The action 'show' could not be found for CommentsController - Ruby Tutorial

Question

I am trying to follow the following guide for starting Ruby on Rails. Everything went well until I try to destroy (delete comments).

I receive the following error: The action 'show' could not be found for CommentsController

I will post my code below.

http://guides.rubyonrails.org/getting_started.html

comments_controller.rb

class CommentsController < ApplicationController

  http_basic_authenticate_with name: "dhh", password: "secret", only: :destroy

    def create
        @article = Article.find(params[:article_id])
        @comment = @article.comments.create(comment_params)
        redirect_to article_path(@article)
    end

    def destroy
        @article = Article.find(params[:article_id])
        @comment = @article.comments.find(params[:id])
        @comment.destroy
        redirect_to article_path(@article)
    end

    private
        def comment_params
          params.require(:comment).permit(:commenter, :body)
        end

end

articles_controller

class ArticlesController < ApplicationController

 http_basic_authenticate_with name: "dhh", password: "secret", except: [:index, :show]

    def index
       @articles = Article.all
    end

    def show
        @article = Article.find(params[:id])
    end

    def new
        @article = Article.new 
    end

    def edit
      @article = Article.find(params[:id])
    end

    def create
      @article = Article.new(article_params)

      if @article.save
        redirect_to @article
      else
        render 'new'
      end
    end

    def update
      @article = Article.find(params[:id])

      if @article.update(article_params)
        redirect_to @article
      else
        render 'edit'
      end
    end

    def destroy
      @article = Article.find(params[:id])
      @article.destroy

      redirect_to articles_path
    end

    private
      def article_params
        params.require(:article).permit(:title, :text)
      end
end

routes.rb

Rails.application.routes.draw do

  resources :articles do
    resources :comments
  end

  root 'welcome#index'
end

article.rb

class Article < ActiveRecord::Base

    has_many :comments, dependent: :destroy

    validates :title, presence: true,
                      length: { minimum: 5}
end

comment.rb

class Comment < ActiveRecord::Base
  belongs_to :article
end

articles/index.html.erb

<h1>Listing Articles</h1>

<%= link_to 'New article', new_article_path %>

<table>
  <tr>
    <th>Title</th>
    <th>Text</th>
    <th colspan="3"></th>
  </tr>

  <% @articles.each do |article| %>
    <tr>
      <td><%= article.title %></td>
      <td><%= article.text %></td>
      <td><%= link_to 'Show', article_path(article) %></td>
      <td><%= link_to 'Edit', edit_article_path(article) %></td>
      <td><%= link_to 'Destroy', article_path(article),
              method: :delete,
              data: { confirm: 'Are you sure?' } %></td>
    </tr>
  <% end %>
</table>

Just not sure what it can be. Please advise. I will supply more code if needed.

Answer 1

I ran into same problem but adding

<%= javascript_pack_tag 'application', 'data-turbolinks-track': 'reload' %>

worked for me rails 6 and webpack you should use this

Answer 2

I have the same problem and I tried to add this to comments_controller.rb and it works

def show
@article = Article.find(params[:article_id])
@comment = @article.comments.find(params[:id])
@comment.destroy
redirect_to article_path(@article)
end

Answer 3

I know this is old, but the tutorial "Getting Started with Rails" is still the top result on Google for those looking to start building web applications using Rails.

I encountered the same issue today and it kind of makes sense. If you want to delete a comment, you can't simply navigate to it with a GET request, you need to use a DELETE method.

I got around this by replacing link_to with button_to hoping that Rails would sort out the "magic" and it did.

Code used:

<%= button_to 'Destroy Comment', [comment.article, comment],
                method: :delete,
                data: { confirm: "Are you sure?" } %>

Instead of

<%= link_to 'Destroy Comment', [comment.article, comment],
                method: :delete,
                data: { confirm: "Are you sure?" } %>

Answer 4

I have had some similar issues, for example:

• The same message when trying to delete a comment:

The action 'show' could not be found for CommentsController

• When trying to delete an article, it was not being deleted but rendering its page instead.

• The confirmation dialog was not showing when deleting neither an article nor a comment.

I have tried to restart the server as well as one of the solutions above that says to create a show method identical to the destroy method. Well, it worked fine for deleting comments but it didn't seem right to me considering the RoR DRY pattern.

I ended up realizing that the browser's extension responsible for blocking JavaScript (NoScript 11.2.9) was active and causing those weird behaviors.

In this special case, it was not related with the Rails itself but external factors.

Answer 5

add in comment model belongs_to :user if you authenticate with user and other too whatever you belongs_to...

Answer 6

I've been working through the same tutorial, and just today ran into the exact same issue as the original poster.

I didn't notice exactly when it started, but it seemed to have started somewhere in section 6, 7 or 8 (adding comments to blog, refactoring, or adding deletion of comments).

Furthermore, clicking links within the app (i.e. the 'Back' link) would spawn a new tab. Likewise, when clicking the 'Destroy' link, the browser's confirmation dialog would appear over the current tab (correct behavior), but at the same time a new browser tab would appear (incorrect) - I think this new tab behavior (a type of 'show'ing of the comment that the user is in process of deciding whether to go ahead and destroy) is what was causing the error.

After finishing the tutorial (one more section, basic authentication), I quit & re-launched Chrome, and then also quit & restarted the server (ctrl-c, then bin/rails server).

After doing this, all is well. Both the spawning extra tab behavior, as well as the spurious show action being triggered (thus causing the error) - when the destroy confirmation sheet appears - have stopped.

So it seems that this problem was simply some spurious noise - perhaps caused by something that's changed (in the rails environment?) between the time the tutorial was originally written, and when the original poster ran into this behavior (and still persisting today, July '18, with rails 5.2).

Answer 7

You can add

def show
    @article = Article.find(params[:article_id])
    @comment = @article.comments.find(params[:id])
    @comment.destroy
    redirect_to article_path(@article)
end

to your comments_controller.rb

Actually these codes are identical to those in the def destroy

Answer 8

Update: As I mentioned earlier you dont have show method in your CommentsController so you wont be able to visit the show page for any comment.

As you said you are trying to visit this url: localhost:3000/articles/2/comments/1 which is the show page for comment having id: 1 and the routes(resources :comments) is trying to take it to show action. Hence the error rightly thrown show could not be found for CommentsController.

Please remove the url from your browser and try visiting again the article show page. It will work.

Answer 9

The answer will be in your routes.rb and in the URL you are trying to call.

The URL is probably /comment/123, and the routes.rb likely has something like get 'comment/:id' => 'comment#show' in it (or a resource statement for comments).

So rails tries to show the page for a comment and you did not implement the function. The error message is saying exactly what it needs to say (you do indeed not have a .show method in your CommentsController).

If my guesses were not correct, then please post your routes.rb and the URL you are requesting.