Async actionmailer

actionmailer/CHANGELOG.md

@@ -2,6 +2,8 @@
 
 * Raise an `ActionView::MissingTemplate` exception when no implicit template could be found. *Damien Mathieu*
 
+* Asynchronously send messages via the Rails Queue *Brian Cardarella*
+
 ## Rails 3.2.5 (Jun 1, 2012) ##
 
 *   No changes.

actionmailer/lib/action_mailer/async.rb

@@ -0,0 +1,39 @@
+require 'delegate'
+
+module ActionMailer::Async
+  def method_missing(method_name, *args)
+    if action_methods.include?(method_name.to_s)
+      QueuedMessage.new(queue, self, method_name, *args)
+    else
+      super
+    end
+  end
+
+  def queue
+    Rails.queue
+  end
+
+  class QueuedMessage < ::Delegator
+    attr_reader :queue
+
+    def initialize(queue, mailer_class, method_name, *args)
+      @queue        = queue
+      @mailer_class = mailer_class
+      @method_name  = method_name
+      @args         = args
+    end
+
+    def __getobj__
+      @actual_message ||= @mailer_class.send(:new, @method_name, *@args).message
+    end
+
+    def run
+      __getobj__.deliver
+    end
+
+    # Will push the message onto the Queue to be processed
+    def deliver
+      @queue << self
+    end
+  end
+end

actionmailer/lib/action_mailer/base.rb

@@ -456,6 +456,18 @@ def respond_to?(method, include_private = false) #:nodoc:
         super || action_methods.include?(method.to_s)
       end
 
+      # Will force ActionMailer to push new messages to the queue defined
+      # in the ActionMailer class when set to true
+      #
+      #   class WelcomeMailer < ActionMailer::Base
+      #     self.async = true
+      def async=(truth)
+        if truth
+          require 'action_mailer/async'
+          extend ActionMailer::Async
+        end
+      end
+
     protected
 
       def set_payload_for_mail(payload, mail) #:nodoc:

actionmailer/test/base_test.rb

@@ -7,6 +7,8 @@
 require 'mailers/base_mailer'
 require 'mailers/proc_mailer'
 require 'mailers/asset_mailer'
+require 'mailers/async_mailer'
+require 'rails/queueing'
 
 class BaseTest < ActiveSupport::TestCase
   def teardown
@@ -419,6 +421,26 @@ def teardown
     assert_equal(1, BaseMailer.deliveries.length)
   end
 
+  def stub_queue(klass, queue)
+    Class.new(klass) {
+      extend Module.new {
+        define_method :queue do
+          queue
+        end
+      }
+    }
+  end
+
+  test "delivering message asynchronously" do
+    testing_queue = Rails::Queueing::TestQueue.new
+    AsyncMailer.delivery_method = :test
+    AsyncMailer.deliveries.clear
+    stub_queue(AsyncMailer, testing_queue).welcome.deliver
+    assert_equal(0, AsyncMailer.deliveries.length)
+    testing_queue.drain
+    assert_equal(1, AsyncMailer.deliveries.length)
+  end
+
   test "calling deliver, ActionMailer should yield back to mail to let it call :do_delivery on itself" do
     mail = Mail::Message.new
     mail.expects(:do_delivery).once
@@ -434,6 +456,7 @@ def teardown
   end
 
   test "should raise if missing template in implicit render" do
+    BaseMailer.deliveries.clear
     assert_raises ActionView::MissingTemplate do
       BaseMailer.implicit_different_template('missing_template').deliver
     end

actionmailer/test/fixtures/async_mailer/welcome.erb

@@ -0,0 +1 @@
+Welcome

actionmailer/test/mailers/async_mailer.rb

@@ -0,0 +1,3 @@
+class AsyncMailer < BaseMailer
+  self.async = true
+end

railties/CHANGELOG.md

@@ -39,6 +39,9 @@
 
 *   Rails::Plugin has gone. Instead of adding plugins to vendor/plugins use gems or bundler with path or git dependencies. *Santiago Pastorino*
 
+*   Set config.action_mailer.async = true to turn on asynchronous
+    message delivery *Brian Cardarella*
+
 
 ## Rails 3.2.2 (March 1, 2012) ##
 

railties/lib/rails/generators/rails/app/templates/config/application.rb

@@ -67,5 +67,8 @@ class Application < Rails::Application
     # Version of your assets, change this if you want to expire all your assets.
     config.assets.version = '1.0'
 <% end -%>
+
+    # Enable app-wide asynchronous ActionMailer
+    # config.action_mailer.async = true
   end
 end