Add Custom Fields on Topics

app/models/topic.rb

@@ -5,10 +5,12 @@ require_dependency 'rate_limiter'
 require_dependency 'text_sentinel'
 require_dependency 'text_cleaner'
 require_dependency 'archetype'
+require_dependency "concern/has_custom_fields"
 
 class Topic < ActiveRecord::Base
   include ActionView::Helpers::SanitizeHelper
   include RateLimiter::OnCreateRecord
+  include Concern::HasCustomFields
   include Trashable
   extend Forwardable
 
@@ -103,6 +105,7 @@ class Topic < ActiveRecord::Base
   attr_accessor :user_data
   attr_accessor :posters  # TODO: can replace with posters_summary once we remove old list code
   attr_accessor :topic_list
+  attr_accessor :meta_data
   attr_accessor :include_last_poster
 
   # The regular order
@@ -318,8 +321,16 @@ class Topic < ActiveRecord::Base
     topics.where("topics.id NOT IN (?)", featured_topic_ids)
   end
 
+  def meta_data=(data)
+    custom_fields.replace(data)
+  end
+
+  def meta_data
+    custom_fields
+  end
+
   def update_meta_data(data)
-    self.meta_data = (self.meta_data || {}).merge(data.stringify_keys)
+    custom_fields.update(data)
     save
   end
 
@@ -341,8 +352,7 @@ class Topic < ActiveRecord::Base
   end
 
   def meta_data_string(key)
-    return unless meta_data.present?
-    meta_data[key.to_s]
+    custom_fields[key.to_s]
   end
 
   def self.listable_count_per_day(sinceDaysAgo=30)
@@ -820,7 +830,6 @@ end
 #  archived                :boolean          default(FALSE), not null
 #  bumped_at               :datetime         not null
 #  has_summary             :boolean          default(FALSE), not null
-#  meta_data               :hstore
 #  vote_count              :integer          default(0), not null
 #  archetype               :string(255)      default("regular"), not null
 #  featured_user4_id       :integer

app/models/topic_custom_field.rb

@@ -0,0 +1,19 @@
+class TopicCustomField < ActiveRecord::Base
+  belongs_to :topic
+end
+
+# == Schema Information
+#
+# Table name: topic_custom_fields
+#
+#  id           :integer          not null, primary key
+#  topic_id     :integer          not null
+#  name         :string(256)      not null
+#  value        :text
+#  created_at   :datetime
+#  updated_at   :datetime
+#
+# Indexes
+#
+#  index_topic_custom_fields_on_topic_id_and_name  (topic_id,name)
+#

db/migrate/20140425135354_add_topic_custom_fields.rb

@@ -0,0 +1,21 @@
+class AddTopicCustomFields < ActiveRecord::Migration
+  def change
+    create_table :topic_custom_fields do |t|
+      t.integer :topic_id, null: false
+      t.string :name, limit: 256, null: false
+      t.text :value
+      t.timestamps
+    end
+
+    add_index :topic_custom_fields, [:topic_id, :name]
+
+    # migrate meta_data into custom fields
+    execute <<-SQL
+      INSERT INTO topic_custom_fields(topic_id, name, value)
+        SELECT id, (each(meta_data)).key, (each(meta_data)).value
+            FROM topics WHERE meta_data <> ''
+    SQL
+
+    remove_column :topics, :meta_data
+  end
+end

spec/models/topic_spec.rb

@@ -722,6 +722,21 @@ describe Topic do
 
       end
 
+      context 'new key' do
+        before do
+          topic.update_meta_data('other' => 'key')
+          topic.save!
+        end
+
+        it "can be loaded" do
+          Topic.find(topic.id).meta_data["other"].should == "key"
+        end
+
+        it "is in sync with custom_fields" do
+          Topic.find(topic.id).custom_fields["other"].should == "key"
+        end
+      end
+
 
     end
 
@@ -1380,7 +1395,17 @@ describe Topic do
       topic.stubs(:has_topic_embed?).returns(false)
       topic.expandable_first_post?.should be_false
     end
+  end
 
+  it "has custom fields" do
+    topic = Fabricate(:topic)
+    topic.custom_fields["a"].should == nil
 
+    topic.custom_fields["bob"] = "marley"
+    topic.custom_fields["jack"] = "black"
+    topic.save
+
+    topic = Topic.find(topic.id)
+    topic.custom_fields.should == {"bob" => "marley", "jack" => "black"}
   end
 end