""" 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 """ import io import sys from contextlib import contextmanager from django.conf import settings from django.http import HttpRequest, QueryDict from django.http.request import RawPostDataException from django.utils.datastructures import MultiValueDict from django.utils.http import parse_header_parameters from rest_framework import 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_parameters(media_type) return (base_media_type == 'application/x-www-form-urlencoded' or base_media_type == 'multipart/form-data') class override_method: """ 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 WrappedAttributeError(Exception): pass @contextmanager def wrap_attributeerrors(): """ Used to re-raise AttributeErrors caught during authentication, preventing these errors from otherwise being handled by the attribute access protocol. """ try: yield except AttributeError: info = sys.exc_info() exc = WrappedAttributeError(str(info[1])) raise exc.with_traceback(info[2]) class Empty: """ 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: """ 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: """ Wrapper allowing to enhance a standard `HttpRequest` instance. Kwargs: - request(HttpRequest). The original request instance. - parsers(list/tuple). The parsers to use for parsing the request content. - authenticators(list/tuple). The authenticators used to try authenticating the request's user. """ def __init__(self, request, parsers=None, authenticators=None, negotiator=None, parser_context=None): assert isinstance(request, HttpRequest), ( 'The `request` argument must be an instance of ' '`django.http.HttpRequest`, not `{}.{}`.' .format(request.__class__.__module__, request.__class__.__name__) ) 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 __repr__(self): return '<%s.%s: %s %r>' % ( self.__class__.__module__, self.__class__.__name__, self.method, self.get_full_path()) # Allow generic typing checking for requests. def __class_getitem__(cls, *args, **kwargs): return cls 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'): with wrap_attributeerrors(): 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'): with wrap_attributeerrors(): 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'): with wrap_attributeerrors(): 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'): with wrap_attributeerrors(): 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 # if a form media type, copy data & files refs to the underlying # http request so that closable objects are handled appropriately. if is_form_media_type(self.content_type): self._request._post = self.POST self._request._files = self.FILES 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 = io.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 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 Exception: # 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. """ 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): """ Set authenticator, user & authtoken representing an unauthenticated request. Defaults are 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 __getattr__(self, attr): """ If an attribute does not exist on this instance, then we also attempt to proxy it to the underlying HttpRequest object. """ try: _request = self.__getattribute__("_request") return getattr(_request, attr) except AttributeError: raise AttributeError(f"'{self.__class__.__name__}' object has no attribute '{attr}'") @property def POST(self): # Ensure that request.POST uses our request parsing. if not _hasattr(self, '_data'): with wrap_attributeerrors(): 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'): with wrap_attributeerrors(): self._load_data_and_files() return self._files 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