639 lines
23 KiB
Python
639 lines
23 KiB
Python
# Copyright (C) 2001,2002 Python Software Foundation
|
||
# Author: barry@zope.com (Barry Warsaw)
|
||
|
||
"""Basic message object for the email package object model.
|
||
"""
|
||
|
||
import re
|
||
import warnings
|
||
from cStringIO import StringIO
|
||
from types import ListType, StringType
|
||
|
||
# Intrapackage imports
|
||
import Errors
|
||
import Utils
|
||
import Charset
|
||
|
||
SEMISPACE = '; '
|
||
|
||
# Regular expression used to split header parameters. BAW: this may be too
|
||
# simple. It isn't strictly RFC 2045 (section 5.1) compliant, but it catches
|
||
# most headers found in the wild. We may eventually need a full fledged
|
||
# parser eventually.
|
||
paramre = re.compile(r'\s*;\s*')
|
||
# Regular expression that matches `special' characters in parameters, the
|
||
# existance of which force quoting of the parameter value.
|
||
tspecials = re.compile(r'[ \(\)<>@,;:\\"/\[\]\?=]')
|
||
|
||
|
||
|
||
# Helper function
|
||
def _formatparam(param, value=None, quote=1):
|
||
"""Convenience function to format and return a key=value pair.
|
||
|
||
Will quote the value if needed or if quote is true.
|
||
"""
|
||
if value is not None and len(value) > 0:
|
||
# BAW: Please check this. I think that if quote is set it should
|
||
# force quoting even if not necessary.
|
||
if quote or tspecials.search(value):
|
||
return '%s="%s"' % (param, Utils.quote(value))
|
||
else:
|
||
return '%s=%s' % (param, value)
|
||
else:
|
||
return param
|
||
|
||
|
||
|
||
class Message:
|
||
"""Basic message object for use inside the object tree.
|
||
|
||
A message object is defined as something that has a bunch of RFC 2822
|
||
headers and a payload. If the body of the message is a multipart, then
|
||
the payload is a list of Messages, otherwise it is a string.
|
||
|
||
These objects implement part of the `mapping' interface, which assumes
|
||
there is exactly one occurrance of the header per message. Some headers
|
||
do in fact appear multiple times (e.g. Received:) and for those headers,
|
||
you must use the explicit API to set or get all the headers. Not all of
|
||
the mapping methods are implemented.
|
||
|
||
"""
|
||
def __init__(self):
|
||
self._headers = []
|
||
self._unixfrom = None
|
||
self._payload = None
|
||
self._charset = None
|
||
# Defaults for multipart messages
|
||
self.preamble = self.epilogue = None
|
||
|
||
def __str__(self):
|
||
"""Return the entire formatted message as a string.
|
||
This includes the headers, body, and `unixfrom' line.
|
||
"""
|
||
return self.as_string(unixfrom=1)
|
||
|
||
def as_string(self, unixfrom=0):
|
||
"""Return the entire formatted message as a string.
|
||
Optional `unixfrom' when true, means include the Unix From_ envelope
|
||
header.
|
||
"""
|
||
from Generator import Generator
|
||
fp = StringIO()
|
||
g = Generator(fp)
|
||
g(self, unixfrom=unixfrom)
|
||
return fp.getvalue()
|
||
|
||
def is_multipart(self):
|
||
"""Return true if the message consists of multiple parts."""
|
||
if type(self._payload) is ListType:
|
||
return 1
|
||
return 0
|
||
|
||
#
|
||
# Unix From_ line
|
||
#
|
||
def set_unixfrom(self, unixfrom):
|
||
self._unixfrom = unixfrom
|
||
|
||
def get_unixfrom(self):
|
||
return self._unixfrom
|
||
|
||
#
|
||
# Payload manipulation.
|
||
#
|
||
def add_payload(self, payload):
|
||
"""Add the given payload to the current payload.
|
||
|
||
If the current payload is empty, then the current payload will be made
|
||
a scalar, set to the given value.
