handler.rb in rack-tracker-1.7.0

- old
+ new

@@ -36,10 +36,15 @@
   def render
     Tilt.new(File.join(File.dirname(__FILE__), handler_name, 'template', "#{handler_name}.erb") ).render(self)
   end
 
   def inject(response)
+    # default to not inject this tracker if the DNT HTTP header is set
+    # if the DO_NOT_RESPECT_DNT_HEADER config is set the DNT header is ignored :( - please do respect the DNT header!
+    if self.dnt_header_opt_out? && !self.options.has_key?(:DO_NOT_RESPECT_DNT_HEADER)
+      return response
+    end
     # Sub! is enough, in well formed html there's only one head or body tag.
     # Block syntax need to be used, otherwise backslashes in input will mess the output.
     # @see http://stackoverflow.com/a/4149087/518204 and https://github.com/railslove/rack-tracker/issues/50
     response.sub! %r{</#{self.position}>} do |m|
       self.render << m.to_s
@@ -66,9 +71,14 @@
         if option_value = value.respond_to?(:call) ? value.call(env) : value
           tracker_options[tracker_option_key(key)] = tracker_option_value(option_value)
         end
       end
     end
+  end
+
+  # the request has set the DO NOT TRACK (DNT) and has opted to get not tracked (DNT=1)
+  def dnt_header_opt_out?
+    self.env['HTTP_DNT'] && self.env['HTTP_DNT'].to_s == '1'
   end
 
   private
 
   # Transformations to be applied to tracker option keys.