Addded Diaspora::Likeable module. Corrected the unique index for likes to include author_id; extracted before_save callback needed for tags into Diaspora::Taggable.

app/models/comment.rb

@@ -14,6 +14,7 @@ class Comment < ActiveRecord::Base
 
   include Diaspora::Socketable
   include Diaspora::Taggable
+  include Diaspora::Likeable
 
   acts_as_taggable_on :tags
   extract_tags_from :text
@@ -25,8 +26,6 @@ class Comment < ActiveRecord::Base
   belongs_to :post, :touch => true
   belongs_to :author, :class_name => 'Person'
 
-  has_many :likes, :conditions => {:positive => true}, :dependent => :delete_all, :as => :target
-
   validates_presence_of :text, :post
   validates_length_of :text, :maximum => 2500
 
@@ -62,10 +61,4 @@ class Comment < ActiveRecord::Base
   def parent= parent
     self.post = parent
   end
-
-  # @return [Integer]
-  def update_likes_counter
-    self.likes_count = self.likes.count
-    self.save
-  end
 end

app/models/like.rb

@@ -11,7 +11,6 @@ class Like < ActiveRecord::Base
 
   xml_attr :target_type
   include Diaspora::Relayable
-
   include Diaspora::Socketable
 
   xml_attr :positive

app/models/post.rb

@@ -9,13 +9,13 @@ class Post < ActiveRecord::Base
   include Diaspora::Webhooks
   include Diaspora::Guid
 
+  include Diaspora::Likeable
+
   xml_attr :diaspora_handle
   xml_attr :public
   xml_attr :created_at
 
   has_many :comments, :dependent => :destroy
-  has_many :likes, :conditions => {:positive => true}, :dependent => :delete_all, :as => :target
-  has_many :dislikes, :conditions => {:positive => false}, :class_name => 'Like', :dependent => :delete_all, :as => :target
 
   has_many :aspect_visibilities
   has_many :aspects, :through => :aspect_visibilities
@@ -52,12 +52,6 @@ class Post < ActiveRecord::Base
     new_post
   end
 
-  # @return [Integer]
-  def update_likes_counter
-    self.likes_count = self.likes.count
-    self.save
-  end
-
   # @return Returns true if this Post will accept updates (i.e. updates to the caption of a photo).
   def mutable?
     false

app/models/status_message.rb

@@ -24,7 +24,6 @@ class StatusMessage < Post
 
   serialize :youtube_titles, Hash
 
-  before_create :build_tags
   after_create :create_mentions
 
   def text(opts = {})

db/migrate/20110707234802_likes_on_comments.rb

@@ -12,7 +12,7 @@ class LikesOnComments < ActiveRecord::Migration
         SET target_type = 'Post'
 SQL
 
-    add_index :likes, [:target_id, :target_type], :unique => true
+    add_index :likes, [:target_id, :author_id, :target_type], :unique => true
   end
 
   def self.down

db/schema.rb

@@ -123,6 +123,7 @@ ActiveRecord::Schema.define(:version => 20110707234802) do
 
   add_index "likes", ["author_id"], :name => "likes_author_id_fk"
   add_index "likes", ["guid"], :name => "index_likes_on_guid", :unique => true
+  add_index "likes", ["target_id", "author_id", "target_type"], :name => "index_likes_on_target_id_and_author_id_and_target_type", :unique => true
   add_index "likes", ["target_id"], :name => "index_likes_on_post_id"
 
   create_table "mentions", :force => true do |t|

lib/diaspora/likeable.rb

@@ -0,0 +1,20 @@
+#   Copyright (c) 2010, Diaspora Inc.  This file is
+#   licensed under the Affero General Public License version 3 or later.  See
+#   the COPYRIGHT file.
+
+module Diaspora
+  module Likeable
+    def self.included(model)
+      model.instance_eval do
+        has_many :likes, :conditions => {:positive => true}, :dependent => :delete_all, :as => :target
+        has_many :dislikes, :conditions => {:positive => false}, :class_name => 'Like', :dependent => :delete_all, :as => :target
+      end
+    end
+
+    # @return [Integer]
+    def update_likes_counter
+      self.likes_count = self.likes.count
+      self.save
+    end
+  end
+end

lib/diaspora/taggable.rb

@@ -11,6 +11,8 @@ module Diaspora
         cattr_accessor :field_with_tags
       end
       model.instance_eval do
+        before_create :build_tags
+
         def extract_tags_from sym
           self.field_with_tags = sym
         end