Bust AJAX request caching

README.md

The following will prevent all future AJAX requests from being cached, regardless of which jQuery method you use ($.get, $.ajax, etc.)

$.ajaxSetup({ cache: false });

Source: http://stackoverflow.com/a/735101/83743

However, jQuery's AJAX object will follow redirects, so even if you disable caching globally the "_={timestamp}" parameter that jQuery adds to bust the browser's cache may not be forwarded with the redirect. In that case, your request can still be cached by the browser. The solution is to either make sure that special param is passed along with redirects, or to send the appropriate cache-busting response headers from the server-side code for those requests.

Reference: http://api.jquery.com/jQuery.ajax/

application_controller.rb

# app/controllers/application_controller.rb

class ApplicationController < ActionController::Base
  before_filter :set_cache_buster_for_xhr

  private 
  
  # Prevent AJAX requests/redirects from being cached
  def set_cache_buster_for_xhr
    if request.xhr?
      response.headers["Cache-Control"] = "no-cache, no-store, max-age=0, must-revalidate"
      response.headers["Pragma"] = "no-cache"
      response.headers["Expires"] = "Fri, 01 Jan 1990 00:00:00 GMT"
    end
  end
end

scripts.js

// public/javascripts/scripts.js
// A javascript file that is included in all requests

jQuery(document).ready(function($){
  // Disable caching of *all* AJAX requests
  $.ajaxSetup({ cache: false });
});