956 lines
34 KiB
Plaintext
956 lines
34 KiB
Plaintext
============================
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Request and response objects
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============================
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.. module:: django.http
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:synopsis: Classes dealing with HTTP requests and responses.
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Quick overview
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==============
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Django uses request and response objects to pass state through the system.
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When a page is requested, Django creates an :class:`HttpRequest` object that
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contains metadata about the request. Then Django loads the appropriate view,
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passing the :class:`HttpRequest` as the first argument to the view function.
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Each view is responsible for returning an :class:`HttpResponse` object.
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This document explains the APIs for :class:`HttpRequest` and
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:class:`HttpResponse` objects, which are defined in the :mod:`django.http`
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module.
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HttpRequest objects
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===================
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.. class:: HttpRequest
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.. _httprequest-attributes:
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Attributes
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----------
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All attributes should be considered read-only, unless stated otherwise below.
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``session`` is a notable exception.
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.. attribute:: HttpRequest.scheme
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.. versionadded:: 1.7
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A string representing the scheme of the request (``http`` or ``https``
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usually).
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.. attribute:: HttpRequest.body
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The raw HTTP request body as a byte string. This is useful for processing
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data in different ways than conventional HTML forms: binary images,
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XML payload etc. For processing conventional form data, use ``HttpRequest.POST``.
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You can also read from an HttpRequest using a file-like interface. See
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:meth:`HttpRequest.read()`.
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.. attribute:: HttpRequest.path
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A string representing the full path to the requested page, not including
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the domain.
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Example: ``"/music/bands/the_beatles/"``
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.. attribute:: HttpRequest.path_info
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Under some Web server configurations, the portion of the URL after the
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host name is split up into a script prefix portion and a path info
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portion. The ``path_info`` attribute always contains the path info portion
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of the path, no matter what Web server is being used. Using this instead
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of :attr:`~HttpRequest.path` can make your code easier to move between
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test and deployment servers.
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For example, if the ``WSGIScriptAlias`` for your application is set to
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``"/minfo"``, then ``path`` might be ``"/minfo/music/bands/the_beatles/"``
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and ``path_info`` would be ``"/music/bands/the_beatles/"``.
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.. attribute:: HttpRequest.method
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A string representing the HTTP method used in the request. This is
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guaranteed to be uppercase. Example::
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if request.method == 'GET':
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do_something()
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elif request.method == 'POST':
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do_something_else()
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.. attribute:: HttpRequest.encoding
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A string representing the current encoding used to decode form submission
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data (or ``None``, which means the :setting:`DEFAULT_CHARSET` setting is
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used). You can write to this attribute to change the encoding used when
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accessing the form data. Any subsequent attribute accesses (such as reading
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from ``GET`` or ``POST``) will use the new ``encoding`` value. Useful if
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you know the form data is not in the :setting:`DEFAULT_CHARSET` encoding.
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.. attribute:: HttpRequest.GET
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A dictionary-like object containing all given HTTP GET parameters. See the
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:class:`QueryDict` documentation below.
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.. attribute:: HttpRequest.POST
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A dictionary-like object containing all given HTTP POST parameters,
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providing that the request contains form data. See the
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:class:`QueryDict` documentation below. If you need to access raw or
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non-form data posted in the request, access this through the
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:attr:`HttpRequest.body` attribute instead.
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It's possible that a request can come in via POST with an empty ``POST``
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dictionary -- if, say, a form is requested via the POST HTTP method but
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does not include form data. Therefore, you shouldn't use ``if request.POST``
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to check for use of the POST method; instead, use ``if request.method ==
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"POST"`` (see above).
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Note: ``POST`` does *not* include file-upload information. See ``FILES``.
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.. attribute:: HttpRequest.REQUEST
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.. deprecated:: 1.7
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Use the more explicit ``GET`` and ``POST`` instead.
