未初始化的常数UsersController :: PostComment在rails 3中的应用程序

Question

我刚刚尝试重命名我的控制器以及与其相关的所有文件。

不过，我得到这个错误：

NameError in UsersController#show 

uninitialized constant UsersController::PostComment 

这里的用户控制器

def show 
@user = User.find(params[:id]) 
@microposts = @user.microposts.without_review.paginate page: params[:page], :per_page => 15 
@comment = PostComment.new 
impressionist(@user) 
end 

这里是我的postcomment.rb

class PostComment < ActiveRecord::Base 
    attr_accessible :comment_content 

    belongs_to :user 
    belongs_to :micropost 

    validates :comment_content, presence: true 
    validates :user_id, presence: true 
    validates :micropost_id, presence: true 

    default_scope order: 'postcomments.created_at ASC' 
end 

的routes.rb有

resources :microposts do 
    resources :postcomments 

终于全部跟踪

app/controllers/users_controller.rb:17:in `show' 
actionpack (3.2.3) lib/action_controller/metal/implicit_render.rb:4:in `send_action' 
actionpack (3.2.3) lib/abstract_controller/base.rb:167:in `process_action' 
actionpack (3.2.3) lib/action_controller/metal/rendering.rb:10:in `process_action' 
actionpack (3.2.3) lib/abstract_controller/callbacks.rb:18:in `block in process_action' 
activesupport (3.2.3) lib/active_support/callbacks.rb:436:in `_run__602137435__process_action__956769240__callbacks' 
activesupport (3.2.3) lib/active_support/callbacks.rb:405:in `__run_callback' 
activesupport (3.2.3) lib/active_support/callbacks.rb:385:in `_run_process_action_callbacks' 
activesupport (3.2.3) lib/active_support/callbacks.rb:81:in `run_callbacks' 
actionpack (3.2.3) lib/abstract_controller/callbacks.rb:17:in `process_action' 
actionpack (3.2.3) lib/action_controller/metal/rescue.rb:29:in `process_action' 
actionpack (3.2.3) lib/action_controller/metal/instrumentation.rb:30:in `block in process_action' 
activesupport (3.2.3) lib/active_support/notifications.rb:123:in `block in instrument' 
activesupport (3.2.3) lib/active_support/notifications/instrumenter.rb:20:in `instrument' 
activesupport (3.2.3) lib/active_support/notifications.rb:123:in `instrument' 
actionpack (3.2.3) lib/action_controller/metal/instrumentation.rb:29:in `process_action' 
actionpack (3.2.3) lib/action_controller/metal/params_wrapper.rb:205:in `process_action' 
activerecord (3.2.3) lib/active_record/railties/controller_runtime.rb:18:in `process_action' 
actionpack (3.2.3) lib/abstract_controller/base.rb:121:in `process' 
actionpack (3.2.3) lib/abstract_controller/rendering.rb:45:in `process' 
actionpack (3.2.3) lib/action_controller/metal.rb:203:in `dispatch' 
actionpack (3.2.3) lib/action_controller/metal/rack_delegation.rb:14:in `dispatch' 
actionpack (3.2.3) lib/action_controller/metal.rb:246:in `block in action' 
actionpack (3.2.3) lib/action_dispatch/routing/route_set.rb:73:in `call' 
actionpack (3.2.3) lib/action_dispatch/routing/route_set.rb:73:in `dispatch' 
actionpack (3.2.3) lib/action_dispatch/routing/route_set.rb:36:in `call' 
journey (1.0.4) lib/journey/router.rb:68:in `block in call' 
journey (1.0.4) lib/journey/router.rb:56:in `each' 
