remove AM delegating register_observer and register_interceptor to Mail and...

remove AM delegating register_observer and register_interceptor to Mail and instead implement smarter versions allowing for string class names, also added proper Railtie support with tests.
Signed-off-by: NJosé Valim <jose.valim@gmail.com>

actionmailer/lib/action_mailer/base.rb

@@ -4,6 +4,7 @@
 require 'active_support/core_ext/array/wrap'
 require 'active_support/core_ext/object/blank'
 require 'active_support/core_ext/proc'
+require 'active_support/core_ext/string/inflections'
 require 'action_mailer/log_subscriber'
 
 module ActionMailer #:nodoc:
@@ -349,9 +350,6 @@ class Base < AbstractController::Base
     helper  ActionMailer::MailHelper
     include ActionMailer::OldApi
 
-    delegate :register_observer, :to => Mail
-    delegate :register_interceptor, :to => Mail
-
     private_class_method :new #:nodoc:
 
     class_attribute :default_params
@@ -363,6 +361,32 @@ class Base < AbstractController::Base
     }.freeze
 
     class << self
+      # Register one or more Observers which will be notified when mail is delivered.
+      def register_observers(*observers)
+        observers.flatten.compact.each { |observer| register_observer(observer) }
+      end
+
+      # Register one or more Interceptors which will be called before mail is sent.
+      def register_interceptors(*interceptors)
+        interceptors.flatten.compact.each { |interceptor| register_interceptor(interceptor) }
+      end
+
+      # Register an Observer which will be notified when mail is delivered.
+      # Either a class or a string can be passed in as the Observer. If a string is passed in
+      # it will be <tt>constantize</tt>d.
+      def register_observer(observer)
+        delivery_observer = (observer.respond_to?(:delivered_email) ? observer : observer.constantize)
+        Mail.register_observer(delivery_observer)
+      end
+
+      # Register an Inteceptor which will be called before mail is sent.
+      # Either a class or a string can be passed in as the Observer. If a string is passed in
+      # it will be <tt>constantize</tt>d.
+      def register_interceptor(interceptor)
+        delivery_interceptor = (interceptor.respond_to?(:delivering_email) ? interceptor : interceptor.constantize)
+        Mail.register_interceptor(delivery_interceptor)
+      end
+
       def mailer_name
         @mailer_name ||= name.underscore
       end

actionmailer/lib/action_mailer/railtie.rb

@@ -19,13 +19,17 @@ class Railtie < Rails::Railtie
       options.stylesheets_dir ||= paths["public/stylesheets"].first
 
       # make sure readers methods get compiled
-      options.asset_path           ||= app.config.asset_path
-      options.asset_host           ||= app.config.asset_host
+      options.asset_path      ||= app.config.asset_path
+      options.asset_host      ||= app.config.asset_host
 
       ActiveSupport.on_load(:action_mailer) do
         include AbstractController::UrlFor
         extend ::AbstractController::Railties::RoutesHelpers.with(app.routes)
         include app.routes.mounted_helpers
+
+        register_interceptors(options.delete(:interceptors))
+        register_observers(options.delete(:observers))
+
         options.each { |k,v| send("#{k}=", v) }
       end
     end

actionmailer/test/base_test.rb

@@ -478,6 +478,11 @@ def self.delivered_email(mail)
     end
   end
 
+  class MySecondObserver
+    def self.delivered_email(mail)
+    end
+  end
+
   test "you can register an observer to the mail object that gets informed on email delivery" do
     ActionMailer::Base.register_observer(MyObserver)
     mail = BaseMailer.welcome
@@ -485,11 +490,31 @@ def self.delivered_email(mail)
     mail.deliver
   end
 
+  test "you can register an observer using its stringified name to the mail object that gets informed on email delivery" do
+    ActionMailer::Base.register_observer("BaseTest::MyObserver")
+    mail = BaseMailer.welcome
+    MyObserver.expects(:delivered_email).with(mail)
+    mail.deliver
+  end
+
+  test "you can register multiple observers to the mail object that both get informed on email delivery" do
+    ActionMailer::Base.register_observers("BaseTest::MyObserver", MySecondObserver)
+    mail = BaseMailer.welcome
+    MyObserver.expects(:delivered_email).with(mail)
+    MySecondObserver.expects(:delivered_email).with(mail)
+    mail.deliver
+  end
+
   class MyInterceptor
     def self.delivering_email(mail)
     end
   end
 
