no browser cache for dashboard and text editor

app/dashboard.rb

@@ -1,6 +1,7 @@
 get '/dashboard' do
   require_login
   dashboard_init
+  dont_browser_cache
 
   unless current_site.dashboard_accessed
     current_site.dashboard_accessed = true

app/site_files.rb

@@ -160,6 +160,8 @@ end
 
 get %r{\/site_files\/text_editor\/(.+)} do
   require_login
+  dont_browser_cache
+
   @filename = params[:captures].first
   extname = File.extname @filename
   @ace_mode = case extname

app_helpers.rb

@@ -112,3 +112,7 @@ def plan_pricing_button(plan_type)
     %{<a data-plan_name="#{Site::PLAN_FEATURES[plan_type.to_sym][:name]}" data-plan_type="#{plan_type}" data-plan_price="#{plan_price}" onclick="card = new Skeuocard($('#skeuocard')); return false" class="btn-Action planPricingButton">#{button_title}</a>}
   end
 end
+
+def dont_browser_cache
+  @dont_browser_cache = true
+end

views/layout.erb

@@ -23,6 +23,12 @@
     <meta name="MobileOptimized"  content="320">
     <meta name="viewport"         content="width=device-width, minimum-scale=1, initial-scale=1">
 
+    <% if @dont_browser_cache %>
+      <meta http-equiv="Cache-Control" content="no-cache, no-store, must-revalidate">
+      <meta http-equiv="Pragma" content="no-cache">
+      <meta http-equiv="Expires" content="0">
+    <% end %>
+
     <!--[if lt IE 9]>
       <script type="text/javascript" src="/js/html5.min.js"></script>
     <![endif]-->