Fix side_bar.

In the case of tags, take the uri instead of controller name

app/helpers/application_helper.rb

@@ -83,7 +83,7 @@ module ApplicationHelper
   end
   
   def active_for_action(controller_name, action_name)
-    (controller.controller_name.eql?(controller_name) && controller.action_name.eql?(action_name)) ? 'active' : nil
+    ((controller.controller_name.eql?(controller_name) || request.fullpath.eql?(controller_name)) && controller.action_name.eql?(action_name)) ? 'active' : nil
   end
 
   def sortable(column)