How to get a JavaScript variable into Ruby code

Question

I have a little problem with my ruby/rails application.

I want to get the ID from my selected item and make a query with them.

In my _form I have:

<%= f.label "Stock", for: "text" %>
<%= f.select :stock_id, @stocks_list, {},  onchange: 'ShowUser(this.value)' %>

And my JavaScript code is:

function ShowUser(str){
   alert("You select item with value: " + str);
}

I need catch 'str' value on my controller and show the information of the selected sotck dynamically (by a query).

update:

When I select a item just show the message in a pop-up and nothing else. My complete function is

function ShowUser(str)
{

    alert("You select item with value: " + str);

    JQuery.ajax( { 
        data: {valor: str},
        type: 'post',
        url: "/orders/create",
    });

}

and the console log is

Started GET "/orders/new" for 127.0.0.1 at 2014-11-25 16:54:39 -0600
Processing by OrdersController#new as HTML
Staff Load (0.2ms)  SELECT `staffs`.* FROM `staffs`
Provider Load (0.2ms)  SELECT `providers`.* FROM `providers`
Stock Load (0.2ms)  SELECT `stocks`.* FROM `stocks`
Rendered public/templates/menu.html.erb (1.0ms)
Rendered orders/_form.html.erb (6.8ms)
Rendered orders/new.html.erb within layouts/application (39.7ms)
Completed 200 OK in 273ms (Views: 268.3ms | ActiveRecord: 0.7ms)

when I select an item the console doesn't change

You have to make a request to the server. How are you making such request? — Ortiga, Nov 25 '14 at 22:03
I tried this `JQuery.ajax( { data: {valor: str}, type: 'post', url: "/orders/create", });` from this [link](http://stackoverflow.com/questions/15085236/ajax-call-pass-javascript-variable-in-rails-3) — Carlos Antonio Bulnes Domnguez, Nov 25 '14 at 22:11
Rails is server side. Javascript is client side. You need to send an Ajax request to achieve the result your after — doz87, Nov 25 '14 at 22:13
@doz87 I know that, but I don't know how to do it, it's my first rails app — Carlos Antonio Bulnes Domnguez, Nov 25 '14 at 22:16
Can you add how it isn't working for you. Add your function ShowUser and can you show what the console is responding with? — doz87, Nov 25 '14 at 22:42
I can't upload a image but chrome show this error `Uncaught ReferenceError: JQuery is not defined` when I select a item — Carlos Antonio Bulnes Domnguez, Nov 25 '14 at 23:18
jQuery (with lowercase 'j') will work better... Anyway if you do an ajax call to the server you should also make your server respond to it. Remember that once the page is in the browser, there is no "magic" conection between the browser and your rails server, so you need to make sure that you actually treat this call as a real full-fledged call, with a corresponding route and controller and a JSON view (or serializer) — rewritten, Nov 25 '14 at 23:25

score 0 · Answer 1 · answered Nov 25 '14 at 22:52

0

Maybe you should X-CSRF-Token in POST request headers?

answered Nov 25 '14 at 22:52

Yoihito

348
2
13

score 0 · Answer 2 · answered Nov 25 '14 at 23:34

The reason your request isn't working is because your using the wrong syntax. It is trying to find a variable called JQuery hence why your getting the error Uncaught ReferenceError: JQuery is not defined.

The correct syntax is either jQuery.ajax or $.ajax.

After correcting that, you should create a response within the controller that your request is pointing to to confirm in realtime that its all working. But you should see the request in your rails console.

On another note, I noticed in the comments that your using chrome and its developer console. I would highly recommend using firefox and its plugin firebug for all your debugging. I find it much better then chrome and its very easy to see errors in your code like the one thats in this code.

How to get a JavaScript variable into Ruby code

2 Answers2