Initial commit

webservice/lib/utils/emails.py

@@ -0,0 +1,84 @@
+import os.path
+import re
+import mimetypes
+
+from email.mime.base import MIMEBase
+from django.core.mail import EmailMultiAlternatives, SafeMIMEMultipart
+from django.conf import settings
+
+# Source: https://djangosnippets.org/snippets/2215/
+class EmailMultiRelated(EmailMultiAlternatives):
+    """
+    A version of EmailMessage that makes it easy to send multipart/related
+    messages. For example, including text and HTML versions with inline images.
+    """
+    related_subtype = 'related'
+
+    def __init__(self, subject='', body='', from_email=None, to=None, bcc=None,
+            connection=None, attachments=None, headers=None, alternatives=None):
+        # self.related_ids = []
+        self.related_attachments = []
+        super(EmailMultiRelated, self).__init__(subject, body, from_email, to, bcc, connection, attachments, headers, alternatives)
+
+    def attach_related(self, filename=None, content=None, mimetype=None):
+        """
+        Attaches a file with the given filename and content. The filename can
+        be omitted and the mimetype is guessed, if not provided.
+
+        If the first parameter is a MIMEBase subclass it is inserted directly
+        into the resulting message attachments.
+        """
+        if isinstance(filename, MIMEBase):
+            assert content == mimetype == None
+            self.related_attachments.append(filename)
+        else:
+            assert content is not None
+            self.related_attachments.append((filename, content, mimetype))
+
+    def attach_related_file(self, path, mimetype=None):
+        """Attaches a file from the filesystem."""
+        filename = os.path.basename(path)
+        content = open(path, 'rb').read()
+        if mimetype is None:
+            mimetypes.init()
+            mimetype = mimetypes.guess_type(filename)[0]
+        self.attach_related(filename, content, mimetype)
+
+    def _create_message(self, msg):
+        return self._create_attachments(self._create_related_attachments(self._create_alternatives(msg)))
+
+    def _create_alternatives(self, msg):
+        for i, (content, mimetype) in enumerate(self.alternatives):
+            if mimetype == 'text/html':
+                for filename, _, _ in self.related_attachments:
+                    content = re.sub(r'(?<!cid:)%s' % re.escape(filename), 'cid:%s' % filename, content)
+                self.alternatives[i] = (content, mimetype)
+
+        return super(EmailMultiRelated, self)._create_alternatives(msg)
+
+    def _create_related_attachments(self, msg):
+        encoding = self.encoding or settings.DEFAULT_CHARSET
+        if self.related_attachments:
+            body_msg = msg
+            msg = SafeMIMEMultipart(_subtype=self.related_subtype, encoding=encoding)
+            if self.body:
+                msg.attach(body_msg)
+            for related in self.related_attachments:
+                msg.attach(self._create_related_attachment(*related))
+        return msg
+
+    def _create_related_attachment(self, filename, content, mimetype=None):
+        """
+        Convert the filename, content, mimetype triple into a MIME attachment
+        object. Adjust headers to use Content-ID where applicable.
+        Taken from http://code.djangostudy.com/ticket/4771
+        """
+        attachment = super(EmailMultiRelated, self)._create_attachment(filename, content, mimetype)
+        if filename:
+            mimetype = attachment['Content-Type']
+            del(attachment['Content-Type'])
+            del(attachment['Content-Disposition'])
+            attachment.add_header('Content-Disposition', 'inline', filename=filename)
+            attachment.add_header('Content-Type', mimetype, name=filename)
+            attachment.add_header('Content-ID', '<%s>' % filename)
+        return attachment