Question

How can I read record parameters from the form object (@banner.name)?

= simple_form_for @banner |f|
  = f.name
  ...
  = f.simple_fields_for :params do |o|
    = o.name ????
    = o.created_at ????

Answer 1

Try this way

= simple_form_for @banner |f|
  = f.input :name
  ...
  = f.simple_fields_for :params do |o|
    = o.input :name
    = o.input :created_at, :as => :date

But I’m not sure why you can need an input for created_at. Anyway, the documentation with examples is at their Github page

To just show the value there is an object method

= simple_form_for @banner |f|
  = f.object.name
  ...
  = f.simple_fields_for :params do |o|
    = o.object.name
    = o.object.created_at.strftime('%x %X') # strftime just to format