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For convenience, a dictionary-like object that searches ``POST`` first,
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then ``GET``. Inspired by PHP's ``$_REQUEST``.
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For example, if ``GET = {"name": "john"}`` and ``POST = {"age": '34'}``,
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``REQUEST["name"]`` would be ``"john"``, and ``REQUEST["age"]`` would be
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``"34"``.
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It's strongly suggested that you use ``GET`` and ``POST`` instead of
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``REQUEST``, because the former are more explicit.
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.. attribute:: HttpRequest.COOKIES
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A standard Python dictionary containing all cookies. Keys and values are
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strings.
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.. attribute:: HttpRequest.FILES
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A dictionary-like object containing all uploaded files. Each key in
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``FILES`` is the ``name`` from the ``<input type="file" name="" />``. Each
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value in ``FILES`` is an :class:`UploadedFile` as described below.
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See :doc:`/topics/files` for more information.
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Note that ``FILES`` will only contain data if the request method was POST
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and the ``<form>`` that posted to the request had
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``enctype="multipart/form-data"``. Otherwise, ``FILES`` will be a blank
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dictionary-like object.
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.. attribute:: HttpRequest.META
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A standard Python dictionary containing all available HTTP headers.
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Available headers depend on the client and server, but here are some
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examples:
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* ``CONTENT_LENGTH`` -- the length of the request body (as a string).
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* ``CONTENT_TYPE`` -- the MIME type of the request body.
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* ``HTTP_ACCEPT_ENCODING`` -- Acceptable encodings for the response.
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* ``HTTP_ACCEPT_LANGUAGE`` -- Acceptable languages for the response.
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* ``HTTP_HOST`` -- The HTTP Host header sent by the client.
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* ``HTTP_REFERER`` -- The referring page, if any.
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* ``HTTP_USER_AGENT`` -- The client's user-agent string.
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* ``QUERY_STRING`` -- The query string, as a single (unparsed) string.
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* ``REMOTE_ADDR`` -- The IP address of the client.
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* ``REMOTE_HOST`` -- The hostname of the client.
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* ``REMOTE_USER`` -- The user authenticated by the Web server, if any.
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* ``REQUEST_METHOD`` -- A string such as ``"GET"`` or ``"POST"``.
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* ``SERVER_NAME`` -- The hostname of the server.
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* ``SERVER_PORT`` -- The port of the server (as a string).
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With the exception of ``CONTENT_LENGTH`` and ``CONTENT_TYPE``, as given
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above, any HTTP headers in the request are converted to ``META`` keys by
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converting all characters to uppercase, replacing any hyphens with
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underscores and adding an ``HTTP_`` prefix to the name. So, for example, a
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header called ``X-Bender`` would be mapped to the ``META`` key
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``HTTP_X_BENDER``.
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.. attribute:: HttpRequest.user
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An object of type :setting:`AUTH_USER_MODEL` representing the currently
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logged-in user. If the user isn't currently logged in, ``user`` will be set
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to an instance of :class:`django.contrib.auth.models.AnonymousUser`. You
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can tell them apart with
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:meth:`~django.contrib.auth.models.User.is_authenticated`, like so::
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if request.user.is_authenticated():
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# Do something for logged-in users.
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else:
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# Do something for anonymous users.
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``user`` is only available if your Django installation has the
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:class:`~django.contrib.auth.middleware.AuthenticationMiddleware`
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activated. For more, see :doc:`/topics/auth/index`.
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.. attribute:: HttpRequest.session
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A readable-and-writable, dictionary-like object that represents the current
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session. This is only available if your Django installation has session
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support activated. See the :doc:`session documentation
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</topics/http/sessions>` for full details.
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.. attribute:: HttpRequest.urlconf
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Not defined by Django itself, but will be read if other code (e.g., a custom
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middleware class) sets it. When present, this will be used as the root
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URLconf for the current request, overriding the :setting:`ROOT_URLCONF`
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setting. See :ref:`how-django-processes-a-request` for details.
