From 6efc0ab802a847d040af4217ea0b7c935e2ee6bb Mon Sep 17 00:00:00 2001
From: stveep <spettitt@gmail.com>
Date: Mon, 7 May 2018 11:16:40 +0100
Subject: [PATCH] Set response headers to disable cache - to avoid back button
 emptying cart (#1213)

---
 app/controllers/application_controller.rb | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/app/controllers/application_controller.rb b/app/controllers/application_controller.rb
index e19c9bb26b..a4bdc88b8f 100644
--- a/app/controllers/application_controller.rb
+++ b/app/controllers/application_controller.rb
@@ -4,6 +4,7 @@ class ApplicationController < ActionController::Base
   protect_from_forgery
 
   prepend_before_filter :restrict_iframes
+  before_filter :set_cache_headers # Issue #1213, prevent cart emptying via cache when using back button
 
   include EnterprisesHelper
   helper CssSplitter::ApplicationHelper
@@ -152,4 +153,10 @@ class ApplicationController < ActionController::Base
     nil
   end
 
+  def set_cache_headers # https://jacopretorius.net/2014/01/force-page-to-reload-on-browser-back-in-rails.html
+    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