TrueClass的未定义方法`model_name’：DeviseConfirmations的类（Rails 4，设计）
在我的Rails应用程序中，为了在用户注册时将用户国家（使用Geocoder gem）保存到User表中，并使用另一个SO问题 ，我在控制器/ confirmations_controller.rb中更改了一些内容但是我遇到了严重的错误我不明白也不设法解决：
def after_sign_up_path_for(resource) if Devise.allow_insecure_sign_in_after_confirmation resource.update(user_country: request.location.country) after_sign_in_path_for(resource) else resource.update(user_country: request.location.country) root_path end end 奇怪的是，用户在我的本地数据库中保存了一切正常（包括我想要的用户国家）。 但是当我得到一个包含以下错误消息的错误页面时，必须发生一些事情：
undefined method `model_name' for TrueClass:Class
整个错误日志：
(0.8ms) COMMIT (0.5ms) BEGIN SQL (1.3ms) UPDATE "users" SET "remember_created_at" = $1, "updated_at" = $2 WHERE "users"."id" = 427 [["remember_created_at", 2014-06-24 10:52:32 UTC], ["updated_at", 2014-06-24 12:52:32 +0200]] (0.7ms) COMMIT (0.4ms) BEGIN SQL (0.9ms) UPDATE "users" SET "last_sign_in_at" = $1, "current_sign_in_at" = $2, "last_sign_in_ip" = $3, "current_sign_in_ip" = $4, "sign_in_count" = $5, "updated_at" = $6 WHERE "users"."id" = 427 [["last_sign_in_at", 2014-06-24 10:52:32 UTC], ["current_sign_in_at", 2014-06-24 10:52:32 UTC], ["last_sign_in_ip", "24.193.83.1"], ["current_sign_in_ip", "24.193.83.1"], ["sign_in_count", 1], ["updated_at", 2014-06-24 12:52:32 +0200]] (0.7ms) COMMIT (0.4ms) BEGIN User Exists (1.0ms) SELECT 1 AS one FROM "users" WHERE (LOWER("users"."email") = LOWER('mathieu.proffit75++edaaaaaa+++@gmail.com') AND "users"."id" != 427) LIMIT 1 SQL (1.3ms) UPDATE "users" SET "user_country" = $1, "updated_at" = $2 WHERE "users"."id" = 427 [["user_country", "United States"], ["updated_at", 2014-06-24 12:52:32 +0200]] (0.7ms) COMMIT Completed 500 Internal Server Error in 4984ms NoMethodError - undefined method `model_name' for TrueClass:Class: actionpack (4.0.5) lib/action_controller/model_naming.rb:9:in `model_name_from_record_or_class' actionpack (4.0.5) lib/action_dispatch/routing/polymorphic_routes.rb:182:in `build_named_route_call' actionpack (4.0.5) lib/action_dispatch/routing/polymorphic_routes.rb:120:in `polymorphic_url' actionpack (4.0.5) lib/action_dispatch/routing/url_for.rb:159:in `url_for' actionpack (4.0.5) lib/action_controller/metal/rendering.rb:68:in `_process_options' actionpack (4.0.5) lib/action_controller/metal/streaming.rb:202:in `_process_options' actionpack (4.0.5) lib/abstract_controller/rendering.rb:119:in `render_to_body' actionpack (4.0.5) lib/action_controller/metal/rendering.rb:33:in `render_to_body' actionpack (4.0.5) lib/action_controller/metal/renderers.rb:26:in `render_to_body' actionpack (4.0.5) lib/abstract_controller/rendering.rb:97:in `render' actionpack (4.0.5) lib/action_controller/metal/rendering.rb:16:in `render' actionpack (4.0.5) lib/action_controller/metal/instrumentation.rb:41:in `block (2 levels) in render' activesupport (4.0.5) lib/active_support/core_ext/benchmark.rb:12:in `block in ms' /home/mreisner/.rvm/rubies/ruby-2.0.0-p451/lib/ruby/2.0.0/benchmark.rb:296:in `realtime' activesupport (4.0.5) lib/active_support/core_ext/benchmark.rb:12:in `ms' actionpack (4.0.5) lib/action_controller/metal/instrumentation.rb:41:in `block in render' actionpack (4.0.5) lib/action_controller/metal/instrumentation.rb:84:in `cleanup_view_runtime' activerecord (4.0.5) lib/active_record/railties/controller_runtime.rb:25:in `cleanup_view_runtime' actionpack (4.0.5) lib/action_controller/metal/instrumentation.rb:40:in `render' actionpack (4.0.5) lib/action_controller/metal/implicit_render.rb:10:in `default_render' actionpack (4.0.5) lib/action_controller/metal/responder.rb:233:in `default_render' actionpack (4.0.5) lib/action_controller/metal/responder.rb:161:in `to_html' actionpack (4.0.5) lib/action_controller/metal/responder.rb:154:in `respond' actionpack (4.0.5) lib/action_controller/metal/responder.rb:147:in `call' actionpack (4.0.5) lib/action_controller/metal/mime_responds.rb:330:in `respond_with' devise (3.2.4) app/controllers/devise/registrations_controller.rb:20:in `create' actionpack (4.0.5) lib/action_controller/metal/implicit_render.rb:4:in `send_action' actionpack (4.0.5) lib/abstract_controller/base.rb:189:in `process_action' actionpack (4.0.5) lib/action_controller/metal/rendering.rb:10:in `process_action' actionpack (4.0.5) lib/abstract_controller/callbacks.rb:18:in `block in process_action' activesupport (4.0.5) lib/active_support/callbacks.rb:483:in `_run__1192109421260337467__process_action__callbacks' activesupport (4.0.5) lib/active_support/callbacks.rb:80:in `run_callbacks' actionpack (4.0.5) lib/abstract_controller/callbacks.rb:17:in `process_action' actionpack (4.0.5) lib/action_controller/metal/rescue.rb:29:in `process_action' actionpack (4.0.5) lib/action_controller/metal/instrumentation.rb:31:in `block in process_action' activesupport (4.0.5) lib/active_support/notifications.rb:159:in `block in instrument' activesupport (4.0.5) lib/active_support/notifications/instrumenter.rb:20:in `instrument' activesupport (4.0.5) lib/active_support/notifications.rb:159:in `instrument' actionpack (4.0.5) lib/action_controller/metal/instrumentation.rb:30:in `process_action' actionpack (4.0.5) lib/action_controller/metal/params_wrapper.rb:250:in `process_action' activerecord (4.0.5) lib/active_record/railties/controller_runtime.rb:18:in `process_action' actionpack (4.0.5) lib/abstract_controller/base.rb:136:in `process' actionpack (4.0.5) lib/abstract_controller/rendering.rb:44:in `process' actionpack (4.0.5) lib/action_controller/metal.rb:195:in `dispatch' actionpack (4.0.5) lib/action_controller/metal/rack_delegation.rb:13:in `dispatch' actionpack (4.0.5) lib/action_controller/metal.rb:231:in `block in action' actionpack (4.0.5) lib/action_dispatch/routing/route_set.rb:80:in `call' actionpack (4.0.5) lib/action_dispatch/routing/route_set.rb:80:in `dispatch' actionpack (4.0.5) lib/action_dispatch/routing/route_set.rb:48:in `call' actionpack (4.0.5) lib/action_dispatch/routing/mapper.rb:44:in `call' actionpack (4.0.5) lib/action_dispatch/journey/router.rb:71:in `block in call' actionpack (4.0.5) lib/action_dispatch/journey/router.rb:59:in `each' actionpack (4.0.5) lib/action_dispatch/journey/router.rb:59:in `call' actionpack (4.0.5) lib/action_dispatch/routing/route_set.rb:674: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 (1.5.2) lib/rack/etag.rb:23:in `call' rack (1.5.2) lib/rack/conditionalget.rb:35:in `call' rack (1.5.2) lib/rack/head.rb:11:in `call' actionpack (4.0.5) lib/action_dispatch/middleware/params_parser.rb:27:in `call' actionpack (4.0.5) lib/action_dispatch/middleware/flash.rb:241:in `call' rack (1.5.2) lib/rack/session/abstract/id.rb:225:in `context' rack (1.5.2) lib/rack/session/abstract/id.rb:220:in `call' actionpack (4.0.5) lib/action_dispatch/middleware/cookies.rb:486:in `call' activerecord (4.0.5) lib/active_record/query_cache.rb:36:in `call' activerecord (4.0.5) lib/active_record/connection_adapters/abstract/connection_pool.rb:626:in `call' activerecord (4.0.5) lib/active_record/migration.rb:373:in `call' actionpack (4.0.5) lib/action_dispatch/middleware/callbacks.rb:29:in `block in call' activesupport (4.0.5) lib/active_support/callbacks.rb:373:in `_run__3240580690818246217__call__callbacks' activesupport (4.0.5) lib/active_support/callbacks.rb:80:in `run_callbacks' actionpack (4.0.5) lib/action_dispatch/middleware/callbacks.rb:27:in `call' actionpack (4.0.5) lib/action_dispatch/middleware/reloader.rb:64:in `call' actionpack (4.0.5) lib/action_dispatch/middleware/remote_ip.rb:76:in `call' better_errors (1.1.0) lib/better_errors/middleware.rb:84:in `protected_app_call' better_errors (1.1.0) lib/better_errors/middleware.rb:79:in `better_errors_call' better_errors (1.1.0) lib/better_errors/middleware.rb:56:in `call' actionpack (4.0.5) lib/action_dispatch/middleware/debug_exceptions.rb:17:in `call' actionpack (4.0.5) lib/action_dispatch/middleware/show_exceptions.rb:30:in `call' railties (4.0.5) lib/rails/rack/logger.rb:38:in `call_app' railties (4.0.5) lib/rails/rack/logger.rb:20:in `block in call' activesupport (4.0.5) lib/active_support/tagged_logging.rb:68:in `block in tagged' activesupport (4.0.5) lib/active_support/tagged_logging.rb:26:in `tagged' activesupport (4.0.5) lib/active_support/tagged_logging.rb:68:in `tagged' railties (4.0.5) lib/rails/rack/logger.rb:20:in `call' quiet_assets (1.0.2) lib/quiet_assets.rb:18:in `call_with_quiet_assets' actionpack (4.0.5) lib/action_dispatch/middleware/request_id.rb:21:in `call' rack (1.5.2) lib/rack/methodoverride.rb:21:in `call' rack (1.5.2) lib/rack/runtime.rb:17:in `call' activesupport (4.0.5) lib/active_support/cache/strategy/local_cache.rb:83:in `call' rack (1.5.2) lib/rack/lock.rb:17:in `call' rack (1.5.2) lib/rack/sendfile.rb:112:in `call' railties (4.0.5) lib/rails/engine.rb:511:in `call' railties (4.0.5) lib/rails/application.rb:97:in `call' rack (1.5.2) lib/rack/lock.rb:17:in `call' rack (1.5.2) lib/rack/content_length.rb:14:in `call' rack (1.5.2) lib/rack/handler/webrick.rb:60:in `service' /home/mreisner/.rvm/rubies/ruby-2.0.0-p451/lib/ruby/2.0.0/webrick/httpserver.rb:138:in `service' /home/mreisner/.rvm/rubies/ruby-2.0.0-p451/lib/ruby/2.0.0/webrick/httpserver.rb:94:in `run' /home/mreisner/.rvm/rubies/ruby-2.0.0-p451/lib/ruby/2.0.0/webrick/server.rb:295:in `block in start_thread'
试着这样做
def after_sign_up_path_for(resource) if Devise.allow_insecure_sign_in_after_confirmation resource.update(user_country: request.location.country) super(resource) else resource.update(user_country: request.location.country) root_path end end