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.. attribute:: HttpRequest.resolver_match
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An instance of :class:`~django.core.urlresolvers.ResolverMatch` representing
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the resolved url. This attribute is only set after url resolving took place,
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which means it's available in all views but not in middleware methods which
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are executed before url resolving takes place (like ``process_request``, you
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can use ``process_view`` instead).
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Methods
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-------
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.. method:: HttpRequest.get_host()
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Returns the originating host of the request using information from the
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``HTTP_X_FORWARDED_HOST`` (if :setting:`USE_X_FORWARDED_HOST` is enabled)
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and ``HTTP_HOST`` headers, in that order. If they don't provide a value,
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the method uses a combination of ``SERVER_NAME`` and ``SERVER_PORT`` as
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detailed in :pep:`3333`.
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Example: ``"127.0.0.1:8000"``
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.. note:: The :meth:`~HttpRequest.get_host()` method fails when the host is
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behind multiple proxies. One solution is to use middleware to rewrite
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the proxy headers, as in the following example::
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class MultipleProxyMiddleware(object):
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FORWARDED_FOR_FIELDS = [
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'HTTP_X_FORWARDED_FOR',
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'HTTP_X_FORWARDED_HOST',
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'HTTP_X_FORWARDED_SERVER',
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]
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def process_request(self, request):
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"""
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Rewrites the proxy headers so that only the most
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recent proxy is used.
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"""
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for field in self.FORWARDED_FOR_FIELDS:
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if field in request.META:
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if ',' in request.META[field]:
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parts = request.META[field].split(',')
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request.META[field] = parts[-1].strip()
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This middleware should be positioned before any other middleware that
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relies on the value of :meth:`~HttpRequest.get_host()` -- for instance,
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:class:`~django.middleware.common.CommonMiddleware` or
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:class:`~django.middleware.csrf.CsrfViewMiddleware`.
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.. method:: HttpRequest.get_full_path()
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Returns the ``path``, plus an appended query string, if applicable.
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Example: ``"/music/bands/the_beatles/?print=true"``
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.. method:: HttpRequest.build_absolute_uri(location)
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Returns the absolute URI form of ``location``. If no location is provided,
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the location will be set to ``request.get_full_path()``.
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If the location is already an absolute URI, it will not be altered.
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Otherwise the absolute URI is built using the server variables available in
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this request.
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Example: ``"http://example.com/music/bands/the_beatles/?print=true"``
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.. method:: HttpRequest.get_signed_cookie(key, default=RAISE_ERROR, salt='', max_age=None)
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Returns a cookie value for a signed cookie, or raises a
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``django.core.signing.BadSignature`` exception if the signature is
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no longer valid. If you provide the ``default`` argument the exception
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will be suppressed and that default value will be returned instead.
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The optional ``salt`` argument can be used to provide extra protection
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against brute force attacks on your secret key. If supplied, the
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``max_age`` argument will be checked against the signed timestamp
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attached to the cookie value to ensure the cookie is not older than
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``max_age`` seconds.
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For example::
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>>> request.get_signed_cookie('name')
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'Tony'
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>>> request.get_signed_cookie('name', salt='name-salt')
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'Tony' # assuming cookie was set using the same salt
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>>> request.get_signed_cookie('non-existing-cookie')
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...
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KeyError: 'non-existing-cookie'
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>>> request.get_signed_cookie('non-existing-cookie', False)
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False
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>>> request.get_signed_cookie('cookie-that-was-tampered-with')
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...
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BadSignature: ...
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>>> request.get_signed_cookie('name', max_age=60)
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...
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SignatureExpired: Signature age 1677.3839159 > 60 seconds
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>>> request.get_signed_cookie('name', False, max_age=60)
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False
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See :doc:`cryptographic signing </topics/signing>` for more information.
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.. method:: HttpRequest.is_secure()
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Returns ``True`` if the request is secure; that is, if it was made with
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HTTPS.
