How to set up form for a hash in Rails?

Question

I have some data associated with a model that is in a hash. The hash is generated in the controller: @hash.

What is the proper way to create a form for this

Answer 1

When you use the helpers that end with _tag that's what happens.

Instead of text_field_tag ... use f.text_field ....

In order to get a hash like params => {:hash => {:field1 => "", :field2 => ""}} you have to pair up form_for with f.input_field_type instead of simply input_field_tag.

See the difference?