|
||
"""
|
||
warnings.warn('add_payload() is deprecated, use attach() instead.',
|
||
DeprecationWarning, 2)
|
||
if self._payload is None:
|
||
self._payload = payload
|
||
elif type(self._payload) is ListType:
|
||
self._payload.append(payload)
|
||
elif self.get_main_type() not in (None, 'multipart'):
|
||
raise Errors.MultipartConversionError(
|
||
'Message main Content-Type: must be "multipart" or missing')
|
||
else:
|
||
self._payload = [self._payload, payload]
|
||
|
||
def attach(self, payload):
|
||
"""Add the given payload to the current payload.
|
||
|
||
The current payload will always be a list of objects after this method
|
||
is called. If you want to set the payload to a scalar object
|
||
(e.g. because you're attaching a message/rfc822 subpart), use
|
||
set_payload() instead.
|
||
"""
|
||
if self._payload is None:
|
||
self._payload = [payload]
|
||
else:
|
||
self._payload.append(payload)
|
||
|
||
def get_payload(self, i=None, decode=0):
|
||
"""Return the current payload exactly as is.
|
||
|
||
Optional i returns that index into the payload.
|
||
|
||
Optional decode is a flag indicating whether the payload should be
|
||
decoded or not, according to the Content-Transfer-Encoding: header.
|
||
When true and the message is not a multipart, the payload will be
|
||
decoded if this header's value is `quoted-printable' or `base64'. If
|
||
some other encoding is used, or the header is missing, the payload is
|
||
returned as-is (undecoded). If the message is a multipart and the
|
||
decode flag is true, then None is returned.
|
||
"""
|
||
if i is None:
|
||
payload = self._payload
|
||
elif type(self._payload) is not ListType:
|
||
raise TypeError, i
|
||
else:
|
||
payload = self._payload[i]
|
||
if decode:
|
||
if self.is_multipart():
|
||
return None
|
||
cte = self.get('content-transfer-encoding', '')
|
||
if cte.lower() == 'quoted-printable':
|
||
return Utils._qdecode(payload)
|
||
elif cte.lower() == 'base64':
|
||
return Utils._bdecode(payload)
|
||
# Everything else, including encodings with 8bit or 7bit are returned
|
||
# unchanged.
|
||
return payload
|
||
|
||
|
||
def set_payload(self, payload, charset=None):
|
||
"""Set the payload to the given value.
|
||
|
||
Optionally set the charset, which must be a Charset instance."""
|
||
self._payload = payload
|
||
if charset is not None:
|
||
self.set_charset(charset)
|
||
|
||
def set_charset(self, charset):
|
||
"""Set the charset of the payload to a given character set.
|
||
|
||
charset can be a string or a Charset object. If it is a string, it
|
||
will be converted to a Charset object by calling Charset's
|
||
constructor. If charset is None, the charset parameter will be
|
||
removed from the Content-Type: field. Anything else will generate a
|
||
TypeError.
|
||
|
||
The message will be assumed to be a text message encoded with
|
||
charset.input_charset. It will be converted to charset.output_charset
|
||
and encoded properly, if needed, when generating the plain text
|
||
representation of the message. MIME headers (MIME-Version,
|
||
Content-Type, Content-Transfer-Encoding) will be added as needed.
|
||
"""
|
||
if charset is None:
|
||
self.del_param('charset')
|
||
self._charset = None
|
||
return
|
||
if isinstance(charset, StringType):
|
||
charset = Charset.Charset(charset)
|
||
if not isinstance(charset, Charset.Charset):
|
||
raise TypeError, charset
|
||
# BAW: should we accept strings that can serve as arguments to the
|
||
# Charset constructor?
|
||
self._charset = charset
|
||
if not self.has_key('MIME-Version'):
|
||
self.add_header('MIME-Version', '1.0')
|
||
if not self.has_key('Content-Type'):
|
||
self.add_header('Content-Type', 'text/plain',
|
||
charset=charset.get_output_charset())
|
||
else:
|
||
self.set_param('charset', charset.get_output_charset())
|
||
if not self.has_key('Content-Transfer-Encoding'):
|
||
cte = charset.get_body_encoding()
|
||
if callable(cte):
|
||
cte(self)
|
||
else:
|
||
self.add_header('Content-Transfer-Encoding', cte)
|
||
|
||
def get_charset(self):
|
||
"""Return the Charset object associated with the message's payload."""
