在Rails 4中创建API - 未初始化的常量Api :: V1 :: UsersController

Question

对于个人项目,我想在Rails 4中创建Restful Web服务.

所以,我创建了我的第一个项目,rails-api并添加了以下代码:

在MyProject> config目录中的routes.rb

MyProject::Application.routes.draw do
    namespace :api, defaults: {format: 'json'} do
        namespace :v1 do
            resources :users
        end
    end
end

users_controller.rb在MyProject的>应用>控制器> API> V1>用户目录

module Api
    module V1
        class UsersController < ApplicationController
            def index
            end

            def create
            end

            def show
            end

            def update
            end

            def delete
            end
        end 
    end
end

当我使用命令行启动rails服务器rails s并转到此URL时:http://localhost:3000/api/v1/users/show我遇到此错误:

未初始化的常量Api :: V1 :: UsersController

Rails.root:/ Users/Jean/Development/MyProject

应用程序跟踪| 框架跟踪| 完全跟踪activesupport(4.0.4)lib/active_support/inflector/methods.rb:228:在const_get' activesupport (4.0.4) lib/active_support/inflector/methods.rb:228:in constantize 中的块'activesupport(4.0.4)lib/active_support/inflector/methods.rb:224:in each' activesupport (4.0.4) lib/active_support/inflector/methods.rb:224:ininject'activesupport(4.0. 4)lib/active_support/inflector/methods.rb:224:在 constantize' actionpack (4.0.4) lib/action_dispatch/routing/route_set.rb:76:incontroller_reference'actionpack(4.0.4)中lib/action_dispatch/routing/route_set.rb:66:在 controller' actionpack (4.0.4) lib/action_dispatch/routing/route_set.rb:44:in调用'actionpack(4.0.4)lib/action_dispatch/journey/router.rb:71:在block in call' actionpack (4.0.4) lib/action_dispatch/journey/router.rb:59:in每个'actionpack(4.0.4)lib/action_dispatch/journey/router.rb:59:在call' actionpack (4.0.4) lib/action_dispatch/routing/route_set.rb:674:in 呼叫'机架(1.5.2)lib/rack/etag.rb:23:在call' rack (1.5.2) lib/rack/conditionalget.rb:25:in呼叫'机架(1.5.2)lib/rack/head.rb:11:在call' actionpack (4.0.4) lib/action_dispatch/middleware/params_parser.rb:27:in调用'activerecord(4.0.4)lib/active_record/query_cache.rb:36:在call' activerecord (4.0.4) lib/active_record/connection_adapters/abstract/connection_pool.rb:626:in 调用'activerecord(4.0.4)lib/active_record/migration.rb :373:在 call' actionpack (4.0.4) lib/action_dispatch/middleware/callbacks.rb:29:in调用块中'activesupport(4.0.4)lib/active_support/callbacks.rb:373:在 _run__4323212420903942114__call__callbacks' activesupport (4.0.4) lib/active_support/callbacks.rb:80:inrun_callbacks'actionpack(4.0.4)中lib/action_dispatch/middleware/callbacks.rb:27:在call' actionpack (4.0.4) lib/action_dispatch/middleware/reloader.rb:64:in 调用'actionpack( 4.0.4)lib/action_dispatch/middleware/remote_ip.rb:76:在call' actionpack (4.0.4) lib/action_dispatch/middleware/debug_exceptions.rb:17:in 调用'actionpack(4.0.4)lib/action_dispatch/middleware/show_exceptions.rb:3 0:在call' railties (4.0.4) lib/rails/rack/logger.rb:38:incall_app'raxties(4.0.4)lib/rails/rack/logger.rb:20:block in call' activesupport (4.0.4) lib/active_support/tagged_logging.rb:68:in在标记为'activesupport(4.0.4)lib/active_support/tagged_logging.rb的块中:26:在 tagged' activesupport (4.0.4) lib/active_support/tagged_logging.rb:68:in标记为'railties(4.0)中.4)lib/rails/rack/logger.rb:20:在call' actionpack (4.0.4) lib/action_dispatch/middleware/request_id.rb:21:in调用'rack(1.5.2)lib/rack/runtime.rb:17:在call' activesupport (4.0.4) lib/active_support/cache/strategy/local_cache.rb:83:in调用'rack(1.5.2)lib/rack/lock.rb :17:在call' actionpack (4.0.4) lib/action_dispatch/middleware/static.rb:64:in呼叫'railties(4.0.4)lib/rails/engine.rb:511:在call' railties (4.0.4) lib/rails/application.rb:97:in呼叫'机架(1.5.2)lib/rack/lock.rb:17:在call' rack (1.5.2) lib/rack/content_length.rb:14:in呼叫'机架(1.5.2) lib/rack/handler/webrick.rb:60:in service' /Users/Jean/.rvm/rubies/ruby-2.1.2/lib/ruby/2.1.0/webrick/httpserver.rb:138:in service' /Users/Jean/.rvm/rubies/ruby-2.1.2/lib/ruby/2.1.0/webrick/httpserver.rb:94:in run' /Users/Jean/.rvm/rubies/ruby-2.1.2/lib/ruby/2.1.0/webrick/server.rb:295:in block in start_thread"

我发现Stackoverflow上有很多帖子有相同的错误,但答案并没有帮助我解决我的问题.

谢谢 !

Answer 1

如果你有这条路:

MyProject> app> controllers> api> v1> users

控制器应该是class Api::V1::Users::UsersController 这样的:

MyProject> app> controllers> api> v1> users_controller.rb

然后 class Api::V1::UsersController

对于首字母缩略词名称API::V1::UsersController而不是Api::V1::Users::UsersController使用inflectors:

在 config/initializers/inflections.rb

 ActiveSupport::Inflector.inflections(:en) do |inflect|
   inflect.acronym 'API'
 end