stuff.haml

        = simple_form_for @form, wrapper: :booking do |f|
          .simple-group
            %h3.small-title Your Personal Information
            = f.simple_fields_for :line_items do |li|
              = li.simple_fields_for :passengers do |pax|
                .row
                  .col-md-12
                    %h4= "Trip: #{Product.find(li.object.product_id).title}"
                    %h5= "Tell us about dude ##{pax.index + 1}"
                    = pax.input :first_name, placeholder: 'Big'
                    = pax.input :last_name, placeholder: 'Lebowski'
                    = pax.input :email, placeholder: 'thedude@yourdudeness.com.au'
                    = pax.input :phone_number, placeholder: '+61 410 394 323'
                    = pax.input :dob, label: "Date of birth", placeholder: 'dd/mm/yyyy'
          = f.button :submit

class YourForm < ..
  def product
    Find bla whatever product_id
  end
end

@apotonick doing something like:

class YourForm < Reform::Form
  def product
    Product.find(self.product_id)
  end
end

Will result in getting the following error:

*** ArgumentError Exception: A copy of YourForm has been removed from the module tree but is still active!

Works fine if you do ::Product.find(self.product_id) to jump out of the local scope.

Comments?