Форма remote => true возвращает html вместо js при использовании carrierwave

Я новичок в рельсах, и я столкнулся с некоторыми трудностями, когда пытался загрузить файл с помощью несущей с помощью Ajax. Ниже приведено кодирование:

composition.rb

class Composition < ApplicationRecord
 belongs_to :question_paper
 mount_uploader :image_path, ImageUploader

 validates :question_title, presence: true
 validates :topic, presence: true
 validates :image_path, presence: true  
end

question_paper_generations_controller.rb

def composition
 @composition = Composition.new

 respond_to do |format|
   format.js
 end
end

def composition_create
  @teacher = current_teacher
  @question_paper = @teacher.question_papers

  comp_prms = composition_params

  if comp_prms[:guided] == "Guided"
    comp_prms[:guided] = true
  else
    comp_prms[:guided] = false
  end

  comp_prms[:lvl_of_difficulty] = params[:composition][:lvl_of_difficulty][0].to_i

  @composition = @question_paper.last.compositions.new(comp_prms)

  respond_to do |format|
    if @composition.save
      if params[:composition][:guided] == "Guided"
        format.js { render :action => "comp_guided" }
      elsif params[:composition][:guided] == "Not Guided"
        format.js { render :action => "comp_not_guided" }
      end
    else
      render 'composition'
    end
  end
end

composition.html.erb

<%= form_for(@composition, url: composition_path, remote: true) do |f| %>

  <%= render 'shared/composition_error_messages' %>

  <%= f.label :question_title %>
  <%= f.text_field :question_title, class: 'form-control' %>

  <%= f.label :guided %>
  <%= f.select :guided, options_for_select([['Guided'], ['Not Guided']]), {}, { class: 'form-control'} %>

  <%= f.label :topic %>
  <%= f.text_field :topic, class: 'form-control' %>

  <%= f.label :level_of_difficulty %>
  <%= f.select :lvl_of_difficulty, options_for_select([['1 - Easy'], ['2 - Moderate'], ['3 - Hard']]), {}, { class: 'form-control'} %>

  <%= f.label :composition_image %>
  <%= f.file_field :image_path, class: 'form-control' %>

  <%= f.submit "Save and Continue", class: "btn btn-primary", :remote => true %>
<% end %>

Прежде всего, я получаю ошибку 406, когда пытался отправить форму. Я исправляю, добавляя в форму hidden_tag <%= hidden_field_tag :authenticity_token, form_authenticity_token %> в форме, чтобы включить токен аутентификации. Форма отправлена успешно, но она была отправлена как HTML, а не JS, и это не то, что я хочу, потому что мне нужно отправить ее через Ajax и выполнить javascript после отправки формы.

Перед добавлением <%= hidden_field_tag :authenticity_token, form_authenticity_token %>

rails server log

Started POST "/composition" for 127.0.0.1 at 2018-03-12 09:34:38 +0800
Processing by QuestionPaperGenerationsController#composition_create as HTML
Parameters: {"utf8"=>"✓", "composition"=>{"question_title"=>"你好", 
"guided"=>"Guided", "topic"=>"你好", "lvl_of_difficulty"=>"1 - Easy", 
"image_path"=>#<ActionDispatch::Http::UploadedFile:0xc509850 @tempfile=#
<Tempfile:C:/Users/weiki/AppData/Local/Temp/RackMultipart20180312-4592-
19d63mw.jpg>, @original_filename="bg.jpg", @content_type="image/jpeg", 
@headers="Content-Disposition: form-data; name=\"composition[image_path]\"; 
filename=\"bg.jpg\"\r\nContent-Type: image/jpeg\r\n">}, "commit"=>"Save and 
Continue"}
Can't verify CSRF token authenticity.
Completed 422 Unprocessable Entity in 2ms (ActiveRecord: 0.0ms)



ActionController::InvalidAuthenticityToken 
(ActionController::InvalidAuthenticityToken):

