diff options
Diffstat (limited to 'djangorestframework/request.py')
| -rw-r--r-- | djangorestframework/request.py | 205 |
1 files changed, 205 insertions, 0 deletions
diff --git a/djangorestframework/request.py b/djangorestframework/request.py new file mode 100644 index 00000000..d4ea1e01 --- /dev/null +++ b/djangorestframework/request.py @@ -0,0 +1,205 @@ +""" +The :mod:`request` module provides a :class:`Request` class used to wrap the standard `request` +object received in all the views. + +The wrapped request then offers a richer API, in particular : + + - content automatically parsed according to `Content-Type` header, and available as :meth:`.DATA<Request.DATA>` + - full support of PUT method, including support for file uploads + - form overloading of HTTP method, content type and content +""" + +from django.http import HttpRequest + +from djangorestframework.response import ImmediateResponse +from djangorestframework import status +from djangorestframework.utils.mediatypes import is_form_media_type, order_by_precedence +from djangorestframework.utils import as_tuple + +from StringIO import StringIO + + +__all__ = ('Request',) + + +class Request(object): + """ + 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. + """ + + _USE_FORM_OVERLOADING = True + _METHOD_PARAM = '_method' + _CONTENTTYPE_PARAM = '_content_type' + _CONTENT_PARAM = '_content' + + def __init__(self, request=None, parsers=None): + self.request = request + if parsers is not None: + self.parsers = parsers + + @property + def method(self): + """ + Returns the HTTP method. + + This allows the `method` to be overridden by using a hidden `form` field + on a form POST request. + """ + if not hasattr(self, '_method'): + self._load_method_and_content_type() + return self._method + + @property + def content_type(self): + """ + Returns the content type header. + + This should be used instead of ``request.META.get('HTTP_CONTENT_TYPE')``, + as it allows the content type to be overridden by using a hidden form + field on a form POST request. + """ + if not hasattr(self, '_content_type'): + self._load_method_and_content_type() + return self._content_type + + @property + def DATA(self): + """ + Parses the request body and returns the data. + + Similar to ``request.POST``, except that it handles arbitrary parsers, + and also works on methods other than POST (eg PUT). + """ + if not hasattr(self, '_data'): + self._load_data_and_files() + return self._data + + @property + def FILES(self): + """ + Parses the request body and returns the files. + Similar to ``request.FILES``, except that it handles arbitrary parsers, + and also works on methods other than POST (eg PUT). + """ + if not hasattr(self, '_files'): + self._load_data_and_files() + return self._files + + def _load_data_and_files(self): + """ + Parses the request content into self.DATA and self.FILES. + """ + if not hasattr(self, '_content_type'): + self._load_method_and_content_type() + + if not hasattr(self, '_data'): + (self._data, self._files) = self._parse(self._get_stream(), self._content_type) + + def _load_method_and_content_type(self): + """ + Sets the method and content_type, and then check if they've been overridden. + """ + self._content_type = self.META.get('HTTP_CONTENT_TYPE', self.META.get('CONTENT_TYPE', '')) + self._perform_form_overloading() + # if the HTTP method was not overloaded, we take the raw HTTP method + if not hasattr(self, '_method'): + self._method = self.request.method + + def _get_stream(self): + """ + Returns an object that may be used to stream the request content. + """ + + try: + content_length = int(self.META.get('CONTENT_LENGTH', self.META.get('HTTP_CONTENT_LENGTH'))) + except (ValueError, TypeError): + content_length = 0 + + # TODO: Add 1.3's LimitedStream to compat and use that. + # NOTE: Currently only supports parsing request body as a stream with 1.3 + if content_length == 0: + return None + elif hasattr(self, 'read'): + return self + return StringIO(self.raw_post_data) + + def _perform_form_overloading(self): + """ + If this is a form POST request, then we need to check if the method and content/content_type have been + overridden by setting them in hidden form fields or not. + """ + + # We only need to use form overloading on form POST requests. + if (not self._USE_FORM_OVERLOADING or self.request.method != 'POST' + or not is_form_media_type(self._content_type)): + return + + # At this point we're committed to parsing the request as form data. + self._data = data = self.POST.copy() + self._files = self.FILES + + # Method overloading - change the method and remove the param from the content. + if self._METHOD_PARAM in data: + # NOTE: unlike `get`, `pop` on a `QueryDict` seems to return a list of values. + self._method = self._data.pop(self._METHOD_PARAM)[0].upper() + + # Content overloading - modify the content type, and re-parse. + if self._CONTENT_PARAM in data and self._CONTENTTYPE_PARAM in data: + self._content_type = self._data.pop(self._CONTENTTYPE_PARAM)[0] + stream = StringIO(self._data.pop(self._CONTENT_PARAM)[0]) + (self._data, self._files) = self._parse(stream, self._content_type) + + def _parse(self, stream, content_type): + """ + Parse the request content. + + May raise a 415 ImmediateResponse (Unsupported Media Type), or a 400 ImmediateResponse (Bad Request). + """ + if stream is None or content_type is None: + return (None, None) + + for parser in as_tuple(self.parsers): + if parser.can_handle_request(content_type): + return parser.parse(stream) + + raise ImmediateResponse({ + 'error': 'Unsupported media type in request \'%s\'.' % content_type}, + status=status.HTTP_415_UNSUPPORTED_MEDIA_TYPE) + + @property + def _parsed_media_types(self): + """ + Return a list of all the media types that this view can parse. + """ + return [parser.media_type for parser in self.parsers] + + @property + def _default_parser(self): + """ + Return the view's default parser class. + """ + return self.parsers[0] + + def _get_parsers(self): + if hasattr(self, '_parsers'): + return self._parsers + return () + + def _set_parsers(self, value): + self._parsers = value + + parsers = property(_get_parsers, _set_parsers) + + def __getattr__(self, name): + """ + When an attribute is not present on the calling instance, try to get it + from the original request. + """ + if hasattr(self.request, name): + return getattr(self.request, name) + else: + return super(Request, self).__getattribute__(name) |