Better multipart support with implicit multipart/alternative and sorting of subparts [John Long]

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@1586 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

4 files changed, 65 insertions, 5 deletions

diff --git a/actionmailer/CHANGELOG b/actionmailer/CHANGELOG
index 4338d4d3f6..c21a89e87c 100644
--- a/actionmailer/CHANGELOG
+++ b/actionmailer/CHANGELOG
@@ -1,5 +1,7 @@
 *SVN*
 
+* Better multipart support with implicit multipart/alternative and sorting of subparts [John Long]
+
 * Allow for nested parts in multipart mails #1570 [Flurin Egger]
 
 * Normalize line endings in outgoing mail bodies to "\n" #1536 [John Long]
diff --git a/actionmailer/lib/action_mailer/base.rb b/actionmailer/lib/action_mailer/base.rb
index 9a432faa32..21f4086008 100644
--- a/actionmailer/lib/action_mailer/base.rb
+++ b/actionmailer/lib/action_mailer/base.rb
@@ -106,7 +106,14 @@ module ActionMailer #:nodoc:
   #   for unit and functional testing.
   #
   # * <tt>default_charset</tt> - The default charset used for the body and to encode the subject. Defaults to UTF-8. You can also 
-  #    pick a different charset from inside a method with <tt>@charset</tt>.
+  #   pick a different charset from inside a method with <tt>@charset</tt>.
+  # * <tt>default_content_type</tt> - The default content type used for main part of the message. Defaults to "text/plain". You
+  #   can also pick a different content type from inside a method with <tt>@content_type</tt>. 
+  # * <tt>default_implicit_parts_order</tt> - When a message is built implicitly (i.e. multiple parts are assemble from templates
+  #   which specify the content type in their filenames) this variable controls how the parts are ordered. Defaults to
+  #   ["text/html", "text/enriched", "text/plain"]. Items that appear first in the array have higher priority in the mail client
+  #   and appear last in the mime encoded message. You can also pick a different order from inside a method with
+  #   <tt>@implicit_parts_order</tt>.
   class Base
     include ActionMailer::AdvAttrAccessor
     include ActionMailer::PartContainer
@@ -144,8 +151,12 @@ module ActionMailer #:nodoc:
     @@default_content_type = "text/plain"
     cattr_accessor :default_content_type
 
+    @@default_implicit_parts_order = [ "text/html", "text/enriched", "text/plain" ]
+    cattr_accessor :default_implicit_parts_order
+
     adv_attr_accessor :recipients, :subject, :body, :from, :sent_on, :headers,
-                      :bcc, :cc, :charset, :content_type, :template
+                      :bcc, :cc, :charset, :content_type, :implicit_parts_order,
+                      :template
 
     attr_reader       :mail
 
@@ -163,6 +174,7 @@ module ActionMailer #:nodoc:
       @bcc = @cc = @from = @recipients = @sent_on = @subject = nil
       @charset = @@default_charset.dup
       @content_type = @@default_content_type.dup
+      @implicit_parts_order = @@default_implicit_parts_order.dup
       @template = method_name
       @parts = []
       @headers = {}
@@ -184,6 +196,10 @@ module ActionMailer #:nodoc:
               :disposition => "inline", :charset => charset,
               :body => render_message(File.basename(path).split(".")[0..-2].join('.'), @body))
           end
+          unless @parts.empty?
+            @content_type = "multipart/alternative"
+            @parts = sort_parts(@parts, @implicit_parts_order)
+          end
         end
 
         # Then, if there were such templates, we check to see if we ought to
@@ -235,6 +251,35 @@ module ActionMailer #:nodoc:
         ActionView::Base.new(template_path, assigns, self)
       end
 
+      def sort_parts(parts, order = [])
+        order = order.collect { |s| s.downcase }
+
+        parts = parts.sort do |a, b|
+          a_ct = a.content_type.downcase
+          b_ct = b.content_type.downcase
+
+          a_in = order.include? a_ct
+          b_in = order.include? b_ct
+
+          s = case
+          when a_in && b_in
+            order.index(a_ct) <=> order.index(b_ct)
+          when a_in
+            -1
+          when b_in
+            1
+          else
+            a_ct <=> b_ct
+          end
+
+          # reverse the ordering because parts that come last are displayed
+          # first in mail clients
+          (s * -1)
+        end
+
+        parts
+      end
+
       def create_mail
         m = TMail::Mail.new
 
diff --git a/actionmailer/test/fixtures/test_mailer/implicitly_multipart_example.text.yaml.rhtml b/actionmailer/test/fixtures/test_mailer/implicitly_multipart_example.text.yaml.rhtml
new file mode 100644
index 0000000000..c14348c770
--- /dev/null
+++ b/actionmailer/test/fixtures/test_mailer/implicitly_multipart_example.text.yaml.rhtml
@@ -0,0 +1 @@
+yaml to: <%= @recipient %>
\ No newline at end of file
diff --git a/actionmailer/test/mail_service_test.rb b/actionmailer/test/mail_service_test.rb
index 01b71801b8..85fe3ad69b 100755
--- a/actionmailer/test/mail_service_test.rb
+++ b/actionmailer/test/mail_service_test.rb
@@ -111,12 +111,13 @@ class TestMailer < ActionMailer::Base
       :body => "123456789"
   end
 
-  def implicitly_multipart_example(recipient)
+  def implicitly_multipart_example(recipient, order = nil)
     @recipients = recipient
     @subject    = "multipart example"
     @from       = "test@example.com"
     @sent_on    = Time.local 2004, 12, 12
     @body       = { "recipient" => recipient }
+    @implicit_parts_order = order unless order.nil?
   end
 
   def html_mail(recipient)
@@ -551,11 +552,22 @@ EOF
 
   def test_implicitly_multipart_messages
     mail = TestMailer.create_implicitly_multipart_example(@recipient)
-    assert_equal 2, mail.parts.length
-    assert_equal "text/html", mail.parts[0].content_type
+    assert_equal 3, mail.parts.length
+    assert_equal "multipart/alternative", mail.content_type
+    assert_equal "text/yaml", mail.parts[0].content_type
     assert_equal "utf-8", mail.parts[0].sub_header("content-type", "charset")
     assert_equal "text/plain", mail.parts[1].content_type
     assert_equal "utf-8", mail.parts[1].sub_header("content-type", "charset")
+    assert_equal "text/html", mail.parts[2].content_type
+    assert_equal "utf-8", mail.parts[2].sub_header("content-type", "charset")
+  end
+
+  def test_implicitly_multipart_messages_with_custom_order
+    mail = TestMailer.create_implicitly_multipart_example(@recipient, ["text/yaml", "text/plain"])
+    assert_equal 3, mail.parts.length
+    assert_equal "text/html", mail.parts[0].content_type
+    assert_equal "text/plain", mail.parts[1].content_type
+    assert_equal "text/yaml", mail.parts[2].content_type
   end
 
   def test_html_mail