|
||
return self._charset
|
||
|
||
#
|
||
# MAPPING INTERFACE (partial)
|
||
#
|
||
def __len__(self):
|
||
"""Return the total number of headers, including duplicates."""
|
||
return len(self._headers)
|
||
|
||
def __getitem__(self, name):
|
||
"""Get a header value.
|
||
|
||
Return None if the header is missing instead of raising an exception.
|
||
|
||
Note that if the header appeared multiple times, exactly which
|
||
occurrance gets returned is undefined. Use getall() to get all
|
||
the values matching a header field name.
|
||
"""
|
||
return self.get(name)
|
||
|
||
def __setitem__(self, name, val):
|
||
"""Set the value of a header.
|
||
|
||
Note: this does not overwrite an existing header with the same field
|
||
name. Use __delitem__() first to delete any existing headers.
|
||
"""
|
||
self._headers.append((name, val))
|
||
|
||
def __delitem__(self, name):
|
||
"""Delete all occurrences of a header, if present.
|
||
|
||
Does not raise an exception if the header is missing.
|
||
"""
|
||
name = name.lower()
|
||
newheaders = []
|
||
for k, v in self._headers:
|
||
if k.lower() <> name:
|
||
newheaders.append((k, v))
|
||
self._headers = newheaders
|
||
|
||
def __contains__(self, key):
|
||
return key.lower() in [k.lower() for k, v in self._headers]
|
||
|
||
def has_key(self, name):
|
||
"""Return true if the message contains the header."""
|
||
missing = []
|
||
return self.get(name, missing) is not missing
|
||
|
||
def keys(self):
|
||
"""Return a list of all the message's header field names.
|
||
|
||
These will be sorted in the order they appeared in the original
|
||
message, and may contain duplicates. Any fields deleted and
|
||
re-inserted are always appended to the header list.
|
||
"""
|
||
return [k for k, v in self._headers]
|
||
|
||
def values(self):
|
||
"""Return a list of all the message's header values.
|
||
|
||
These will be sorted in the order they appeared in the original
|
||
message, and may contain duplicates. Any fields deleted and
|
||
re-inserted are always appended to the header list.
|
||
"""
|
||
return [v for k, v in self._headers]
|
||
|
||
def items(self):
|
||
"""Get all the message's header fields and values.
|
||
|
||
These will be sorted in the order they appeared in the original
|
||
message, and may contain duplicates. Any fields deleted and
|
||
re-inserted are always appended to the header list.
|
||
"""
|
||
return self._headers[:]
|
||
|
||
def get(self, name, failobj=None):
|
||
"""Get a header value.
|
||
|
||
Like __getitem__() but return failobj instead of None when the field
|
||
is missing.
|
||
"""
|
||
name = name.lower()
|
||
for k, v in self._headers:
|
||
if k.lower() == name:
|
||
return v
|
||
return failobj
|
||
|
||
#
|
||
# Additional useful stuff
|
||
#
|
||
|
||
def get_all(self, name, failobj=None):
|
||
"""Return a list of all the values for the named field.
|
||
|
||
These will be sorted in the order they appeared in the original
|
||
message, and may contain duplicates. Any fields deleted and
|
||
re-inserted are always appended to the header list.
|
||
|
||
If no such fields exist, failobj is returned (defaults to None).
|
||
"""
|
||
values = []
|
||
name = name.lower()
|
||
for k, v in self._headers:
|
||
if k.lower() == name:
|
||
values.append(v)
|
||
if not values:
|
||
return failobj
|
||
return values
|
||
|
||
def add_header(self, _name, _value, **_params):
|
||
"""Extended header setting.
