reimplement caching of robots.txt

app/controllers/homescreen_controller.rb

@@ -28,7 +28,6 @@
 #++
 
 class HomescreenController < ApplicationController
-
   skip_before_filter :check_if_login_required, only: [:robots]
 
   def index
@@ -43,5 +42,4 @@ class HomescreenController < ApplicationController
   def robots
     @projects = Project.active.public_projects
   end
-  caches_action :robots
 end

app/views/homescreen/robots.text.erb

@@ -27,10 +27,12 @@ See doc/COPYRIGHT.rdoc for more details.
 
 ++#%>
 User-agent: *
-<% @projects.each do |p| -%>
+<% cache @projects.cache_key(:updated_on) do %>
+  <% @projects.each do |p| -%>
 Disallow: <%= project_repository_path(p) %>
 Disallow: <%= project_work_packages_path(p) %>
 Disallow: <%= project_activity_index_path(p) %>
-<% end -%>
+  <% end -%>
+<% end %>
 Disallow: /work_packages/calendar
 Disallow: /activity