Sorting questions with nested resources using jquery - ruby-on-rails

Question

There are many questions already on this topic but I cannot seem to find anything that works. Using this railscast, I'm trying to sort a list of questions using jquery-ui but like this question my nested resources are confusing things.
I have three models: posts, comments and questions.
Post.rb:
class Post < ActiveRecord::Base
has_many :comments
has_many :questions, :through :comments
end
Comment.rb
class Comment < ActiveRecord::Base
belongs_to :post
has_many :questions
end
Question.rb
class Question < ActiveRecord::Base
belongs_to :comment
end
The list of questions I'd like to sort is on the ordered_path view (posts/:id/ordered). Here is the posts controller:
Posts_controller.rb
def ordered
#post = Post.friendly.find(params[:id])
#ordered = #post.questions.where(:hide => true).where(:recommend => true).order("position")
end
and questions_controller.rb:
def sort
params[:question].each_with_index do |id, index|
Question.update_all({position: index+1}, {id: id})
end
render nothing: true
end
I believe I've followed the railscast correctly. I've added a 'position' column to questions. I added this to the routes:
routes.rb
resources :comments do
resources :questions do
collection { post :sort }
end
end
And in my view I have this
posts/ordered.html.erb
<ul id="questions" data-update-url="<%= sort_comment_questions_path %>">
<% #ordered.each do |question| %>
<%= content_tag_for :li, question do %>
<span class="handle">[drag]</span>
<%= question.body %>
<% end %>
<% end %>
</ul>
Lastly, posts.js.coffee:
jQuery ->
$('#questions').sortable
axis: 'y'
handle: '.handle'
update: ->
$.post($(this).data('update-url'), $(this).sortable('serialize'))
My problem(s) is that I am unsure what to pass into the data-update-url (to get rid of the 'no route matches' error) or if that's even the correct path in the first place.

Answer 1

First thing in your code, change the line
#ordered = #post.questions.where(:hide => true).where(:recommend => true).order("position")
to
#ordered = #post.questions.where(:hide => true, :recommend => true).order("position")
As you typically only want one where() call if you can help it. Sometimes you will need to add one conditionally which is fine. In an if block for example.
As far as your route error, run rake routes in terminal, and you will see output of all the route methods, the params they accept, the HTTP method, and what controller#action it hits.
The important thing to note about nested resources, is the nested resource is applied to a "member" of the parent. So in your case what your two resources blocks are generating are:
GET /comments/:comment_id/questions questions#index
GET /comments/:comment_id/questions/:id questions#show
POST /comments/:comment_id/questions/sort questions#sort
So in your erb tags in the data attribute, you need to add the comment to it:
<ul id="questions" data-update-url="<%= sort_comment_questions_path(#comment) %>">
The problem though is that you are using this at the post model level, which has many comments. So what you probably want is this:
resources :comments do
resources :questions
end
resources :posts do
member do
post "sort" => "questions#sort", :as => "sort_questions"
end
end
Then in your view:
<ul id="questions" data-update-url="<%= sort_questions_post_path(#post) %>">