Tidy up ActionMailer rendering logic to take advantage of view path cache instead of using file system lookups

2 files changed, 13 insertions, 2 deletions

diff --git a/actionpack/lib/action_view/base.rb b/actionpack/lib/action_view/base.rb
index bdcb1dc246..ad59d92086 100644
--- a/actionpack/lib/action_view/base.rb
+++ b/actionpack/lib/action_view/base.rb
@@ -300,6 +300,8 @@ module ActionView #:nodoc:
     #   # => 'users/legacy.rhtml'
     #
     def pick_template(template_path)
+      return template_path if template_path.respond_to?(:render)
+
       path = template_path.sub(/^\//, '')
       if m = path.match(/(.*)\.(\w+)$/)
         template_file_name, template_file_extension = m[1], m[2]
@@ -343,7 +345,8 @@ module ActionView #:nodoc:
           ActiveSupport::Deprecation.warn("use_full_path option has been deprecated and has no affect.", caller)
         end
 
-        if defined?(ActionMailer) && defined?(ActionMailer::Base) && controller.is_a?(ActionMailer::Base) && !template_path.include?("/")
+        if defined?(ActionMailer) && defined?(ActionMailer::Base) && controller.is_a?(ActionMailer::Base) &&
+            template_path.is_a?(String) && !template_path.include?("/")
           raise ActionViewError, <<-END_ERROR
   Due to changes in ActionMailer, you need to provide the mailer_name along with the template name.
 
diff --git a/actionpack/lib/action_view/template.rb b/actionpack/lib/action_view/template.rb
index b281ff61f2..5dc6708431 100644
--- a/actionpack/lib/action_view/template.rb
+++ b/actionpack/lib/action_view/template.rb
@@ -22,6 +22,14 @@ module ActionView #:nodoc:
     end
     memoize :format_and_extension
 
+    def multipart?
+      format && format.include?('.')
+    end
+
+    def content_type
+      format.gsub('.', '/')
+    end
+
     def mime_type
       Mime::Type.lookup_by_extension(format) if format
     end
@@ -84,7 +92,7 @@ module ActionView #:nodoc:
       #   [base_path, name, format, extension]
       def split(file)
         if m = file.match(/^(.*\/)?([^\.]+)\.?(\w+)?\.?(\w+)?\.?(\w+)?$/)
-          if m[5] # Mulipart formats
+          if m[5] # Multipart formats
             [m[1], m[2], "#{m[3]}.#{m[4]}", m[5]]
           elsif m[4] # Single format
             [m[1], m[2], m[3], m[4]]