尝试通过AJAX进行发布时出现Rails“无路线匹配”错误

Question

I am building a rails app that lets users vote on questions and answers, which are nested:

This code works as intended to let users vote up an answer:

<%= link_to raw('<i class="icon-2x icon-chevron-up"></i>'), vote_question_answer_path(@question, answer, :type => :up), :method => :post %>

but this code, which should do the same thing via ajax:

<%= link_to raw('<i class="icon-2x icon-chevron-up"></i>'), vote_question_answer_path(@question, answer, :type => :up), :remote => true, :method => :post %>

records the vote correctly, but then gives the following error:

ActionController::RoutingError at /questions/fugiat-nulla-blue-bottle-raw-denim-fap-sint-butcher-ethical-cosby-sweater-thundercats-distillery-laboris-tofu/answers/6/vote=========================================================================================================================================================================> No route matches {:action=>"vote", :controller=>"answers", :type=>:up, :question_id=>nil, :id=>#<Answer id: 6, body: "Ullamco Pinterest food truck incididunt trust fund,...", user_id: 1, question_id: 10, created_at: "2013-09-10 22:20:40", updated_at: "2013-09-10 22:20:40">}app/views/shared/_vote_answer_arrows.html.erb, line 6

I'm confused - aren't the two posting to the same route? Why is one working and the other giving a routing error?

I believe that the problem is related to the nested routes, because I have nearly identical code for the questions, and the AJAX route works there.

EDIT: As requested, here are the relevant routes:

resources :questions do
  member { post :vote }
  resources :answers do
    member { post :vote }
  end
end

And the respond_to do |format|

respond_to do |format|
  format.html{ redirect_to :back, :flash => { :success => 'Thank you for voting!' }}
  format.js {}
end

Here is the AJAX error message/URL from firebug:

"NetworkError: 500 Internal Server Error - http://localhost:3000/questions/fugiat-nulla-blue-bottle-raw-denim-fap-sint-butcher-ethical-cosby-sweater-thundercats-distillery-laboris-tofu/answers/5/vote?type=down"

And here is AJAX params from firebug (This looks very wrong to me, so I am not sure if it is the source of the problem or just me being unfamiliar with firebug:

type    down

And here is a successful non-AJAX request's parameters from the server output:

Parameters: {"authenticity_token"=>"X3Dg3TSZ8blMNTT1Zce2R0A1rtZI93ViFJNsjOP145w=", "type"=>"up", "question_id"=>"fugiat-nulla-blue-bottle-raw-denim-fap-sint-butcher-ethical-cosby-sweater-thundercats-distillery-laboris-tofu", "id"=>"3"}

Answer 1

As I mentioned in the comments above, this turned out to be a simple controller issue.

In my controller, I had not defined @question. This was not a problem until I turned the request into ajax and needed the variable to render the partials in my javascript.

I added

@question = Question.find(params[:question_id])

to the controller, and it fixed the problem.

Answer 2

In your controller do you have a respond_to do |format| block?

You should have something like...

respond_to do |format|
  if something_saves or whatever
    format.html { redirect_to random_path, notice: 'Vote was casted.' }
    format.json { render :json => { :voteCasted => true } }
  else
    format.html { render :nothing }
  end
end

The main line there is the...

format.json { render :json => { :voteCasted => true } }

At the moment it sounds like you're missing responding to the JSON format. Which is why the HTML version is working fine and the AJAX (JSON) method is not.