add last_updated_at field

models/comment.rb

@@ -27,21 +27,12 @@ class Comment < Content
   counter_cache :comment_thread
 
   before_destroy :delete_descendants # TODO async
-  
-  def self.hash_tree(nodes)
-    nodes.map{|node, sub_nodes| node.to_hash.merge("children" => hash_tree(sub_nodes).compact)}
-  end
-
-  def thread_title
-    comment_thread.title
-  end
 
-  def commentable
-    comment_thread.commentable
-  end
+  before_create :set_thread_last_activity_at
+  before_update :set_thread_last_activity_at
 
-  def commentable_id
-    comment_thread.commentable_id
+  def self.hash_tree(nodes)
+    nodes.map{|node, sub_nodes| node.to_hash.merge("children" => hash_tree(sub_nodes).compact)}
   end
 
   def to_hash(params={})
@@ -66,4 +57,10 @@ class Comment < Content
     end
   end
 
+private
+
+  def set_thread_last_activity_at
+    self.comment_thread.update_attributes!(last_activity_at: Time.now.utc)
+  end
+
 end

models/comment_thread.rb

@@ -14,14 +14,19 @@ class CommentThread < Content
   field :commentable_id, type: String
   field :anonymous, type: Boolean, default: false
   field :at_position_list, type: Array, default: []
+  field :last_activity_at, type: Time
 
   include Sunspot::Mongoid
   searchable do
     text :title, boost: 5.0, stored: true, more_like_this: true
     text :body, stored: true, more_like_this: true
+    text :tags do
+      tags_array.join " "
+    end
 
     time :created_at
     time :updated_at
+    time :last_activity_at
     integer :comment_count
     integer :votes_point do
       votes_point
@@ -48,6 +53,10 @@ class CommentThread < Content
   validate :tag_names_valid
   validate :tag_names_unique
 
+  before_create :set_last_activity_at
+  before_update :set_last_activity_at
+
+
   def self.new_dumb_thread(options={})
     c = self.new
     c.title = options[:title] || "title"
@@ -105,10 +114,6 @@ class CommentThread < Content
     !!(tag =~ RE_TAG)
   end
 
-  def thread_title
-    title
-  end
-
 private
 
   RE_HEADCHAR = /[a-z0-9]/
@@ -131,4 +136,8 @@ private
       errors.add :tags, "must be unique"
     end
   end
+
+  def set_last_activity_at
+    self.last_activity_at = Time.now.utc unless last_activity_at_changed? 
+  end
 end

models/observers/at_user_observer.rb

@@ -23,16 +23,27 @@ class AtUserObserver < Mongoid::Observer
 
     new_user_ids = current_user_ids - prev_user_ids
 
+    if content_type == :thread
+      thread_title = content.title
+      thread_id = content.id
+      commentable_id = content.commentable_id
+    else
+      thread_title = content.comment_thread.title
+      thread_id = content.comment_thread.id
+      commentable_id = content.comment_thread.commentable_id
+    end
+
     unless new_user_ids.empty?
 
       notification = Notification.new(
         notification_type: "at_user",
         info: {
-          content_id: content.id,
+          comment_id: (content.id if content_type == :comment),
           content_type: content_type,
-          thread_title: content.thread_title,
+          thread_title: thread_title,
+          thread_id: thread_id,
           actor_username: content.author_with_anonymity(:username),
-          commentable_id: content.commentable_id,
+          commentable_id: commentable_id,
         }
       )
       notification.actor = content.author_with_anonymity