|
||
|
||
name is the header field to add. keyword arguments can be used to set
|
||
additional parameters for the header field, with underscores converted
|
||
to dashes. Normally the parameter will be added as key="value" unless
|
||
value is None, in which case only the key will be added.
|
||
|
||
Example:
|
||
|
||
msg.add_header('content-disposition', 'attachment', filename='bud.gif')
|
||
|
||
"""
|
||
parts = []
|
||
for k, v in _params.items():
|
||
if v is None:
|
||
parts.append(k.replace('_', '-'))
|
||
else:
|
||
parts.append(_formatparam(k.replace('_', '-'), v))
|
||
if _value is not None:
|
||
parts.insert(0, _value)
|
||
self._headers.append((_name, SEMISPACE.join(parts)))
|
||
|
||
def get_type(self, failobj=None):
|
||
"""Returns the message's content type.
|
||
|
||
The returned string is coerced to lowercase and returned as a single
|
||
string of the form `maintype/subtype'. If there was no Content-Type:
|
||
header in the message, failobj is returned (defaults to None).
|
||
"""
|
||
missing = []
|
||
value = self.get('content-type', missing)
|
||
if value is missing:
|
||
return failobj
|
||
return paramre.split(value)[0].lower()
|
||
|
||
def get_main_type(self, failobj=None):
|
||
"""Return the message's main content type if present."""
|
||
missing = []
|
||
ctype = self.get_type(missing)
|
||
if ctype is missing:
|
||
return failobj
|
||
parts = ctype.split('/')
|
||
if len(parts) > 0:
|
||
return ctype.split('/')[0]
|
||
return failobj
|
||
|
||
def get_subtype(self, failobj=None):
|
||
"""Return the message's content subtype if present."""
|
||
missing = []
|
||
ctype = self.get_type(missing)
|
||
if ctype is missing:
|
||
return failobj
|
||
parts = ctype.split('/')
|
||
if len(parts) > 1:
|
||
return ctype.split('/')[1]
|
||
return failobj
|
||
|
||
def _get_params_preserve(self, failobj, header):
|
||
# Like get_params() but preserves the quoting of values. BAW:
|
||
# should this be part of the public interface?
|
||
missing = []
|
||
value = self.get(header, missing)
|
||
if value is missing:
|
||
return failobj
|
||
params = []
|
||
for p in paramre.split(value):
|
||
try:
|
||
name, val = p.split('=', 1)
|
||
name = name.rstrip()
|
||
val = val.lstrip()
|
||
except ValueError:
|
||
# Must have been a bare attribute
|
||
name = p
|
||
val = ''
|
||
params.append((name, val))
|
||
return params
|
||
|
||
def get_params(self, failobj=None, header='content-type', unquote=1):
|
||
"""Return the message's Content-Type: parameters, as a list.
|
||
|
||
The elements of the returned list are 2-tuples of key/value pairs, as
|
||
split on the `=' sign. The left hand side of the `=' is the key,
|
||
while the right hand side is the value. If there is no `=' sign in
|
||
the parameter the value is the empty string. The value is always
|
||
unquoted, unless unquote is set to a false value.
|
||
|
||
Optional failobj is the object to return if there is no Content-Type:
|
||
header. Optional header is the header to search instead of
|
||
Content-Type:.
|
||
"""
|
||
missing = []
|
||
params = self._get_params_preserve(missing, header)
|
||
if params is missing:
|
||
return failobj
|
||
if unquote:
|
||
return [(k, Utils.unquote(v)) for k, v in params]
|
||
else:
|
||
return params
|
||
|
||
def get_param(self, param, failobj=None, header='content-type', unquote=1):
|
||
"""Return the parameter value if found in the Content-Type: header.
|
||
|
||
Optional failobj is the object to return if there is no Content-Type:
|
||
header. Optional header is the header to search instead of
|
||
Content-Type:
|
||
|
||
Parameter keys are always compared case insensitively. Values are
|
||
always unquoted, unless unquote is set to a false value.
