Add subtype to topics to classify private messages

lib/topic_subtype.rb

@@ -0,0 +1,52 @@
+class TopicSubtype
+  include ActiveModel::Serialization
+
+  attr_accessor :id, :options
+
+  def initialize(id, options)
+    @id = id
+    @options = options
+  end
+
+  def attributes
+    {'id' => @id,
+     'options' => @options}
+  end
+
+  def self.list
+    return [] unless @archetypes.present?
+    @archetypes.values
+  end
+
+  def self.user_to_user
+    'user_to_user'
+  end
+
+  def self.system_message
+    'system_message'
+  end
+
+  def self.moderator_warning
+    'moderator_warning'
+  end
+
+  def self.notify_moderators
+    'notify_moderators'
+  end
+
+  def self.notify_user
+    'notify_user'
+  end
+
+  def self.register(name, options={})
+    @subtypes ||= {}
+    @subtypes[name] = TopicSubtype.new(name, options)
+  end
+
+  register 'user_to_user'
+  register 'system_message'
+  register 'moderator_warning'
+  register 'notify_moderators'
+  register 'notify_user'
+
+end