在Rails 4中創建API - 未初始化的常量Api :: V1 :: UsersController

Question

對於個人項目，我想在Rails 4中創建Restful Web服務。

所以，我使用rails-api創建了我的第一個項目，並添加了以下代碼：

在MyProject> config目錄中的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>應用>控制器> API> V1>用戶目錄

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

當我使用命令行rails s啟動rails服務器並轉到此URL時： http://localhost:3000/api/v1/users/show我遇到此錯誤：

未初始化的常量Api :: V1 :: UsersController

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

應用程序跟蹤| 框架跟蹤| 完全跟蹤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在constantize const_get' activesupport (4.0.4) lib/active_support/inflector/methods.rb:228:in塊'activesupport（4.0。 4）lib / active_support / inflector / methods.rb：224：在each' activesupport (4.0.4) lib/active_support/inflector/methods.rb:224:in inject'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:in controller_reference'actionpack（4.0.4）lib / action_dispatch / routing / route_set.rb:66:in controller' actionpack (4.0.4) lib/action_dispatch/routing/route_set.rb:44:in調用'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每個'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電話'機架（1.5.2）lib / rack / etag.rb:23：在call' rack (1.5.2) lib/rack/conditionalget.rb:25:in call' rack (1.5.2) lib/rack/conditionalget.rb:25:in調用'rack（1.5.2）lib / rack / head.rb：11：在call' actionpack (4.0.4) lib/action_dispatch/middleware/params_parser.rb:27:in調用'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調用'activerecord（4.0.4） ）lib / active_record / migration.rb：373：在call' actionpack (4.0.4) lib/action_dispatch/middleware/callbacks.rb:29:in塊中調用'activesupport（4.0.4）lib / active_support / callbacks.rb ：373：in _run__4323212420903942114__call__callbacks' activesupport (4.0.4) lib/active_support/callbacks.rb:80:in run_callbacks'actionpack（4.0.4）lib / action_dispatch / middleware / callbacks.rb:27:in call' actionpack (4.0.4) lib/action_dispatch/middleware/reloader.rb:64:in調用'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調用'actionpack（4.0.4）lib / action_dispatch / mi中 ddleware / show_exceptions.rb:30：在call' railties (4.0.4) lib/rails/rack/logger.rb:38:in call_app'railties（4.0.4）lib / rails / rack / logger.rb：20： in block in call' activesupport (4.0.4) lib/active_support/tagged_logging.rb:68:in block in tagged'activesupport（4.0.4）lib / active_support / tagged_logging.rb:26:in tagged' activesupport (4.0.4) lib/active_support/tagged_logging.rb:68:in標記為'railties（4.0.4）lib / rails / rack / logger.rb：20：在call' actionpack (4.0.4) lib/action_dispatch/middleware/request_id.rb:21:in呼叫'機架（1.5.2）lib / rack / runtime.rb：17：在call' activesupport (4.0.4) lib/active_support/cache/strategy/local_cache.rb:83:in呼叫'機架（ 1.5.2）lib / rack / lock.rb:17：在call' actionpack (4.0.4) lib/action_dispatch/middleware/static.rb:64:in調用'railties（4.0.4）lib / rails / engine中。 rb：511：在call' railties (4.0.4) lib/rails/application.rb:97:in呼叫'機架（1.5.2）lib / rack / lock.rb：17：在call' rack (1.5.2) lib/rack/content_length.rb:14:in調用'rack（1.5.2）lib / rack / handler / webrick.rb中： 60： 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 /Jean/ run' /Users/Jean/.rvm/rubies/ruby-2.1.2/lib/ruby/2.1.0/webrick/server.rb:295:in /rubies/ruby-2.1.2/lib/ruby/2.1.0/webrick run' /Users/Jean/.rvm/rubies/ruby-2.1.2/lib/ruby/2.1.0/webrick/server.rb:295:in塊'

我發現Stackoverflow上有很多帖子有相同的錯誤，但答案並沒有幫助我解決我的問題。

謝謝 ！

Answer 1

如果你有這條路：

MyProject> app> controllers> api> v1> users

控制器應該是class Api::V1::Users::UsersController如果這樣：

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

然后是class Api::V1::UsersController

對於首字母縮寫名稱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