Ruby on Rails: NoMethodError in Articles#Show

Question

I'm doing the http://guides.rubyonrails.org/getting_started.html tutorial, creating a blog using Rails 5 & Ruby 2.4. After copying and pasting my way through to the end of Unit-6: Adding a Comments model, Rails threw this error:

"NoMethodError in Articles#Show":undefined method `article_comments_path' for #<#

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

A Stackoverflow answer from Oct. 26, 2014 says to add an article_comments_path helper method to routes.rb like this:

resources :articles do
  resources :comments
end

But the syntax seems to have changed a bit since.

My routes.rb looks like this:

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

I haven't found any spelling errors entered in the terminal, so I'm not really sure on how to proceed. Any guidance is greatly appreciated.

My 'rake routes | grep comments' output is:

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

and my rake routes output is:

     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

Any problems?

Answer 1

According to the docs you provided you should use a block for nested routes:

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

Ruby is not aware of this indentation so your code well formatted looks like this:

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

Edit: You can always check your routs within the cli with rake routes

Answer 2

Atleast according to http://guides.rubyonrails.org/routing.html#nested-resources

You still need to do

resources :articles do
  resources :comments
end

Which error do you get when you set this? Also try restarting your server.