|
||
"""
|
||
if not self.has_key(header):
|
||
return failobj
|
||
for k, v in self._get_params_preserve(failobj, header):
|
||
if k.lower() == param.lower():
|
||
if unquote:
|
||
return Utils.unquote(v)
|
||
else:
|
||
return v
|
||
return failobj
|
||
|
||
def set_param(self, param, value, header='Content-Type', requote=1):
|
||
"""Set a parameter in the Content-Type: header.
|
||
|
||
If the parameter already exists in the header, its value will be
|
||
replaced with the new value.
|
||
|
||
If header is Content-Type: and has not yet been defined in this
|
||
message, it will be set to "text/plain" and the new parameter and
|
||
value will be appended, as per RFC 2045.
|
||
|
||
An alternate header can specified in the header argument, and
|
||
all parameters will be quoted as appropriate unless requote is
|
||
set to a false value.
|
||
"""
|
||
if not self.has_key(header) and header.lower() == 'content-type':
|
||
ctype = 'text/plain'
|
||
else:
|
||
ctype = self.get(header)
|
||
if not self.get_param(param, header=header):
|
||
if not ctype:
|
||
ctype = _formatparam(param, value, requote)
|
||
else:
|
||
ctype = SEMISPACE.join(
|
||
[ctype, _formatparam(param, value, requote)])
|
||
else:
|
||
ctype = ''
|
||
for old_param, old_value in self.get_params(header=header,
|
||
unquote=requote):
|
||
append_param = ''
|
||
if old_param.lower() == param.lower():
|
||
append_param = _formatparam(param, value, requote)
|
||
else:
|
||
append_param = _formatparam(old_param, old_value, requote)
|
||
if not ctype:
|
||
ctype = append_param
|
||
else:
|
||
ctype = SEMISPACE.join([ctype, append_param])
|
||
if ctype <> self.get(header):
|
||
del self[header]
|
||
self[header] = ctype
|
||
|
||
def del_param(self, param, header='content-type', requote=1):
|
||
"""Remove the given parameter completely from the Content-Type header.
|
||
|
||
The header will be re-written in place without param or its value.
|
||
All values will be quoted as appropriate unless requote is set to a
|
||
false value.
|
||
"""
|
||
if not self.has_key(header):
|
||
return
|
||
new_ctype = ''
|
||
for p, v in self.get_params(header, unquote=requote):
|
||
if p.lower() <> param.lower():
|
||
if not new_ctype:
|
||
new_ctype = _formatparam(p, v, requote)
|
||
else:
|
||
new_ctype = SEMISPACE.join([new_ctype,
|
||
_formatparam(p, v, requote)])
|
||
if new_ctype <> self.get(header):
|
||
del self[header]
|
||
self[header] = new_ctype
|
||
|
||
def set_type(self, type, header='Content-Type', requote=1):
|
||
"""Set the main type and subtype for the Content-Type: header.
|
||
|
||
type must be a string in the form "maintype/subtype", otherwise a
|
||
ValueError is raised.
|
||
|
||
This method replaces the Content-Type: header, keeping all the
|
||
parameters in place. If requote is false, this leaves the existing
|
||
header's quoting as is. Otherwise, the parameters will be quoted (the
|
||
default).
|
||
|
||
An alternate header can be specified in the header argument. When the
|
||
Content-Type: header is set, we'll always also add a MIME-Version:
|
||
header.
|
||
"""
|
||
# BAW: should we be strict?
|
||
if not type.count('/') == 1:
|
||
raise ValueError
|
||
# Set the Content-Type: you get a MIME-Version:
|
||
if header.lower() == 'content-type':
|
||
del self['mime-version']
|
||
self['MIME-Version'] = '1.0'
|
||
if not self.has_key(header):
|
||
self[header] = type
|
||
return
|
||
params = self.get_params(header, unquote=requote)
|
||
del self[header]
|
||
self[header] = type
|
||
# Skip the first param; it's the old type.
|
||
for p, v in params[1:]:
|
||
self.set_param(p, v, header, requote)
|
||
|
||
def get_filename(self, failobj=None):
|
||
"""Return the filename associated with the payload if present.
