Question

I am trying out a commenting system in a way described by ryanb in https://github.com/railscasts/154-polymorphic-association/tree/master/revised/blog-after.

It uses Rails 3 nested resource routing seen in routes.rb:

resources :articles do
  resource :comments
end

Comments are loaded by parents type and id as seen in articles_controller.rb and comments_controller.rb:

class ArticlesController < ApplicationController
  ...
  def show
    @article = Article.find(params[:id])
    @commentable = @article
    @comments = @commentable.comments
    @comment = Comment.new
  end

class CommentsController < ApplicationController
  before_filter :load_commentable

  def index
    @comments = @commentable.comments
  end
  ...
private

  def load_commentable
    resource, id = request.path.split('/')[1, 2]
    @commentable = resource.singularize.classify.constantize.find(id)
  end
  ...
end

How would I go about adding a link to a comments edit or destroy actions in comments’ view template?

_comments.html.erb:

<% @comments.each do |comment| %>
  <div class="comment">
    <%= simple_format comment.content %>
    <%= link_to "Delete", comment, method: :delete %>
  </div>
<% end %>

Answer 1

With jdoes advice I looked more into the array passing and noticed routes.rb was missing an s from resources :comments. Fixed version:

  resources :articles do
    resources :comments do
    end
  end

Now the template works perfectly just by giving the link as an array.

<% @comments.each do |comment| %>
  <div class="comment">
    <%= simple_format comment.content %>
    <%= link_to "Delete", [@commentable, comment], method: :delete %>
  </div>
<% end %>