Question

I have some javascript that displays some data from my database on my webpage. I also have a button that when the user clicks it some logic occurs in the controllers and then I want to have the data displayed changed. However, at the momment when they click the button nothing happens (page is not reloaded). Could you guys help me set that up? Here is what I have so far:

controller:

class QtlsController < ApplicationController
 require 'json'
 require 'uri'
 $rollback = nil
 def index
   logger.debug "\nrollback is: #{$rollback}\n"
   render "index"
 end
 def rollback
   $rollback = params[:version].gsub(/"/,'')
   redirect_to :action => :index
 end
end

view:

  <%- if $rollback.nil? %>
     generates one type of table
  <%- else %>
     generates another type of table
  <%- end %>
  ...some other logic and buttons etc...
  jQuery(function() {
            jQuery( "#rollback").button();
            jQuery( "#rollback").click(function() {
                    var version = getSelectedText('version_selector');
                    jQuery.ajax({
                            type: "POST",
                            headers: {
                                    'X-Transaction': 'POST Example',
                                    'X-CSRF-Token': jQuery('meta[name="csrftoken"]').attr('content')
                            },
                            url: "/qtls/rollback",
                            data: {version: JSON.stringify(version) },
                            dataType: 'json',
                            sucess: function() { alert("Success! Rollbacked"); }
                    });
            });

Here is what is in log files when I go to the page and when I click the rollback button:

 Started GET "/qtls" for 10.64.229.59 at Tue Jul 17 16:48:52 -0500 2012
 Processing by QtlsController#index as HTML
 rollback is: 
 ROLLBACK IS NIL!!!
   Qtl Load (2.0ms)  SELECT `qtls`.* FROM `qtls` 
   Rendered qtls/index.html.erb within layouts/application (404.8ms)
   Rendered shared/_user_nav.html.erb (1.3ms)
   Rendered shared/_nav.html.erb (1.3ms)
   Rendered shared/_footer.html.erb (0.6ms)
 Completed 200 OK in 544ms (Views: 540.9ms | ActiveRecord: 2.0ms)
 Started POST "/qtls/rollback" for 10.64.229.59 at Tue Jul 17 16:48:57 -0500 2012
 Processing by QtlsController#rollback as JSON
   Parameters: {"version"=>"\"test1\""}
 Redirected to http://10.10.136.244:4000/qtls
 Completed 302 Found in 3ms (ActiveRecord: 0.0ms)
 Started GET "/qtls" for 10.64.229.59 at Tue Jul 17 16:48:58 -0500 2012
 Processing by QtlsController#index as JSON
 rollback is: test1
   Rendered qtls/index.html.erb within layouts/application (37.7ms)
   Rendered shared/_user_nav.html.erb (3.3ms)
   Rendered shared/_nav.html.erb (4.3ms)
   Rendered shared/_footer.html.erb (2.0ms)
 Completed 200 OK in 99ms (Views: 97.4ms | ActiveRecord: 0.0ms)

Answer 1

it’s a reaaaaaally bad style to use global variables like $rollback!

if you want to store user-data use your session-object.

use the jquery-rails gem to integrate with jQuery in your views and then use the :remote => :true in your form, so that rails can handle the form-submission.