Allow to add subscribers through Railtie.

railties/lib/rails.rb

@@ -15,6 +15,7 @@
 require 'rails/paths'
 require 'rails/configuration'
 require 'rails/deprecation'
+require 'rails/subscriber'
 require 'rails/ruby_version_check'
 
 # For Ruby 1.8, this initialization sets $KCODE to 'u' to enable the

railties/lib/rails/plugin.rb

@@ -53,6 +53,7 @@ def load_tasks
       ActionController::Base.view_paths.concat ["#{path}/app/views"] if File.directory?("#{path}/app/views")
     end
 
+    # TODO Isn't it supposed to be :after => "action_controller.initialize_routing" ?
     initializer :add_routing_file, :after => :initialize_routing do |app|
       routing_file = "#{path}/config/routes.rb"
       if File.exist?(routing_file)

railties/lib/rails/railtie.rb

@@ -25,6 +25,10 @@ def self.config
       Configuration.default
     end
 
+    def self.subscriber(subscriber)
+      Rails::Subscriber.add(plugin_name, subscriber)
+    end
+
     def self.rake_tasks(&blk)
       @rake_tasks ||= []
       @rake_tasks << blk if blk

railties/test/plugins/configuration_test.rb

@@ -32,5 +32,14 @@ class MyApp < Rails::Application
       assert_equal "hello", MyApp.config.foo.greetings
       assert_equal "bar",   MyApp.config.foo.bar
     end
+
+    test "plugin can add subscribers" do
+      begin
+        class Foo < Rails::Railtie; subscriber(Rails::Subscriber.new); end
+        assert_kind_of Rails::Subscriber, Rails::Subscriber.subscribers[:foo]
+      ensure
+        Rails::Subscriber.subscribers.clear
+      end
+    end
   end
 end