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"""
The Request class is used as a wrapper around the standard request object.
The wrapped request then offers a richer API, in particular :
- content automatically parsed according to `Content-Type` header,
and available as `request.data`
- full support of PUT method, including support for file uploads
- form overloading of HTTP method, content type and content
"""
from __future__ import unicode_literals
import sys
from django.conf import settings
from django.http import QueryDict
from django.http.multipartparser import parse_header
from django.http.request import RawPostDataException
from django.utils import six
from django.utils.datastructures import MultiValueDict
from rest_framework import HTTP_HEADER_ENCODING, exceptions
from rest_framework.settings import api_settings
def is_form_media_type(media_type):
"""
Return True if the media type is a valid form media type.
"""
base_media_type, params = parse_header(media_type.encode(HTTP_HEADER_ENCODING))
return (base_media_type == 'application/x-www-form-urlencoded' or
base_media_type == 'multipart/form-data')
class override_method(object):
"""
A context manager that temporarily overrides the method on a request,
additionally setting the `view.request` attribute.
Usage:
with override_method(view, request, 'POST') as request:
... # Do stuff with `view` and `request`
"""
def __init__(self, view, request, method):
self.view = view
self.request = request
self.method = method
self.action = getattr(view, 'action', None)
def __enter__(self):
self.view.request = clone_request(self.request, self.method)
# For viewsets we also set the `.action` attribute.
action_map = getattr(self.view, 'action_map', {})
self.view.action = action_map.get(self.method.lower())
return self.view.request
def __exit__(self, *args, **kwarg):
self.view.request = self.request
self.view.action = self.action
class Empty(object):
"""
Placeholder for unset attributes.
Cannot use `None`, as that may be a valid value.
"""
pass
def _hasattr(obj, name):
return not getattr(obj, name) is Empty
def clone_request(request, method):
"""
Internal helper method to clone a request, replacing with a different
HTTP method. Used for checking permissions against other methods.
"""
ret = Request(request=request._request,
parsers=request.parsers,
authenticators=request.authenticators,
negotiator=request.negotiator,
parser_context=request.parser_context)
ret._data = request._data
ret._files = request._files
ret._full_data = request._full_data
ret._content_type = request._content_type
ret._stream = request._stream
ret.method = method
if hasattr(request, '_user'):
ret._user = request._user
if hasattr(request, '_auth'):
ret._auth = request._auth
if hasattr(request, '_authenticator'):
ret._authenticator = request._authenticator
if hasattr(request, 'accepted_renderer'):
ret.accepted_renderer = request.accepted_renderer
if hasattr(request, 'accepted_media_type'):
ret.accepted_media_type = request.accepted_media_type
if hasattr(request, 'version'):
ret.version = request.version
if hasattr(request, 'versioning_scheme'):
ret.versioning_scheme = request.versioning_scheme
return ret
class ForcedAuthentication(object):
"""
This authentication class is used if the test client or request factory
forcibly authenticated the request.
"""
def __init__(self, force_user, force_token):
self.force_user = force_user
self.force_token = force_token
def authenticate(self, request):
return (self.force_user, self.force_token)
class Request(object):
"""
Wrapper allowing to enhance a standard `HttpRequest` instance.
Kwargs:
- request(HttpRequest). The original request instance.
- parsers_classes(list/tuple). The parsers to use for parsing the
request content.
- authentication_classes(list/tuple). The authentications used to try
authenticating the request's user.
"""
def __init__(self, request, parsers=None, authenticators=None,
negotiator=None, parser_context=None):
self._request = request
self.parsers = parsers or ()
self.authenticators = authenticators or ()
self.negotiator = negotiator or self._default_negotiator()
self.parser_context = parser_context
self._data = Empty
self._files = Empty
self._full_data = Empty
self._content_type = Empty
self._stream = Empty
if self.parser_context is None:
self.parser_context = {}
self.parser_context['request'] = self
self.parser_context['encoding'] = request.encoding or settings.DEFAULT_CHARSET
force_user = getattr(request, '_force_auth_user', None)
force_token = getattr(request, '_force_auth_token', None)
if force_user is not None or force_token is not None:
forced_auth = ForcedAuthentication(force_user, force_token)
self.authenticators = (forced_auth,)
def _default_negotiator(self):
return api_settings.DEFAULT_CONTENT_NEGOTIATION_CLASS()
@property
def content_type(self):
meta = self._request.META
return meta.get('CONTENT_TYPE', meta.get('HTTP_CONTENT_TYPE', ''))
@property
def stream(self):
"""
Returns an object that may be used to stream the request content.
"""
if not _hasattr(self, '_stream'):
self._load_stream()
return self._stream
@property
def query_params(self):
"""
More semantically correct name for request.GET.
"""
return self._request.GET
@property
def data(self):
if not _hasattr(self, '_full_data'):
self._load_data_and_files()
return self._full_data
@property
def user(self):
"""
Returns the user associated with the current request, as authenticated
by the authentication classes provided to the request.
"""
if not hasattr(self, '_user'):
self._authenticate()
return self._user
@user.setter
def user(self, value):
"""
Sets the user on the current request. This is necessary to maintain
compatibility with django.contrib.auth where the user property is
set in the login and logout functions.
Note that we also set the user on Django's underlying `HttpRequest`
instance, ensuring that it is available to any middleware in the stack.
