Ruby on Rails：文章中的NoMethodError＃Show

Question

我在做http://guides.rubyonrails.org/getting_started.html教程，使用Rails 5和Ruby 2.4创建博客。 在复制并粘贴到Unit-6：添加注释模型的末尾之后，Rails抛出了这个错误：

“文章中的NoMethodError＃Show”：##未定义的方法`article_comments_path'

<h2>Add a comment:</h2>
<%= form_for([@article, @article.comments.build]) do |f| %><!--****Error?****-->

2014年10月26日的Stackoverflow回答说要将routes_comments_path帮助方法添加到routes.rb，如下所示：

resources :articles do
  resources :comments
end

但是语法似乎有所改变。

我的routes.rb看起来像这样：

Rails.application.routes.draw do
    resources :articles
    resources :comments#This creates comments as a nested resource within articles.
    root 'welcome#index'
    # For details on the DSL available within this file, see http://guides.rubyonrails.org/routing.html
end

我没有在终端中输入任何拼写错误，所以我不确定如何继续。 非常感谢任何指导。

我的'耙路线| grep comments的输出是：

comments GET    /comments(.:format)          comments#index
         POST   /comments(.:format)          comments#create

new_comment GET /comments/new(.:format）评论#new edit_comment GET /comments/:id/edit(.:format）评论#edit comment GET /comments/:id(.:format）评论#show PATCH / comments / ：id（。：format）comments＃update PUT /comments/:id(.:format）comments＃update DELETE /comments/:id(.:format）comments＃destroy

我的rake routes输出是：

     Prefix Verb   URI Pattern                  Controller#Action
    articles GET    /articles(.:format)          articles#index
             POST   /articles(.:format)          articles#create
 new_article GET    /articles/new(.:format)      articles#new
edit_article GET    /articles/:id/edit(.:format) articles#edit
     article GET    /articles/:id(.:format)      articles#show
             PATCH  /articles/:id(.:format)      articles#update
             PUT    /articles/:id(.:format)      articles#update
             DELETE /articles/:id(.:format)      articles#destroy
    comments GET    /comments(.:format)          comments#index
             POST   /comments(.:format)          comments#create
 new_comment GET    /comments/new(.:format)      comments#new
edit_comment GET    /comments/:id/edit(.:format) comments#edit
     comment GET    /comments/:id(.:format)      comments#show
             PATCH  /comments/:id(.:format)      comments#update
             PUT    /comments/:id(.:format)      comments#update
             DELETE /comments/:id(.:format)      comments#destroy
        root GET    /                            welcome#index

任何问题？

Answer 1

根据您提供的文档，您应该使用块来嵌套路由：

Rails.application.routes.draw do
resources :articles do
  resources :comments
end
root 'welcome#index'

Ruby不知道这个缩进，所以您的代码格式良好如下所示：

Rails.application.routes.draw do
  resources :articles
  resources :comments#This creates comments as a nested resource within articles.
  root 'welcome#index
end

编辑：您始终可以使用rake routes检查cli中的rake routes

Answer 2

至少根据http://guides.rubyonrails.org/routing.html#nested-resources

你还需要做

resources :articles do
  resources :comments
end

设置此项时会出现哪个错误？ 还尝试重新启动服务器。