journey (1.0.4) lib/journey/router.rb:56:in `call' 
actionpack (3.2.3) lib/action_dispatch/routing/route_set.rb:600:in `call' 
warden (1.2.1) lib/warden/manager.rb:35:in `block in call' 
warden (1.2.1) lib/warden/manager.rb:34:in `catch' 
warden (1.2.1) lib/warden/manager.rb:34:in `call' 
actionpack (3.2.3) lib/action_dispatch/middleware/best_standards_support.rb:17:in `call' 
rack (1.4.5) lib/rack/etag.rb:23:in `call' 
rack (1.4.5) lib/rack/conditionalget.rb:25:in `call' 
actionpack (3.2.3) lib/action_dispatch/middleware/head.rb:14:in `call' 
actionpack (3.2.3) lib/action_dispatch/middleware/params_parser.rb:21:in `call' 
actionpack (3.2.3) lib/action_dispatch/middleware/flash.rb:242:in `call' 
rack (1.4.5) lib/rack/session/abstract/id.rb:210:in `context' 
rack (1.4.5) lib/rack/session/abstract/id.rb:205:in `call' 
actionpack (3.2.3) lib/action_dispatch/middleware/cookies.rb:338:in `call' 
activerecord (3.2.3) lib/active_record/query_cache.rb:64:in `call' 
activerecord (3.2.3) lib/active_record/connection_adapters/abstract/connection_pool.rb:467:in `call' 
actionpack (3.2.3) lib/action_dispatch/middleware/callbacks.rb:28:in `block in call' 
activesupport (3.2.3) lib/active_support/callbacks.rb:405:in `_run__788066434__call__637757501__callbacks' 
activesupport (3.2.3) lib/active_support/callbacks.rb:405:in `__run_callback' 
activesupport (3.2.3) lib/active_support/callbacks.rb:385:in `_run_call_callbacks' 
activesupport (3.2.3) lib/active_support/callbacks.rb:81:in `run_callbacks' 
actionpack (3.2.3) lib/action_dispatch/middleware/callbacks.rb:27:in `call' 
actionpack (3.2.3) lib/action_dispatch/middleware/reloader.rb:65:in `call' 
actionpack (3.2.3) lib/action_dispatch/middleware/remote_ip.rb:31:in `call' 
actionpack (3.2.3) lib/action_dispatch/middleware/debug_exceptions.rb:16:in `call' 
actionpack (3.2.3) lib/action_dispatch/middleware/show_exceptions.rb:56:in `call' 
railties (3.2.3) lib/rails/rack/logger.rb:26:in `call_app' 
railties (3.2.3) lib/rails/rack/logger.rb:16:in `call' 
actionpack (3.2.3) lib/action_dispatch/middleware/request_id.rb:22:in `call' 
rack (1.4.5) lib/rack/methodoverride.rb:21:in `call' 
rack (1.4.5) lib/rack/runtime.rb:17:in `call' 
activesupport (3.2.3) lib/active_support/cache/strategy/local_cache.rb:72:in `call' 
rack (1.4.5) lib/rack/lock.rb:15:in `call' 
actionpack (3.2.3) lib/action_dispatch/middleware/static.rb:62:in `call' 
railties (3.2.3) lib/rails/engine.rb:479:in `call' 
railties (3.2.3) lib/rails/application.rb:220:in `call' 
rack (1.4.5) lib/rack/content_length.rb:14:in `call' 
railties (3.2.3) lib/rails/rack/log_tailer.rb:14:in `call' 
rack (1.4.5) lib/rack/handler/webrick.rb:59:in `service' 
C:/RailsInstaller/Ruby1.9.3/lib/ruby/1.9.1/webrick/httpserver.rb:138:in `service' 
C:/RailsInstaller/Ruby1.9.3/lib/ruby/1.9.1/webrick/httpserver.rb:94:in `run' 
C:/RailsInstaller/Ruby1.9.3/lib/ruby/1.9.1/webrick/server.rb:191:in `block in start_thread' 

Answer 1

如果你有一个名为postcomment.rb那么它将映射到类Postcomment。如果你想要它叫PostComment你需要命名它post_comment.rb。

这是因为自动装载机的工作原理。它有你需要遵循的约定，否则将无法找到你的模型。

在Ruby中记住一切都区分大小写。