“respond_to do | format |”抛出UnknownFormat错误

我正在尝试使用ajax从控制器渲染一个js文件。 这个确切的代码以前总是工作，它甚至可以在其他方法中工作，但我突然开始收到此错误：

ActionController::UnknownFormat in MoviesController#vote ActionController::UnknownFormat 

电影控制器：

 def vote ... respond_to do |format| #The error points to this line. format.js end end 

vote.js.erb：

 $('#votes').html(""); 

链接：

movies.html.erb：

_votes.html.erb

routes.rb中：

 post 'movies/vote' => 'movies#vote', as: 'vote' 

为什么我突然收到此错误？ 为什么它在不同的环境中工作而在这个环境中不工作？

使用Rails 4.0.10

更新：堆栈跟踪

应用跟踪：

 app/controllers/movies_controller.rb:394:in `vote' 

全部追踪：

 actionpack (4.0.10) lib/action_controller/metal/mime_responds.rb:372:in `retrieve_collector_from_mimes' actionpack (4.0.10) lib/action_controller/metal/mime_responds.rb:189:in `respond_to' app/controllers/movies_controller.rb:394:in `vote' actionpack (4.0.10) lib/action_controller/metal/implicit_render.rb:4:in `send_action' actionpack (4.0.10) lib/abstract_controller/base.rb:189:in `process_action' actionpack (4.0.10) lib/action_controller/metal/rendering.rb:10:in `process_action' actionpack (4.0.10) lib/abstract_controller/callbacks.rb:18:in `block in process_action' activesupport (4.0.10) lib/active_support/callbacks.rb:413:in `_run__1492335060096380544__process_action__callbacks' activesupport (4.0.10) lib/active_support/callbacks.rb:80:in `run_callbacks' actionpack (4.0.10) lib/abstract_controller/callbacks.rb:17:in `process_action' actionpack (4.0.10) lib/action_controller/metal/rescue.rb:29:in `process_action' actionpack (4.0.10) lib/action_controller/metal/instrumentation.rb:31:in `block in process_action' activesupport (4.0.10) lib/active_support/notifications.rb:159:in `block in instrument' activesupport (4.0.10) lib/active_support/notifications/instrumenter.rb:20:in `instrument' activesupport (4.0.10) lib/active_support/notifications.rb:159:in `instrument' actionpack (4.0.10) lib/action_controller/metal/instrumentation.rb:30:in `process_action' actionpack (4.0.10) lib/action_controller/metal/params_wrapper.rb:250:in `process_action' activerecord (4.0.10) lib/active_record/railties/controller_runtime.rb:18:in `process_action' actionpack (4.0.10) lib/abstract_controller/base.rb:136:in `process' actionpack (4.0.10) lib/abstract_controller/rendering.rb:44:in `process' actionpack (4.0.10) lib/action_controller/metal.rb:195:in `dispatch' actionpack (4.0.10) lib/action_controller/metal/rack_delegation.rb:13:in `dispatch' actionpack (4.0.10) lib/action_controller/metal.rb:231:in `block in action' actionpack (4.0.10) lib/action_dispatch/routing/route_set.rb:82:in `call' actionpack (4.0.10) lib/action_dispatch/routing/route_set.rb:82:in `dispatch' actionpack (4.0.10) lib/action_dispatch/routing/route_set.rb:50:in `call' actionpack (4.0.10) lib/action_dispatch/journey/router.rb:71:in `block in call' actionpack (4.0.10) lib/action_dispatch/journey/router.rb:59:in `each' actionpack (4.0.10) lib/action_dispatch/journey/router.rb:59:in `call' actionpack (4.0.10) lib/action_dispatch/routing/route_set.rb:676:in `call' warden (1.2.3) lib/warden/manager.rb:35:in `block in call' warden (1.2.3) lib/warden/manager.rb:34:in `catch' warden (1.2.3) lib/warden/manager.rb:34:in `call' rack (1.5.5) lib/rack/etag.rb:23:in `call' rack (1.5.5) lib/rack/conditionalget.rb:25:in `call' rack (1.5.5) lib/rack/head.rb:11:in `call' actionpack (4.0.10) lib/action_dispatch/middleware/params_parser.rb:27:in `call' actionpack (4.0.10) lib/action_dispatch/middleware/flash.rb:241:in `call' rack (1.5.5) lib/rack/session/abstract/id.rb:225:in `context' rack (1.5.5) lib/rack/session/abstract/id.rb:220:in `call' actionpack (4.0.10) lib/action_dispatch/middleware/cookies.rb:486:in `call' activerecord (4.0.10) lib/active_record/query_cache.rb:36:in `call' activerecord (4.0.10) lib/active_record/connection_adapters/abstract/connection_pool.rb:626:in `call' activerecord (4.0.10) lib/active_record/migration.rb:373:in `call' actionpack (4.0.10) lib/action_dispatch/middleware/callbacks.rb:29:in `block in call' activesupport (4.0.10) lib/active_support/callbacks.rb:373:in `_run__2656547782179467807__call__callbacks' activesupport (4.0.10) lib/active_support/callbacks.rb:80:in `run_callbacks' actionpack (4.0.10) lib/action_dispatch/middleware/callbacks.rb:27:in `call' actionpack (4.0.10) lib/action_dispatch/middleware/reloader.rb:64:in `call' actionpack (4.0.10) lib/action_dispatch/middleware/remote_ip.rb:76:in `call' actionpack (4.0.10) lib/action_dispatch/middleware/debug_exceptions.rb:17:in `call' web-console (2.2.1) lib/web_console/middleware.rb:39:in `call' actionpack (4.0.10) lib/action_dispatch/middleware/show_exceptions.rb:30:in `call' railties (4.0.10) lib/rails/rack/logger.rb:38:in `call_app' railties (4.0.10) lib/rails/rack/logger.rb:20:in `block in call' activesupport (4.0.10) lib/active_support/tagged_logging.rb:68:in `block in tagged' activesupport (4.0.10) lib/active_support/tagged_logging.rb:26:in `tagged' activesupport (4.0.10) lib/active_support/tagged_logging.rb:68:in `tagged' railties (4.0.10) lib/rails/rack/logger.rb:20:in `call' actionpack (4.0.10) lib/action_dispatch/middleware/request_id.rb:21:in `call' rack (1.5.5) lib/rack/methodoverride.rb:21:in `call' rack (1.5.5) lib/rack/runtime.rb:17:in `call' activesupport (4.0.10) lib/active_support/cache/strategy/local_cache.rb:83:in `call' rack (1.5.5) lib/rack/lock.rb:17:in `call' actionpack (4.0.10) lib/action_dispatch/middleware/static.rb:64:in `call' rack (1.5.5) lib/rack/sendfile.rb:112:in `call' railties (4.0.10) lib/rails/engine.rb:511:in `call' railties (4.0.10) lib/rails/application.rb:97:in `call' rack (1.5.5) lib/rack/lock.rb:17:in `call' rack (1.5.5) lib/rack/content_length.rb:14:in `call' rack (1.5.5) lib/rack/handler/webrick.rb:60:in `service' /home/greg/.rvm/rubies/ruby-2.0.0-p648/lib/ruby/2.0.0/webrick/httpserver.rb:138:in `service' /home/greg/.rvm/rubies/ruby-2.0.0-p648/lib/ruby/2.0.0/webrick/httpserver.rb:94:in `run' /home/greg/.rvm/rubies/ruby-2.0.0-p648/lib/ruby/2.0.0/webrick/server.rb:295:in `block in start_thread' 

Answer 1

您可以指定路径助手的format选项，以指示链接为js而不是默认的html 。 像这样指定：

 <%= link_to "vote", vote_path(format: :js), method: :post, remote: true %> 

我过去曾经遇到过与某些版本的Rails一起工作的问题，但我只有轶事证据。 我发现在这种情况下工作的是：

 <%= link_to "vote", "#{vote_path}.js", method: :post, remote: true %> 

在第二种情况下，您只需将.js扩展名附加到将触发js格式的url路径。 优雅和蛮力，只有在尝试正确的方式失败后使用，但它确实有效。

Answer 2

尝试：

 def vote respond_to do |format| if @comment.update(comment_params) format.js {render nothing: true} format.json { render :show, status: :ok, location: @comment } else format.html { render :edit } format.json { render json: @comment.errors, status: :unprocessable_entity } end end end 

如果语句成功运行，如@ comment.update（comment_params），则注释成功更新，然后执行formate.js，但如果由于某种原因失败，则会发现其他渲染语句。 如果它不存在，则会出现Unknown formate错误。