finish calendar route

app/controllers/people_controller.rb

     cal = Icalendar::Calendar.new
 
     @person.participants.joins(:activity).where('end > ?', 3.months.ago).each do |p|
+      next if !p.attending && params[:skipcancel]
+
       a = p.activity
       description_items = [a.description]
       orgi = a.organizer_names
 
       cal.event do |e|
         e.uid = group_activity_url a.group, a
+        e.ip_class = "PRIVATE"
         e.dtstart = a.start
         e.dtend = a.end
+
+        e.status = p.ical_attending
+
         e.summary = a.name
         e.location = a.location
+
         e.description = description_items.join "\n"
 
         e.url = group_activity_url a.group, a

app/models/participant.rb

     HUMAN_ATTENDING[self.attending]
   end
 
+  ICAL_ATTENDING = {
+    true => 'ATTENDING',
+    false => 'CANCELLED',
+    nil => 'TENTATIVE'
+  }
+
+  # @return [String]
+  #   the ICal attending response.
+  def ical_attending
+    ICAL_ATTENDING[self.attending]
+  end
+
   # TODO: Move to a more appropriate place
   # @return [String]
   #   the class for a row containing this activity.