如何使用Ajax向我的Rails控制器发出POST请求？

Question

I am trying to send information from my JavaScript game-state on the front end, to my controller and then database. I'm not getting any response, and I'm not sure why.

Here's the listening event with the Ajax, containing the variable value ( score ) I want to send.

$("#link-to-hq").click(function(){
 test = $.ajax({
          type: "POST",
          url:    "/users/:id",
          data: {dollars: score},
          datatype:"html",
          async: true
        });
});

And the button it listens to:

</script>

<%= link_to "Home", user_path(@user), id: 'link-to-hq' %> 

And the route I'm trying to hit:

PATCH  /users/:id(.:format)                     users#update

Then, here's my controller:

def update
    @user = User.find(params[:id])
    new_dollars = params[:dollars]
    #store to database
    @user.dollars<<new_dollars
 end

I don't seem to be getting any feedback. Is my request or controller formulated incorrectly?

EDIT 1

I did indeed change the request, as per suggested:

$("#link-to-hq").click(function(){
  test = $.ajax({
          type: "PATCH",
          url:    "/users/<%= @user.id %>",
          data: {dollars: score},
          datatype:"html",
          async: true
        });
});

Its still unresponsive.

Heres my dev log info. There are errors:

Started PATCH "/users/0" for 127.0.0.1 at 2014-07-14 13:52:30 -0400
Processing by UsersController#update as */*
  Parameters: {"dollars"=>"1", "id"=>"0"}
  [1m[35mUser Load (0.6ms)[0m  SELECT  "users".* FROM "users"  WHERE                  "users"."remember_token" = '5b38b7021d2e00f6aecc21b29e2322d4f988c6eb' LIMIT 1
  [1m[36mUser Load (0.4ms)[0m  [1mSELECT  "users".* FROM "users"  WHERE "users"."id"    = $1 LIMIT 1[0m  [["id", 0]]
Completed 400 Bad Request in 5ms

ActionController::ParameterMissing (param is missing or the value is empty: user):
  app/controllers/users_controller.rb:85:in `user_params'
  app/controllers/users_controller.rb:66:in `update'

Answer 1

POST is for new requests.

Try:

type: "PATCH",

I believe this will also work:

type: "PUT",

Also, make sure you specify :id as an actual number.

Answer 2

To expand on beautifulcoder's accurate answer, you need to both align the type with the route you're trying to hit, and make sure you're using real numbers in the ajax URL. You've changed the URL to reference @user, but Javascript can't reference Ruby variables.

The simplest way to tackle your current issue would be to pass the Ruby variable to a data attribute in your view:

# your view
<element id="some_id" data-user_id="<%= @user.id %>"></element>

# your javascript/jquery

$("#link-to-hq").click(function(){
  var id = $('#some_id').data('user_id');
  test = $.ajax({
      type: "PATCH",
      url:    "/users/" + id,
      data: {dollars: score},
      datatype:"html",
      async: true
    });
});

If the user is the current user, and you have, or could create, a current_user helper, you can also just make the action :id independent:

# javascript/jquery
$("#link-to-hq").click(function(){
  test = $.ajax({
      type: "PATCH",
      url:    "/users/update",
      data: {dollars: score},
      datatype:"html",
      async: true
    });
});

# routes.rb
PATCH  /users/update                   users#update

#users_controller.rb
def update
  @user = current_user
  new_dollars = params[:dollars]
  #store to database
  @user.dollars<<new_dollars
end