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.. method:: HttpRequest.is_ajax()
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Returns ``True`` if the request was made via an ``XMLHttpRequest``, by
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checking the ``HTTP_X_REQUESTED_WITH`` header for the string
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``'XMLHttpRequest'``. Most modern JavaScript libraries send this header.
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If you write your own XMLHttpRequest call (on the browser side), you'll
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have to set this header manually if you want ``is_ajax()`` to work.
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.. method:: HttpRequest.read(size=None)
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.. method:: HttpRequest.readline()
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.. method:: HttpRequest.readlines()
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.. method:: HttpRequest.xreadlines()
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.. method:: HttpRequest.__iter__()
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Methods implementing a file-like interface for reading from an
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HttpRequest instance. This makes it possible to consume an incoming
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request in a streaming fashion. A common use-case would be to process a
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big XML payload with iterative parser without constructing a whole
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XML tree in memory.
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Given this standard interface, an HttpRequest instance can be
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passed directly to an XML parser such as ElementTree::
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import xml.etree.ElementTree as ET
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for element in ET.iterparse(request):
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process(element)
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UploadedFile objects
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====================
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.. class:: UploadedFile
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Attributes
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----------
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.. attribute:: UploadedFile.name
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The name of the uploaded file.
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.. attribute:: UploadedFile.size
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The size, in bytes, of the uploaded file.
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Methods
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----------
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.. method:: UploadedFile.chunks(chunk_size=None)
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Returns a generator that yields sequential chunks of data.
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.. method:: UploadedFile.read(num_bytes=None)
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Read a number of bytes from the file.
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QueryDict objects
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=================
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.. class:: QueryDict
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In an :class:`HttpRequest` object, the ``GET`` and ``POST`` attributes are instances
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of ``django.http.QueryDict``. :class:`QueryDict` is a dictionary-like
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class customized to deal with multiple values for the same key. This is
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necessary because some HTML form elements, notably
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``<select multiple="multiple">``, pass multiple values for the same key.
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``QueryDict`` instances are immutable, unless you create a ``copy()`` of them.
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That means you can't change attributes of ``request.POST`` and ``request.GET``
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directly.
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Methods
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-------
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:class:`QueryDict` implements all the standard dictionary methods, because it's
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a subclass of dictionary. Exceptions are outlined here:
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.. method:: QueryDict.__getitem__(key)
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Returns the value for the given key. If the key has more than one value,
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``__getitem__()`` returns the last value. Raises
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``django.utils.datastructures.MultiValueDictKeyError`` if the key does not
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exist. (This is a subclass of Python's standard ``KeyError``, so you can
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stick to catching ``KeyError``.)
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.. method:: QueryDict.__setitem__(key, value)
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Sets the given key to ``[value]`` (a Python list whose single element is
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``value``). Note that this, as other dictionary functions that have side
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effects, can only be called on a mutable ``QueryDict`` (one that was created
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via ``copy()``).
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.. method:: QueryDict.__contains__(key)
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Returns ``True`` if the given key is set. This lets you do, e.g., ``if "foo"
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in request.GET``.
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.. method:: QueryDict.get(key, default)
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Uses the same logic as ``__getitem__()`` above, with a hook for returning a
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default value if the key doesn't exist.
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.. method:: QueryDict.setdefault(key, default)
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Just like the standard dictionary ``setdefault()`` method, except it uses
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``__setitem__()`` internally.
