Support sending attachments

README.rst

@@ -122,7 +122,8 @@ Djrill supports most of the functionality of Django's `EmailMessage`_ and
   raise a ``ValueError`` exception when you attempt to send the message.
   (Mandrill doesn't support sending multiple html alternative parts, or any
   non-html alternatives.)
-* Djrill (currently) silently ignores all attachments on a message.
+* Djrill attempts to include a message's attachments, though Mandrill may place
+  some restrictions on allowable attachment types. (See the Mandrill docs.)
 * Djrill treats all cc and bcc recipients as if they were additional "to"
   addresses. (Mandrill does not distinguish cc, and only allows a single bcc --
   which Djrill doesn't use. *Caution:* depending on the ``preserve_recipients``

djrill/mail/backends/djrill.py

@@ -1,10 +1,13 @@
 from django.conf import settings
 from django.core.exceptions import ImproperlyConfigured
 from django.core.mail.backends.base import BaseEmailBackend
-from django.core.mail.message import sanitize_address
+from django.core.mail.message import sanitize_address, DEFAULT_ATTACHMENT_MIME_TYPE
 from django.utils import simplejson as json
 
+from base64 import b64encode
+from email.mime.base import MIMEBase
 from email.utils import parseaddr
+import mimetypes
 import requests
 
 # This backend was developed against this API endpoint.
@@ -68,6 +71,7 @@ class DjrillBackend(BaseEmailBackend):
             self._add_mandrill_options(message, msg_dict)
             if getattr(message, 'alternatives', None):
                 self._add_alternatives(message, msg_dict)
+            self._add_attachments(message, msg_dict)
         except ValueError:
             if not self.fail_silently:
                 raise
@@ -186,3 +190,39 @@ class DjrillBackend(BaseEmailBackend):
                              % mimetype)
 
         msg_dict['html'] = content
+
+    def _add_attachments(self, message, msg_dict):
+        """Extend msg_dict to include any attachments in message"""
+        if message.attachments:
+            attachments = [
+            self._make_mandrill_attachment(attachment)
+            for attachment in message.attachments
+            ]
+            if len(attachments) > 0:
+                msg_dict['attachments'] = attachments
+
+    def _make_mandrill_attachment(self, attachment):
+        """Return a Mandrill dict for an EmailMessage.attachments item"""
+        # Note that an attachment can be either a tuple of (filename, content,
+        # mimetype) or a MIMEBase object. (Also, both filename and mimetype may
+        # be missing.)
+        if isinstance(attachment, MIMEBase):
+            filename = attachment.get_filename()
+            content = attachment.get_payload(decode=True)
+            mimetype = attachment.get_content_type()
+        else:
+            (filename, content, mimetype) = attachment
+
+        # Guess missing mimetype, borrowed from
+        # django.core.mail.EmailMessage._create_attachment()
+        if mimetype is None and filename is not None:
+            mimetype, _ = mimetypes.guess_type(filename)
+        if mimetype is None:
+            mimetype = DEFAULT_ATTACHMENT_MIME_TYPE
+
+        return {
+            'type': mimetype,
+            'name': filename or "",
+            'content': b64encode(content),
+        }
+

djrill/tests/test_mandrill_send.py

@@ -1,3 +1,6 @@
+from base64 import b64encode
+from email.mime.base import MIMEBase
+
 from django.conf import settings
 from django.core import mail
 from django.core.exceptions import ImproperlyConfigured
@@ -78,6 +81,40 @@ class DjrillBackendTests(DjrillBackendMockAPITestCase):
         data = self.get_api_call_data()
         self.assertEqual(data['message']['text'], text_content)
         self.assertEqual(data['message']['html'], html_content)
+        # Don't accidentally send the html part as an attachment:
+        self.assertFalse('attachments' in data['message'])
+
+    def test_attachments(self):
+        email = mail.EmailMessage('Subject', 'Body goes here',
+            'from@example.com', ['to1@example.com'])
+
+        content1 = "* Item one\n* Item two\n* Item three"
+        email.attach(filename="test.txt", content=content1,
+            mimetype="text/plain")
+
+        # Should guess mimetype if not provided...
+        content2 = "PNG* pretend this is the contents of a png file"
+        email.attach(filename="test.png", content=content2)
+
+        # Should work with a MIMEBase object (also tests no filename)...
+        content3 = "PDF* pretend this is valid pdf data"
+        mimeattachment = MIMEBase('application', 'pdf')
+        mimeattachment.set_payload(content3)
+        email.attach(mimeattachment)
+
+        email.send()
+        data = self.get_api_call_data()
+        attachments = data['message']['attachments']
+        self.assertEqual(len(attachments), 3)
+        self.assertEqual(attachments[0]["type"], "text/plain")
+        self.assertEqual(attachments[0]["name"], "test.txt")
+        self.assertEqual(attachments[0]["content"], b64encode(content1))
+        self.assertEqual(attachments[1]["type"], "image/png") # inferred
+        self.assertEqual(attachments[1]["name"], "test.png")
+        self.assertEqual(attachments[1]["content"], b64encode(content2))
+        self.assertEqual(attachments[2]["type"], "application/pdf")
+        self.assertEqual(attachments[2]["name"], "") # none
+        self.assertEqual(attachments[2]["content"], b64encode(content3))
 
     def test_extra_header_errors(self):
         email = mail.EmailMessage('Subject', 'Body', 'from@example.com',