"""
self._user = value
self._request.user = value
@property
def auth(self):
"""
Returns any non-user authentication information associated with the
request, such as an authentication token.
"""
if not hasattr(self, '_auth'):
self._authenticate()
return self._auth
@auth.setter
def auth(self, value):
"""
Sets any non-user authentication information associated with the
request, such as an authentication token.
"""
self._auth = value
self._request.auth = value
@property
def successful_authenticator(self):
"""
Return the instance of the authentication instance class that was used
to authenticate the request, or `None`.
"""
if not hasattr(self, '_authenticator'):
self._authenticate()
return self._authenticator
def _load_data_and_files(self):
"""
Parses the request content into `self.data`.
"""
if not _hasattr(self, '_data'):
self._data, self._files = self._parse()
if self._files:
self._full_data = self._data.copy()
self._full_data.update(self._files)
else:
self._full_data = self._data
def _load_stream(self):
"""
Return the content body of the request, as a stream.
"""
meta = self._request.META
try:
content_length = int(
meta.get('CONTENT_LENGTH', meta.get('HTTP_CONTENT_LENGTH', 0))
)
except (ValueError, TypeError):
content_length = 0
if content_length == 0:
self._stream = None
elif not self._request._read_started:
self._stream = self._request
else:
self._stream = six.BytesIO(self.body)
def _supports_form_parsing(self):
"""
Return True if this requests supports parsing form data.
"""
form_media = (
'application/x-www-form-urlencoded',
'multipart/form-data'
)
return any([parser.media_type in form_media for parser in self.parsers])
def _parse(self):
"""
Parse the request content, returning a two-tuple of (data, files)
May raise an `UnsupportedMediaType`, or `ParseError` exception.
"""
media_type = self.content_type
try:
stream = self.stream
except RawPostDataException:
if not hasattr(self._request, '_post'):
raise
# If request.POST has been accessed in middleware, and a method='POST'
# request was made with 'multipart/form-data', then the request stream
# will already have been exhausted.
if self._supports_form_parsing():
return (self._request.POST, self._request.FILES)
stream = None
if stream is None or media_type is None:
if media_type and not is_form_media_type(media_type):
empty_data = QueryDict('', encoding=self._request._encoding)
else:
empty_data = {}
empty_files = MultiValueDict()
return (empty_data, empty_files)
parser = self.negotiator.select_parser(self, self.parsers)
if not parser:
raise exceptions.UnsupportedMediaType(media_type)
try:
parsed = parser.parse(stream, media_type, self.parser_context)
except:
# If we get an exception during parsing, fill in empty data and
# re-raise. Ensures we don't simply repeat the error when
# attempting to render the browsable renderer response, or when
# logging the request or similar.
self._data = QueryDict('', encoding=self._request._encoding)
self._files = MultiValueDict()
self._full_data = self._data
raise
# Parser classes may return the raw data, or a
# DataAndFiles object. Unpack the result as required.
try:
return (parsed.data, parsed.files)
except AttributeError:
empty_files = MultiValueDict()
return (parsed, empty_files)
def _authenticate(self):
"""
Attempt to authenticate the request using each authentication instance
in turn.
Returns a three-tuple of (authenticator, user, authtoken).
"""
for authenticator in self.authenticators:
try:
user_auth_tuple = authenticator.authenticate(self)
except exceptions.APIException:
self._not_authenticated()
raise
if user_auth_tuple is not None:
self._authenticator = authenticator
self.user, self.auth = user_auth_tuple
return
self._not_authenticated()
def _not_authenticated(self):
"""
Return a three-tuple of (authenticator, user, authtoken), representing
an unauthenticated request.
By default this will be (None, AnonymousUser, None).
"""
self._authenticator = None
if api_settings.UNAUTHENTICATED_USER:
self.user = api_settings.UNAUTHENTICATED_USER()
else:
self.user = None
if api_settings.UNAUTHENTICATED_TOKEN:
self.auth = api_settings.UNAUTHENTICATED_TOKEN()
else:
self.auth = None
def __getattribute__(self, attr):
"""
If an attribute does not exist on this instance, then we also attempt
to proxy it to the underlying HttpRequest object.
"""
try:
return super(Request, self).__getattribute__(attr)
except AttributeError:
info = sys.exc_info()
try:
return getattr(self._request, attr)
except AttributeError:
six.reraise(info[0], info[1], info[2].tb_next)
@property
def DATA(self):
raise NotImplementedError(
'`request.DATA` has been deprecated in favor of `request.data` '
'since version 3.0, and has been fully removed as of version 3.2.'
)
@property
def POST(self):
# Ensure that request.POST uses our request parsing.
if not _hasattr(self, '_data'):
self._load_data_and_files()
if is_form_media_type(self.content_type):
return self._data
return QueryDict('', encoding=self._request._encoding)
@property
def FILES(self):
# Leave this one alone for backwards compat with Django's request.FILES
# Different from the other two cases, which are not valid property
# names on the WSGIRequest class.
if not _hasattr(self, '_files'):
self._load_data_and_files()
return self._files
@property
def QUERY_PARAMS(self):
raise NotImplementedError(
'`request.QUERY_PARAMS` has been deprecated in favor of `request.query_params` '
'since version 3.0, and has been fully removed as of version 3.2.'
)
def force_plaintext_errors(self, value):
# Hack to allow our exception handler to force choice of
# plaintext or html error responses.
self._request.is_ajax = lambda: value