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.. method:: QueryDict.update(other_dict)
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Takes either a ``QueryDict`` or standard dictionary. Just like the standard
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dictionary ``update()`` method, except it *appends* to the current
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dictionary items rather than replacing them. For example::
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>>> q = QueryDict('a=1')
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>>> q = q.copy() # to make it mutable
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>>> q.update({'a': '2'})
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>>> q.getlist('a')
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[u'1', u'2']
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>>> q['a'] # returns the last
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[u'2']
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.. method:: QueryDict.items()
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Just like the standard dictionary ``items()`` method, except this uses the
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same last-value logic as ``__getitem__()``. For example::
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>>> q = QueryDict('a=1&a=2&a=3')
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>>> q.items()
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[(u'a', u'3')]
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.. method:: QueryDict.iteritems()
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Just like the standard dictionary ``iteritems()`` method. Like
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:meth:`QueryDict.items()` this uses the same last-value logic as
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:meth:`QueryDict.__getitem__()`.
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.. method:: QueryDict.iterlists()
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Like :meth:`QueryDict.iteritems()` except it includes all values, as a list,
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for each member of the dictionary.
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.. method:: QueryDict.values()
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Just like the standard dictionary ``values()`` method, except this uses the
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same last-value logic as ``__getitem__()``. For example::
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>>> q = QueryDict('a=1&a=2&a=3')
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>>> q.values()
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[u'3']
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.. method:: QueryDict.itervalues()
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Just like :meth:`QueryDict.values()`, except an iterator.
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In addition, ``QueryDict`` has the following methods:
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.. method:: QueryDict.copy()
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Returns a copy of the object, using ``copy.deepcopy()`` from the Python
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standard library. The copy will be mutable -- that is, you can change its
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values.
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.. method:: QueryDict.getlist(key, default)
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Returns the data with the requested key, as a Python list. Returns an
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empty list if the key doesn't exist and no default value was provided.
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It's guaranteed to return a list of some sort unless the default value
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was no list.
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.. method:: QueryDict.setlist(key, list_)
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Sets the given key to ``list_`` (unlike ``__setitem__()``).
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.. method:: QueryDict.appendlist(key, item)
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Appends an item to the internal list associated with key.
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.. method:: QueryDict.setlistdefault(key, default_list)
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Just like ``setdefault``, except it takes a list of values instead of a
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single value.
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.. method:: QueryDict.lists()
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Like :meth:`items()`, except it includes all values, as a list, for each
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member of the dictionary. For example::
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>>> q = QueryDict('a=1&a=2&a=3')
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>>> q.lists()
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[(u'a', [u'1', u'2', u'3'])]
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.. method:: QueryDict.pop(key)
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Returns a list of values for the given key and removes them from the
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dictionary. Raises ``KeyError`` if the key does not exist. For example::
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>>> q = QueryDict('a=1&a=2&a=3', mutable=True)
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>>> q.pop('a')
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[u'1', u'2', u'3']
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.. method:: QueryDict.popitem()
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Removes an arbitrary member of the dictionary (since there's no concept
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of ordering), and returns a two value tuple containing the key and a list
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of all values for the key. Raises ``KeyError`` when called on an empty
|
|
dictionary. For example::
|
|
|
|
>>> q = QueryDict('a=1&a=2&a=3', mutable=True)
|
|
>>> q.popitem()
|
|
(u'a', [u'1', u'2', u'3'])
|
|
|
|
.. method:: QueryDict.dict()
|
|
|
|
Returns ``dict`` representation of ``QueryDict``. For every (key, list)
|
|
pair in ``QueryDict``, ``dict`` will have (key, item), where item is one
|
|
element of the list, using same logic as :meth:`QueryDict.__getitem__()`::
|
|
|
|
>>> q = QueryDict('a=1&a=3&a=5')
|
|
>>> q.dict()
|
|
{u'a': u'5'}
|
|
|
|
.. method:: QueryDict.urlencode([safe])
|
|
|
|
Returns a string of the data in query-string format. Example::
|
|
|
|
>>> q = QueryDict('a=2&b=3&b=5')
|
|
>>> q.urlencode()
|
|
'a=2&b=3&b=5'
|
|
|
|
Optionally, urlencode can be passed characters which
|
|
do not require encoding. For example::
|
|
|
|
>>> q = QueryDict('', mutable=True)
|
|
>>> q['next'] = '/a&b/'
|
|
>>> q.urlencode(safe='/')
|
|
'next=/a%26b/'
|
|
|
|
HttpResponse objects
|
|
====================
|
|
|
|
.. class:: HttpResponse
|
|
|
|
In contrast to :class:`HttpRequest` objects, which are created automatically by
|
|
Django, :class:`HttpResponse` objects are your responsibility. Each view you
|
|
write is responsible for instantiating, populating and returning an
|
|
:class:`HttpResponse`.
