Forum: Ruby on Rails AJAX to change session data

Hi,
I am trying to figure out how to implement AJAX to set a session
variable when a user selects from a dropdown.  I have not used AJAX
before.

My dropdown code is:
<%= collection_select(
          :question,
           :subject_id,
           Subject.order(:title),
           :id,
           :title,
           :prompt => "Select a Subject") %>

My coffeescript is
jQuery ->
  books = $('#question_book_id').html()
  $('#question_subject_id').change ->
    alert("Set the session[subject] now!")
    subject = $('#question_subject_id :selected').text()
    ...


I assume I create a method in users_controller to change the session
variable. My question is how do I call it in the jquery code?

This seems to work...

Routes:
match '/users/update_subject', :to => 'users#update_subject', :as => 
:update_subject

jQuery:
        ...
  $.ajax(
         url: '/users/update_subject',
         data:  "subject_title=" + subject)

Controller:
def update_subject
    session[:subject] = params[:subject_title]
end

Can anyone tell me if it is OK to use a GET request (default) for this 
or do I need to specify a POST, as  I am only using this to set a 
session variable and not hitting the database?

Thanks!

Hi.
You can fixed this issue by next way:

Controller:
def update_subject
    session[:subject] = params[:subject_title]
*    render action: 'ANY_STUB_PAGE' and return *
end

This action updates session value at cookies in client side. Stub page 
will
not be visible, because incoming data will not be rendered on the 
screen,
only in the backend.