<%= simple_form_for @object, url: @form_action_url, method: :post do |f| %> <% @generic_form_fields.each do |name| %> <%= f.input name %> <% end %> <%= f.input :_position, as: :hidden if @object.class.fields.keys.include? '_position' %> <%= f.input :hidden, as: :hidden if @object.class.fields.keys.include? 'hidden' %> <% end %>