|
|
|
|
The :class:`HttpResponse` class lives in the :mod:`django.http` module.
|
|
|
|
Usage
|
|
-----
|
|
|
|
Passing strings
|
|
~~~~~~~~~~~~~~~
|
|
|
|
Typical usage is to pass the contents of the page, as a string, to the
|
|
:class:`HttpResponse` constructor::
|
|
|
|
>>> from django.http import HttpResponse
|
|
>>> response = HttpResponse("Here's the text of the Web page.")
|
|
>>> response = HttpResponse("Text only, please.", content_type="text/plain")
|
|
|
|
But if you want to add content incrementally, you can use ``response`` as a
|
|
file-like object::
|
|
|
|
>>> response = HttpResponse()
|
|
>>> response.write("<p>Here's the text of the Web page.</p>")
|
|
>>> response.write("<p>Here's another paragraph.</p>")
|
|
|
|
Passing iterators
|
|
~~~~~~~~~~~~~~~~~
|
|
|
|
Finally, you can pass ``HttpResponse`` an iterator rather than strings.
|
|
``HttpResponse`` will consume the iterator immediately, store its content as a
|
|
string, and discard it.
|
|
|
|
If you need the response to be streamed from the iterator to the client, you
|
|
must use the :class:`StreamingHttpResponse` class instead.
|
|
|
|
Setting header fields
|
|
~~~~~~~~~~~~~~~~~~~~~
|
|
|
|
To set or remove a header field in your response, treat it like a dictionary::
|
|
|
|
>>> response = HttpResponse()
|
|
>>> response['Age'] = 120
|
|
>>> del response['Age']
|
|
|
|
Note that unlike a dictionary, ``del`` doesn't raise ``KeyError`` if the header
|
|
field doesn't exist.
|
|
|
|
For setting the ``Cache-Control`` and ``Vary`` header fields, it is recommended
|
|
to use the :func:`~django.utils.cache.patch_cache_control` and
|
|
:func:`~django.utils.cache.patch_vary_headers` methods from
|
|
:mod:`django.utils.cache`, since these fields can have multiple, comma-separated
|
|
values. The "patch" methods ensure that other values, e.g. added by a
|
|
middleware, are not removed.
|
|
|
|
HTTP header fields cannot contain newlines. An attempt to set a header field
|
|
containing a newline character (CR or LF) will raise ``BadHeaderError``
|
|
|
|
Telling the browser to treat the response as a file attachment
|
|
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
|
|
|
|
To tell the browser to treat the response as a file attachment, use the
|
|
``content_type`` argument and set the ``Content-Disposition`` header. For example,
|
|
this is how you might return a Microsoft Excel spreadsheet::
|
|
|
|
>>> response = HttpResponse(my_data, content_type='application/vnd.ms-excel')
|
|
>>> response['Content-Disposition'] = 'attachment; filename="foo.xls"'
|
|
|
|
There's nothing Django-specific about the ``Content-Disposition`` header, but
|
|
it's easy to forget the syntax, so we've included it here.
|
|
|
|
Attributes
|
|
----------
|
|
|
|
.. attribute:: HttpResponse.content
|
|
|
|
A bytestring representing the content, encoded from a Unicode
|
|
object if necessary.
|
|
|
|
.. attribute:: HttpResponse.status_code
|
|
|
|
The `HTTP status code`_ for the response.
