Asynchronous ActionMailer

Any ActionMailer class can be set to render and delier messages using
the new Rails Queue.

Some of this work was borrowed (with permission) from Nick Plante's
(zapnap) reqsue_mailer gem.

5 files changed, 66 insertions, 0 deletions

diff --git a/actionmailer/lib/action_mailer/async.rb b/actionmailer/lib/action_mailer/async.rb
new file mode 100644
index 0000000000..6f768ac286
--- /dev/null
+++ b/actionmailer/lib/action_mailer/async.rb
@@ -0,0 +1,41 @@
+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
+
+    def deliver
+      Rails.queue << self
+    end
+
+    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
diff --git a/actionmailer/lib/action_mailer/base.rb b/actionmailer/lib/action_mailer/base.rb
index 739f9a52a9..f40b85549e 100644
--- a/actionmailer/lib/action_mailer/base.rb
+++ b/actionmailer/lib/action_mailer/base.rb
@@ -456,6 +456,13 @@ module ActionMailer #:nodoc:
         super || action_methods.include?(method.to_s)
       end
 
+      def async=(truth)
+        if truth
+          require 'action_mailer/async'
+          include ActionMailer::Async
+        end
+      end
+
     protected
 
       def set_payload_for_mail(payload, mail) #:nodoc:
diff --git a/actionmailer/test/base_test.rb b/actionmailer/test/base_test.rb
index 1b2e39b3f7..fdc784029b 100644
--- a/actionmailer/test/base_test.rb
+++ b/actionmailer/test/base_test.rb
@@ -7,6 +7,9 @@ require 'active_support/time'
 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 +422,16 @@ class BaseTest < ActiveSupport::TestCase
     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 "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 +447,7 @@ class BaseTest < ActiveSupport::TestCase
   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
diff --git a/actionmailer/test/fixtures/async_mailer/welcome.erb b/actionmailer/test/fixtures/async_mailer/welcome.erb
new file mode 100644
index 0000000000..01f3f00c63
--- /dev/null
+++ b/actionmailer/test/fixtures/async_mailer/welcome.erb
@@ -0,0 +1 @@
+Welcome
\ No newline at end of file
diff --git a/actionmailer/test/mailers/async_mailer.rb b/actionmailer/test/mailers/async_mailer.rb
new file mode 100644
index 0000000000..ce601e7343
--- /dev/null
+++ b/actionmailer/test/mailers/async_mailer.rb
@@ -0,0 +1,3 @@
+class AsyncMailer < BaseMailer
+  self.async = true
+end