Support for nested forms with custom models

[jasiek]

Let's say you have a parent form, which wants to display a nested form - if your model already has a has_many association declared, reform will discover that and will use a nested form for that association. This is great, but what if you want to use custom models in that nested form?

I've tried the following:

class BuyerForm
  collection :rates, form: RateForm
end

class RateForm
  model CurrentRate
end

but that will just populate the rates collection with RateForms whose models will be instances of Rate rather than CurrentRate.

In any case, I've come up with this, which I think mostly achieves what I wanted to achieve. I feel however that it should be possible to define what model the child form should use via a call to model.

Have a look at this repository: https://github.com/jasiek/evil_twin/commit/b36290b98fa5645cc5f0c54b6f4d434f396e8d1d