# Copyright (C) 2007 Canonical Ltd
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
"""A convenience class around email.Message and email.MIMEMultipart."""
from email import (
Header,
Message,
MIMEMultipart,
MIMEText,
Utils,
)
from bzrlib import __version__
from bzrlib.osutils import safe_unicode
from bzrlib.smtp_connection import SMTPConnection
class EmailMessage(object):
"""An email message.
The constructor needs an origin address, a destination address or addresses
and a subject, and accepts a body as well. Add additional parts to the
message with add_inline_attachment(). Retrieve the entire formatted message
with as_string().
Headers can be accessed with get() and msg[], and modified with msg[] =.
"""
def __init__(self, from_address, to_address, subject, body=None):
"""Create an email message.
:param from_address: The origin address, to be put on the From header.
:param to_address: The destination address of the message, to be put in
the To header. Can also be a list of addresses.
:param subject: The subject of the message.
:param body: If given, the body of the message.
All four parameters can be unicode strings or byte strings, but for the
addresses and subject byte strings must be encoded in UTF-8. For the
body any byte string will be accepted; if it's not ASCII or UTF-8,
it'll be sent with charset=8-bit.
"""
self._headers = {}
self._body = body
self._parts = []
if isinstance(to_address, basestring):
to_address = [ to_address ]
to_addresses = []
for addr in to_address:
to_addresses.append(self.address_to_encoded_header(addr))
self._headers['To'] = ', '.join(to_addresses)
self._headers['From'] = self.address_to_encoded_header(from_address)
self._headers['Subject'] = Header.Header(safe_unicode(subject))
self._headers['User-Agent'] = 'Bazaar (%s)' % _bzrlib_version
def add_inline_attachment(self, body, filename=None, mime_subtype='plain'):
"""Add an inline attachment to the message.
:param body: A text to attach. Can be an unicode string or a byte
string, and it'll be sent as ascii, utf-8, or 8-bit, in that
preferred order.
:param filename: The name for the attachment. This will give a default
name for email programs to save the attachment.
:param mime_subtype: MIME subtype of the attachment (eg. 'plain' for
text/plain [default]).
The attachment body will be displayed inline, so do not use this
function to attach binary attachments.
"""
# add_inline_attachment() has been called, so the message will be a
# MIMEMultipart; add the provided body, if any, as the first attachment
if self._body is not None:
self._parts.append((self._body, None, 'plain'))
self._body = None
self._parts.append((body, filename, mime_subtype))
def as_string(self, boundary=None):
"""Return the entire formatted message as a string.
:param boundary: The boundary to use between MIME parts, if applicable.
Used for tests.
"""
if not self._parts:
msgobj = Message.Message()
if self._body is not None:
body, encoding = self.string_with_encoding(self._body)
msgobj.set_payload(body, encoding)
else:
msgobj = MIMEMultipart.MIMEMultipart()
if boundary is not None:
msgobj.set_boundary(boundary)
for body, filename, mime_subtype in self._parts:
body, encoding = self.string_with_encoding(body)
payload = MIMEText.MIMEText(body, mime_subtype, encoding)
if filename is not None:
content_type = payload['Content-Type']
content_type += '; name="%s"' % filename
payload.replace_header('Content-Type', content_type)
payload['Content-Disposition'] = 'inline'
msgobj.attach(payload)
# sort headers here to ease testing
for header, value in sorted(self._headers.items()):
msgobj[header] = value
return msgobj.as_string()
__str__ = as_string
def get(self, header, failobj=None):
"""Get a header from the message, returning failobj if not present."""
return self._headers.get(header, failobj)
def __getitem__(self, header):
"""Get a header from the message, returning None if not present.
This method intentionally does not raise KeyError to mimic the behavior
of __getitem__ in email.Message.
"""
return self._headers.get(header, None)
def __setitem__(self, header, value):
return self._headers.__setitem__(header, value)
@staticmethod
def send(config, from_address, to_address, subject, body, attachment=None,
attachment_filename=None, attachment_mime_subtype='plain'):
"""Create an email message and send it with SMTPConnection.
:param config: config object to pass to SMTPConnection constructor.
See EmailMessage.__init__() and EmailMessage.add_inline_attachment()
for an explanation of the rest of parameters.
"""
msg = EmailMessage(from_address, to_address, subject, body)
if attachment is not None:
msg.add_inline_attachment(attachment, attachment_filename,
attachment_mime_subtype)
SMTPConnection(config).send_email(msg)
@staticmethod
def address_to_encoded_header(address):
"""RFC2047-encode an address if necessary.
:param address: An unicode string, or UTF-8 byte string.
:return: A possibly RFC2047-encoded string.
"""
# Can't call Header over all the address, because that encodes both the
# name and the email address, which is not permitted by RFCs.
user, email = Utils.parseaddr(address)
if not user:
return email
else:
return Utils.formataddr((str(Header.Header(safe_unicode(user))),
email))
@staticmethod
def string_with_encoding(string_):
"""Return a str object together with an encoding.
:param string_: A str or unicode object.
:return: A tuple (str, encoding), where encoding is one of 'ascii',
'utf-8', or '8-bit', in that preferred order.
"""
# Python's email module base64-encodes the body whenever the charset is
# not explicitly set to ascii. Because of this, and because we want to
# avoid base64 when it's not necessary in order to be most compatible
# with the capabilities of the receiving side, we check with encode()
# and decode() whether the body is actually ascii-only.
if isinstance(string_, unicode):
try:
return (string_.encode('ascii'), 'ascii')
except UnicodeEncodeError:
return (string_.encode('utf-8'), 'utf-8')
else:
try:
string_.decode('ascii')
return (string_, 'ascii')
except UnicodeDecodeError:
try:
string_.decode('utf-8')
return (string_, 'utf-8')
except UnicodeDecodeError:
return (string_, '8-bit')
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