actionpack (5.1.2) 
lib/action_controller/metal/request_forgery_protection.rb:195:in 
'handle_unverified_request'
actionpack (5.1.2) 
lib/action_controller/metal/request_forgery_protection.rb:227:in 
'handle_unverified_request'
actionpack (5.1.2) 
lib/action_controller/metal/request_forgery_protection.rb:222:in 
'verify_authenticity_token'
activesupport (5.1.2) lib/active_support/callbacks.rb:413:in 'block in 
make_lambda'
activesupport (5.1.2) lib/active_support/callbacks.rb:197:in 'block (2 
levels) in halting'
actionpack (5.1.2) lib/abstract_controller/callbacks.rb:12:in 'block (2 
levels) in <module:Callbacks>'
activesupport (5.1.2) lib/active_support/callbacks.rb:198:in 'block in 
halting'
activesupport (5.1.2) lib/active_support/callbacks.rb:507:in 'block in 
invoke_before'
activesupport (5.1.2) lib/active_support/callbacks.rb:507:in 'each'
activesupport (5.1.2) lib/active_support/callbacks.rb:507:in 'invoke_before'
activesupport (5.1.2) lib/active_support/callbacks.rb:130:in 'run_callbacks'
actionpack (5.1.2) lib/abstract_controller/callbacks.rb:19:in 
'process_action'
actionpack (5.1.2) lib/action_controller/metal/rescue.rb:20:in 
'process_action'
actionpack (5.1.2) lib/action_controller/metal/instrumentation.rb:32:in 
'block in process_action'
activesupport (5.1.2) lib/active_support/notifications.rb:166:in 'block in 
instrument'
activesupport (5.1.2) lib/active_support/notifications/instrumenter.rb:21:in 
'instrument'
activesupport (5.1.2) lib/active_support/notifications.rb:166:in 
'instrument'
actionpack (5.1.2) lib/action_controller/metal/instrumentation.rb:30:in 
'process_action'
actionpack (5.1.2) lib/action_controller/metal/params_wrapper.rb:252:in 
'process_action'
 activerecord (5.1.2) lib/active_record/railties/controller_runtime.rb:22:in 
'process_action'
actionpack (5.1.2) lib/abstract_controller/base.rb:124:in 'process'
actionview (5.1.2) lib/action_view/rendering.rb:30:in 'process'
actionpack (5.1.2) lib/action_controller/metal.rb:189:in 'dispatch'
actionpack (5.1.2) lib/action_controller/metal.rb:253:in 'dispatch'
actionpack (5.1.2) lib/action_dispatch/routing/route_set.rb:49:in 'dispatch'
actionpack (5.1.2) lib/action_dispatch/routing/route_set.rb:31:in 'serve'
actionpack (5.1.2) lib/action_dispatch/journey/router.rb:46:in 'block in 
serve'
actionpack (5.1.2) lib/action_dispatch/journey/router.rb:33:in 'each'
actionpack (5.1.2) lib/action_dispatch/journey/router.rb:33:in 'serve'
actionpack (5.1.2) lib/action_dispatch/routing/route_set.rb:832:in 'call'
remotipart (1.3.1) lib/remotipart/middleware.rb:32:in 'call'
rack (2.0.3) lib/rack/etag.rb:25:in 'call'
rack (2.0.3) lib/rack/conditional_get.rb:38:in 'call'
rack (2.0.3) lib/rack/head.rb:12:in 'call'
rack (2.0.3) lib/rack/session/abstract/id.rb:232:in 'context'
rack (2.0.3) lib/rack/session/abstract/id.rb:226:in 'call'
actionpack (5.1.2) lib/action_dispatch/middleware/cookies.rb:613:in 'call'
activerecord (5.1.2) lib/active_record/migration.rb:556:in 'call'
actionpack (5.1.2) lib/action_dispatch/middleware/callbacks.rb:26:in 'block 
in call'
activesupport (5.1.2) lib/active_support/callbacks.rb:97:in 'run_callbacks'
actionpack (5.1.2) lib/action_dispatch/middleware/callbacks.rb:24:in 'call'
actionpack (5.1.2) lib/action_dispatch/middleware/executor.rb:12:in 'call'
actionpack (5.1.2) lib/action_dispatch/middleware/debug_exceptions.rb:59:in 
'call'
web-console (3.5.1) lib/web_console/middleware.rb:135:in 'call_app'
web-console (3.5.1) lib/web_console/middleware.rb:28:in 'block in call'
web-console (3.5.1) lib/web_console/middleware.rb:18:in 'catch'
web-console (3.5.1) lib/web_console/middleware.rb:18:in 'call'
actionpack (5.1.2) lib/action_dispatch/middleware/show_exceptions.rb:31:in 
'call'
railties (5.1.2) lib/rails/rack/logger.rb:36:in 'call_app'
railties (5.1.2) lib/rails/rack/logger.rb:24:in 'block in call'
activesupport (5.1.2) lib/active_support/tagged_logging.rb:69:in 'block in 
tagged'
activesupport (5.1.2) lib/active_support/tagged_logging.rb:26:in 'tagged'
activesupport (5.1.2) lib/active_support/tagged_logging.rb:69:in 'tagged'
railties (5.1.2) lib/rails/rack/logger.rb:24:in 'call'
sprockets-rails (3.2.1) lib/sprockets/rails/quiet_assets.rb:13:in 'call'
actionpack (5.1.2) lib/action_dispatch/middleware/remote_ip.rb:79:in 'call'
actionpack (5.1.2) lib/action_dispatch/middleware/request_id.rb:25:in 'call'
rack (2.0.3) lib/rack/method_override.rb:22:in 'call'
rack (2.0.3) lib/rack/runtime.rb:22:in 'call'
activesupport (5.1.2) 
lib/active_support/cache/strategy/local_cache_middleware.rb:27:in 'call'
actionpack (5.1.2) lib/action_dispatch/middleware/executor.rb:12:in 'call'
actionpack (5.1.2) lib/action_dispatch/middleware/static.rb:125:in 'call'
rack (2.0.3) lib/rack/sendfile.rb:111:in 'call'
railties (5.1.2) lib/rails/engine.rb:522:in 'call'
puma (3.9.1) lib/puma/configuration.rb:224:in 'call'
puma (3.9.1) lib/puma/server.rb:602:in 'handle_request'
puma (3.9.1) lib/puma/server.rb:435:in 'process_client'
puma (3.9.1) lib/puma/server.rb:299:in 'block in run'
puma (3.9.1) lib/puma/thread_pool.rb:120:in 'block in spawn_thread'