+  class MySecondInterceptor
+    def self.delivering_email(mail)
+    end
+  end
+
   test "you can register an interceptor to the mail object that gets passed the mail object before delivery" do
     ActionMailer::Base.register_interceptor(MyInterceptor)
     mail = BaseMailer.welcome
@@ -497,6 +522,21 @@ def self.delivering_email(mail)
     mail.deliver
   end
 
+  test "you can register an interceptor using its stringified name to the mail object that gets passed the mail object before delivery" do
+    ActionMailer::Base.register_interceptor("BaseTest::MyInterceptor")
+    mail = BaseMailer.welcome
+    MyInterceptor.expects(:delivering_email).with(mail)
+    mail.deliver
+  end
+
+  test "you can register multiple interceptors to the mail object that both get passed the mail object before delivery" do
+    ActionMailer::Base.register_interceptors("BaseTest::MyInterceptor", MySecondInterceptor)
+    mail = BaseMailer.welcome
+    MyInterceptor.expects(:delivering_email).with(mail)
+    MySecondInterceptor.expects(:delivering_email).with(mail)
+    mail.deliver
+  end
+
   test "being able to put proc's into the defaults hash and they get evaluated on mail sending" do
     mail1 = ProcMailer.welcome
     yesterday = 1.day.ago

railties/test/application/configuration_test.rb

 require "isolation/abstract_unit"
 
+class ::MyMailInterceptor
+  def self.delivering_email(email); email; end
+end
+
+class ::MyOtherMailInterceptor < ::MyMailInterceptor; end
+
+class ::MyMailObserver
+  def self.delivered_email(email); email; end
+end
+
+class ::MyOtherMailObserver < ::MyMailObserver; end
+
+
 module ApplicationTests
   class ConfigurationTest < Test::Unit::TestCase
     include ActiveSupport::Testing::Isolation
@@ -245,6 +258,58 @@ def index
       assert_equal res, last_response.body # value should be unchanged
     end
 
+    test "registers interceptors with ActionMailer" do
+      add_to_config <<-RUBY
+        config.action_mailer.interceptors = MyMailInterceptor
+      RUBY
+
+      require "#{app_path}/config/environment"
+      require "mail"
+
+      ActionMailer::Base
+
+      assert_equal [::MyMailInterceptor], ::Mail.send(:class_variable_get, "@@delivery_interceptors")
+    end
+
+    test "registers multiple interceptors with ActionMailer" do
+      add_to_config <<-RUBY
+        config.action_mailer.interceptors = [MyMailInterceptor, "MyOtherMailInterceptor"]
+      RUBY
+
+      require "#{app_path}/config/environment"
+      require "mail"
+
+      ActionMailer::Base
+
+      assert_equal [::MyMailInterceptor, ::MyOtherMailInterceptor], ::Mail.send(:class_variable_get, "@@delivery_interceptors")
+    end
+
+    test "registers observers with ActionMailer" do
+      add_to_config <<-RUBY
+        config.action_mailer.observers = MyMailObserver
+      RUBY
+
+      require "#{app_path}/config/environment"
+      require "mail"
+
+      ActionMailer::Base
+
+      assert_equal [::MyMailObserver], ::Mail.send(:class_variable_get, "@@delivery_notification_observers")
+    end
+
+    test "registers multiple observers with ActionMailer" do
+      add_to_config <<-RUBY
+        config.action_mailer.observers = [MyMailObserver, "MyOtherMailObserver"]
+      RUBY
+
+      require "#{app_path}/config/environment"
+      require "mail"
+
+      ActionMailer::Base
+
+      assert_equal [::MyMailObserver, ::MyOtherMailObserver], ::Mail.send(:class_variable_get, "@@delivery_notification_observers")
+    end
+
     test "config.action_controller.perform_caching = false" do
       make_basic_app do |app|
         app.config.action_controller.perform_caching = false