|
||
|
||
The filename is extracted from the Content-Disposition: header's
|
||
`filename' parameter, and it is unquoted.
|
||
"""
|
||
missing = []
|
||
filename = self.get_param('filename', missing, 'content-disposition')
|
||
if filename is missing:
|
||
return failobj
|
||
return Utils.unquote(filename.strip())
|
||
|
||
def get_boundary(self, failobj=None):
|
||
"""Return the boundary associated with the payload if present.
|
||
|
||
The boundary is extracted from the Content-Type: header's `boundary'
|
||
parameter, and it is unquoted.
|
||
"""
|
||
missing = []
|
||
boundary = self.get_param('boundary', missing)
|
||
if boundary is missing:
|
||
return failobj
|
||
return Utils.unquote(boundary.strip())
|
||
|
||
def set_boundary(self, boundary):
|
||
"""Set the boundary parameter in Content-Type: to 'boundary'.
|
||
|
||
This is subtly different than deleting the Content-Type: header and
|
||
adding a new one with a new boundary parameter via add_header(). The
|
||
main difference is that using the set_boundary() method preserves the
|
||
order of the Content-Type: header in the original message.
|
||
|
||
HeaderParseError is raised if the message has no Content-Type: header.
|
||
"""
|
||
missing = []
|
||
params = self._get_params_preserve(missing, 'content-type')
|
||
if params is missing:
|
||
# There was no Content-Type: header, and we don't know what type
|
||
# to set it to, so raise an exception.
|
||
raise Errors.HeaderParseError, 'No Content-Type: header found'
|
||
newparams = []
|
||
foundp = 0
|
||
for pk, pv in params:
|
||
if pk.lower() == 'boundary':
|
||
newparams.append(('boundary', '"%s"' % boundary))
|
||
foundp = 1
|
||
else:
|
||
newparams.append((pk, pv))
|
||
if not foundp:
|
||
# The original Content-Type: header had no boundary attribute.
|
||
# Tack one one the end. BAW: should we raise an exception
|
||
# instead???
|
||
newparams.append(('boundary', '"%s"' % boundary))
|
||
# Replace the existing Content-Type: header with the new value
|
||
newheaders = []
|
||
for h, v in self._headers:
|
||
if h.lower() == 'content-type':
|
||
parts = []
|
||
for k, v in newparams:
|
||
if v == '':
|
||
parts.append(k)
|
||
else:
|
||
parts.append('%s=%s' % (k, v))
|
||
newheaders.append((h, SEMISPACE.join(parts)))
|
||
|
||
else:
|
||
newheaders.append((h, v))
|
||
self._headers = newheaders
|
||
|
||
def walk(self):
|
||
"""Walk over the message tree, yielding each subpart.
|
||
|
||
The walk is performed in depth-first order. This method is a
|
||
generator.
|
||
"""
|
||
yield self
|
||
if self.is_multipart():
|
||
for subpart in self.get_payload():
|
||
for subsubpart in subpart.walk():
|
||
yield subsubpart
|
||
|
||
def get_charsets(self, failobj=None):
|
||
"""Return a list containing the charset(s) used in this message.
|
||
|
||
The returned list of items describes the Content-Type: headers'
|
||
charset parameter for this message and all the subparts in its
|
||
payload.
|
||
|
||
Each item will either be a string (the value of the charset parameter
|
||
in the Content-Type: header of that part) or the value of the
|
||
'failobj' parameter (defaults to None), if the part does not have a
|
||
main MIME type of "text", or the charset is not defined.
|
||
|
||
The list will contain one string for each part of the message, plus
|
||
one for the container message (i.e. self), so that a non-multipart
|
||
message will still return a list of length 1.
|
||
"""
|
||
return [part.get_param('charset', failobj) for part in self.walk()]
|