После добавления <%= hidden_field_tag :authenticity_token, form_authenticity_token %>

rails server log

Started POST "/composition" for 127.0.0.1 at 2018-03-12 09:42:30 +0800
Processing by QuestionPaperGenerationsController#composition_create as HTML
Parameters: {"utf8"=>"✓", "authenticity_token"=>"u+xjkaGZ3KQ4WRxYfbhsV7+tPsuhtaKDmLvo1ToLG5+DUgHbeWqtsgsy9ogJRQGinXTAYQQ2ge1CKViyJFPtAg==", "composition"=>{"question_title"=>"你好", "guided"=>"Guided", "topic"=>"你好", "lvl_of_difficulty"=>"1 - Easy", "image_path"=>#<ActionDispatch::Http::UploadedFile:0xdf30b18 @tempfile=#<Tempfile:C:/Users/weiki/AppData/Local/Temp/RackMultipart20180312-4592-fio4v3.jpg>, @original_filename="72030c760581fc40475a604dbb55bbb7.jpg", @content_type="image/jpeg", @headers="Content-Disposition: form-data; name=\"composition[image_path]\"; filename=\"72030c760581fc40475a604dbb55bbb7.jpg\"\r\nContent-Type: image/jpeg\r\n">}, "commit"=>"Save and Continue"}
Teacher Load (1.0ms)  SELECT  "teachers".* FROM "teachers" WHERE "teachers"."id" = ? LIMIT ?  [["id", 1], ["LIMIT", 1]]
QuestionPaper Load (0.0ms)  SELECT  "question_papers".* FROM "question_papers" INNER JOIN "question_papers_teachers" ON "question_papers"."id" = "question_papers_teachers"."question_paper_id" WHERE "question_papers_teachers"."teacher_id" = ? ORDER BY "question_papers"."id" DESC LIMIT ?  [["teacher_id", 1], ["LIMIT", 1]]
 (0.0ms)  begin transaction
 SQL (3.0ms)  INSERT INTO "compositions" ("question_title", "image_path", "guided", "lvl_of_difficulty", "topic", "question_paper_id", "created_at", "updated_at") VALUES (?, ?, ?, ?, ?, ?, ?, ?)  [["question_title", "你好"], ["image_path", "72030c760581fc40475a604dbb55bbb7.jpg"], ["guided", "t"], ["lvl_of_difficulty", 1], ["topic", "你好"], ["question_paper_id", 1], ["created_at", "2018-03-12 01:42:30.578211"], ["updated_at", "2018-03-12 01:42:30.578211"]]
 (142.8ms)  commit transaction
Completed 406 Not Acceptable in 268ms (ActiveRecord: 147.8ms)

ActionController::UnknownFormat (ActionController::UnknownFormat):

app/controllers/question_paper_generations_controller.rb:64:in 'composition_create'

После раундов отладки я узнал, что он ответил в HTML, а не на JS, которого я не хочу. Затем я обнаружил gem - remotipart, который мне не нужно добавлять hidden_tag, и форма может быть отправлена через Ajax, но это не работает для Rails 5.1. Итак, любая идея о том, как я могу это сделать?