error.rb

Started GET "/" for 127.0.0.1 at 2016-07-11 00:13:57 +0300
  ActiveRecord::SchemaMigration Load (0.5ms)  SELECT "schema_migrations".* FROM "schema_migrations"
Processing by Refinery::PagesController#home as HTML
  Parameters: {"locale"=>:pt}
  Refinery::Page Load (0.7ms)  SELECT  "refinery_pages".* FROM "refinery_pages" WHERE "refinery_pages"."link_url" = $1 LIMIT 1  [["link_url", "/"]]
  Refinery::Banners::Banner Load (0.5ms)  SELECT "refinery_banners".* FROM "refinery_banners"
  CACHE (0.0ms)  SELECT "refinery_banners".* FROM "refinery_banners"
  Refinery::Posts::Post Load (0.4ms)  SELECT "refinery_posts".* FROM "refinery_posts"
  CACHE (0.0ms)  SELECT "refinery_posts".* FROM "refinery_posts"
  Refinery::Image Load (0.4ms)  SELECT  "refinery_images".* FROM "refinery_images" WHERE "refinery_images"."id" = $1 LIMIT 1  [["id", 1]]
  Refinery::Banners::Banner::Translation Load (0.4ms)  SELECT "refinery_banner_translations".* FROM "refinery_banner_translations" WHERE "refinery_banner_translations"."refinery_banner_id" = $1  [["refinery_banner_id", 1]]
  Rendered refinery/pages/_availability_form.html.erb (9.6ms)
  Rendered refinery/pages/home.html.erb within layouts/application (95.8ms)
Completed 500 Internal Server Error in 339ms (ActiveRecord: 10.9ms)

ActionView::Template::Error (First argument in form cannot contain nil or be empty):
    1: 
    2:     <%= form_for [refinery, :booking_requests, @booking_request] do |f| %>
    3:       <%= render '/refinery/admin/error_messages',
    4:                  :object => @booking_request,
    5:                  :include_object_name => true  %>
  app/views/refinery/pages/_availability_form.html.erb:2:in `_app_views_refinery_pages__availability_form_html_erb___1076700293952781979_70128677673340'
  app/views/refinery/pages/home.html.erb:19:in `_app_views_refinery_pages_home_html_erb___106980178210980587_70128699167140'


  Rendered /Users/karina/.rbenv/versions/2.2.3/lib/ruby/gems/2.2.0/gems/actionpack-4.2.6/lib/action_dispatch/middleware/templates/rescues/_source.erb (10.9ms)
  Rendered /Users/karina/.rbenv/versions/2.2.3/lib/ruby/gems/2.2.0/gems/actionpack-4.2.6/lib/action_dispatch/middleware/templates/rescues/_trace.html.erb (4.9ms)
  Rendered /Users/karina/.rbenv/versions/2.2.3/lib/ruby/gems/2.2.0/gems/actionpack-4.2.6/lib/action_dispatch/middleware/templates/rescues/_request_and_response.html.erb (1.1ms)
  Rendered /Users/karina/.rbenv/versions/2.2.3/lib/ruby/gems/2.2.0/gems/actionpack-4.2.6/lib/action_dispatch/middleware/templates/rescues/template_error.html.erb within rescues/layout (93.0ms)
  Rendered /Users/karina/.rbenv/versions/2.2.3/lib/ruby/gems/2.2.0/gems/web-console-2.3.0/lib/web_console/templates/_markup.html.erb (0.6ms)
  Rendered /Users/karina/.rbenv/versions/2.2.3/lib/ruby/gems/2.2.0/gems/web-console-2.3.0/lib/web_console/templates/_inner_console_markup.html.erb within layouts/inlined_string (0.4ms)
  Rendered /Users/karina/.rbenv/versions/2.2.3/lib/ruby/gems/2.2.0/gems/web-console-2.3.0/lib/web_console/templates/_prompt_box_markup.html.erb within layouts/inlined_string (0.5ms)
  Rendered /Users/karina/.rbenv/versions/2.2.3/lib/ruby/gems/2.2.0/gems/web-console-2.3.0/lib/web_console/templates/style.css.erb within layouts/inlined_string (0.4ms)
  Rendered /Users/karina/.rbenv/versions/2.2.3/lib/ruby/gems/2.2.0/gems/web-console-2.3.0/lib/web_console/templates/console.js.erb within layouts/javascript (81.6ms)
  Rendered /Users/karina/.rbenv/versions/2.2.3/lib/ruby/gems/2.2.0/gems/web-console-2.3.0/lib/web_console/templates/main.js.erb within layouts/javascript (0.3ms)
  Rendered /Users/karina/.rbenv/versions/2.2.3/lib/ruby/gems/2.2.0/gems/web-console-2.3.0/lib/web_console/templates/error_page.js.erb within layouts/javascript (0.4ms)
  Rendered /Users/karina/.rbenv/versions/2.2.3/lib/ruby/gems/2.2.0/gems/web-console-2.3.0/lib/web_console/templates/index.html.erb (174.6ms)

form.html.erb

    <%= form_for [refinery, :booking_requests, @booking_request] do |f| %>
      <%= render '/refinery/admin/error_messages',
                 :object => @booking_request,
                 :include_object_name => true  %>

      <div class='field brfrom_field date_field'>
        <%= f.label :brfrom %>
        <%= f.date_select :brfrom %>
      </div>

      <div class='field brto_field date_field'>
        <%= f.label :brto %>
        <%= f.date_select :brto %>
      </div>

      <div class='field unit_id_field integer_field'>
        <%= f.label :unit_id %>
      </div>

      <div class='field customer_id_field integer_field'>
        <%= f.label :customer_id %>
      </div>

      <div class='field status_field string_field'>
        <%= f.label :status %>
        <%= f.text_field :status %>
      </div>

      <div class='actions'>
        <%= f.submit t('.send') %>
      </div>
    <% end %>

pages_controller_decorator.rb

Refinery::PagesController.class_eval do


    ...
    before_filter :build_booking_request

    private

      def build_booking_request
        @subscription = Refinery::BookingRequests::BookingRequest.new
      end



end