/forms/

Maybe a controller filter or private method would accomplish this, but
I don't want to make the controller "fat."

In all likelihood, you want another model -- or maybe a presenter. But
it's hard to say for sure until you describe the actual problem you're
trying to solve.

Best,