gistfile1.diff

diff --git a/app/models/topic.rb b/app/models/topic.rb
index c27a174..bcd9d5a 100644
--- a/app/models/topic.rb
+++ b/app/models/topic.rb
@@ -117,15 +117,55 @@ class Topic < ActiveRecord::Base
     replies.active.count
   end
 
+  # Public: Used by views to determine whether the index page needs to
+  # be updated.
+  #
+  # When any topic or post is updated the old cache will just be
+  # unused and eventually be removed by memcached.
+  #
+  # This will also handle users specific needs with regards to the
+  # number of topics to display per page and what page the user is
+  # currently visiting.
+  #
+  # current_site - a symbol to say whether the site is :default or
+  #                :medical
+  # current_page - params[:page] from the controller, this should be
+  #                an integer or a string representing an integer.
+  # per_page     - params[:per_page] from the controller, this should
+
   def self.index_cache_path(current_site, current_page, per_page)
     "topics/?page=#{current_page}&per_page=#{per_page}&current_site=#{current_site}##{cache_timestamp}"
   end
 
+  # Public: Used by views to determine whether the show page needs to
+  # be updated.
+  #
+  # When the topic or any of its posts are updated the old cache will
+  # just be unused and eventually be removed by memcached.
+  #
+  # This will also handle users specific needs with regards to the
+  # order of posts, how many posts to display on the page and the
+  # current page that the user is visiting.
+  #
+  # current_page - params[:page] from the controller, this should be
+  #                an integer or a string representing an integer.
+  # per_page     - params[:per_page] from the controller, this should
+  #                be an integer or a string representing an integer.
+  # posts_order  - whether the order of post retrieval is ascending or
+  #                descending. Should be a string which is either
+  #                'ASC' or 'DESC'
+  # Returns a unique string for each topic / per page / current page /
+  # order combination
+
   def show_cache_path(current_page, per_page, posts_order)
     # TODO: check if we need is_monitored?
     "forums/#{forum.id}/topics/#{id}?page=#{current_page}&per_page=#{per_page}&order=#{posts_order}##{updated_at.to_i}"
   end
 
+  # Public: Changed every time a topic or post is updated
+  #
+  # Returns an integer
+
   def self.cache_timestamp
     first(:order => "updated_at desc").updated_at.to_i
   end