Async actionmailer

actionmailer/lib/action_mailer/async.rb

@@ -0,0 +1,49 @@
+module ActionMailer::Async
+  def self.included(base)
+    base.extend(ClassMethods)
+  end
+
+  module ClassMethods
+    def method_missing(method_name, *args)
+      if action_methods.include?(method_name.to_s)
+        QueuedMessage.new(self, method_name, *args)
+      else
+        super
+      end
+    end
+  end
+
+  class QueuedMessage
+    delegate :to_s, :to => :actual_message
+
+    def initialize(mailer_class, method_name, *args)
+      @mailer_class = mailer_class
+      @method_name  = method_name
+      *@args        = *args
+    end
+
+    def run
+      actual_message.deliver
+    end
+
+    # Will push the message onto the Queue to be processed
+    # To force message delivery dispite async pass `true`
+    #    Emailer.welcome.deliver(true)
+    def deliver(force = false)
+      if force
+        run
+      else
+        Rails.queue << self
+      end
+    end
+
+    # The original ActionMailer message
+    def actual_message
+      @actual_message ||= @mailer_class.send(:new, @method_name, *@args).message
+    end
+
+    def method_missing(method_name, *args)
+      actual_message.send(method_name, *args)
+    end
+  end
+end

actionmailer/lib/action_mailer/base.rb

@@ -456,6 +456,14 @@ 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 Rails.queue
+      def async=(truth)
+        if truth
+          require 'action_mailer/async'
+          include ActionMailer::Async
+        end
+      end
+
     protected
 
       def set_payload_for_mail(payload, mail) #:nodoc:

actionmailer/test/base_test.rb

@@ -7,6 +7,9 @@
 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 +422,24 @@ def teardown
     assert_equal(1, BaseMailer.deliveries.length)
   end
 
+  test "delivering message asynchronously" do
+    Rails.stubs(:queue).returns(Rails::Queueing::TestQueue.new)
+    AsyncMailer.delivery_method = :test
+    AsyncMailer.deliveries.clear
+    AsyncMailer.welcome.deliver
+    assert_equal(0, AsyncMailer.deliveries.length)
+    Rails.queue.drain
+    assert_equal(1, AsyncMailer.deliveries.length)
+  end
+
+  test "forcing message delivery despite asynchronous" do
+    Rails.stubs(:queue).returns(Rails::Queueing::TestQueue.new)
+    AsyncMailer.delivery_method = :test
+    AsyncMailer.deliveries.clear
+    AsyncMailer.welcome.deliver(true)
+    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 +455,7 @@ 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/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