From 36c199ae1c9b086c102af46276adbe03ece7d079 Mon Sep 17 00:00:00 2001
From: Victor Costa <vfcosta@gmail.com>
Date: Wed, 9 Sep 2015 09:22:40 -0300
Subject: [PATCH] Add counter cache for article followers

---
 app/models/article_follower.rb                              |  2 +-
 db/migrate/20150909091347_add_followers_count_to_article.rb | 15 +++++++++++++++
 2 files changed, 16 insertions(+), 1 deletion(-)
 create mode 100644 db/migrate/20150909091347_add_followers_count_to_article.rb

diff --git a/app/models/article_follower.rb b/app/models/article_follower.rb
index 632f663..f14687a 100644
--- a/app/models/article_follower.rb
+++ b/app/models/article_follower.rb
@@ -1,5 +1,5 @@
 class ArticleFollower < ActiveRecord::Base
   attr_accessible :article_id, :person_id, :since
-  belongs_to :article
+  belongs_to :article, :counter_cache => :followers_count
   belongs_to :person
 end
diff --git a/db/migrate/20150909091347_add_followers_count_to_article.rb b/db/migrate/20150909091347_add_followers_count_to_article.rb
new file mode 100644
index 0000000..c5f3648
--- /dev/null
+++ b/db/migrate/20150909091347_add_followers_count_to_article.rb
@@ -0,0 +1,15 @@
+class AddFollowersCountToArticle < ActiveRecord::Migration
+
+  def self.up
+    add_column :articles, :followers_count, :integer, :default => 0
+    add_column :article_versions, :followers_count, :integer
+
+    execute "update articles set followers_count = (select count(*) from article_followers where article_followers.article_id = articles.id)"
+  end
+
+  def self.down
+    remove_column :article_versions, :followers_count
+    remove_column :articles, :followers_count
+  end
+
+end
--
libgit2 0.21.2