|
|
|
|
.. attribute:: HttpResponse.reason_phrase
|
|
|
|
.. versionadded:: 1.6
|
|
|
|
The HTTP reason phrase for the response.
|
|
|
|
.. attribute:: HttpResponse.streaming
|
|
|
|
This is always ``False``.
|
|
|
|
This attribute exists so middleware can treat streaming responses
|
|
differently from regular responses.
|
|
|
|
Methods
|
|
-------
|
|
|
|
.. method:: HttpResponse.__init__(content='', content_type=None, status=200, reason=None)
|
|
|
|
Instantiates an ``HttpResponse`` object with the given page content and
|
|
content type.
|
|
|
|
``content`` should be an iterator or a string. If it's an
|
|
iterator, it should return strings, and those strings will be
|
|
joined together to form the content of the response. If it is not
|
|
an iterator or a string, it will be converted to a string when
|
|
accessed.
|
|
|
|
``content_type`` is the MIME type optionally completed by a character set
|
|
encoding and is used to fill the HTTP ``Content-Type`` header. If not
|
|
specified, it is formed by the :setting:`DEFAULT_CONTENT_TYPE` and
|
|
:setting:`DEFAULT_CHARSET` settings, by default: "`text/html; charset=utf-8`".
|
|
|
|
Historically, this parameter was called ``mimetype`` (now deprecated).
|
|
|
|
``status`` is the `HTTP status code`_ for the response.
|
|
|
|
.. versionadded:: 1.6
|
|
|
|
``reason`` is the HTTP response phrase. If not provided, a default phrase
|
|
will be used.
|
|
|
|
.. method:: HttpResponse.__setitem__(header, value)
|
|
|
|
Sets the given header name to the given value. Both ``header`` and
|
|
``value`` should be strings.
|
|
|
|
.. method:: HttpResponse.__delitem__(header)
|
|
|
|
Deletes the header with the given name. Fails silently if the header
|
|
doesn't exist. Case-insensitive.
|
|
|
|
.. method:: HttpResponse.__getitem__(header)
|
|
|
|
Returns the value for the given header name. Case-insensitive.
|
|
|
|
.. method:: HttpResponse.has_header(header)
|
|
|
|
Returns ``True`` or ``False`` based on a case-insensitive check for a
|
|
header with the given name.
|
|
|
|
.. method:: HttpResponse.set_cookie(key, value='', max_age=None, expires=None, path='/', domain=None, secure=None, httponly=False)
|
|
|
|
Sets a cookie. The parameters are the same as in the :class:`Cookie.Morsel`
|
|
object in the Python standard library.
|
|
|
|
* ``max_age`` should be a number of seconds, or ``None`` (default) if
|
|
the cookie should last only as long as the client's browser session.
|
|
If ``expires`` is not specified, it will be calculated.
|
|
* ``expires`` should either be a string in the format
|
|
``"Wdy, DD-Mon-YY HH:MM:SS GMT"`` or a ``datetime.datetime`` object
|
|
in UTC. If ``expires`` is a ``datetime`` object, the ``max_age``
|
|
will be calculated.
|
|
* Use ``domain`` if you want to set a cross-domain cookie. For example,
|
|
``domain=".lawrence.com"`` will set a cookie that is readable by
|
|
the domains www.lawrence.com, blogs.lawrence.com and
|
|
calendars.lawrence.com. Otherwise, a cookie will only be readable by
|
|
the domain that set it.
|
|
* Use ``httponly=True`` if you want to prevent client-side
|
|
JavaScript from having access to the cookie.
|
|
|
|
HTTPOnly_ is a flag included in a Set-Cookie HTTP response
|
|
header. It is not part of the :rfc:`2109` standard for cookies,
|
|
and it isn't honored consistently by all browsers. However,
|
|
when it is honored, it can be a useful way to mitigate the
|
|
risk of client side script accessing the protected cookie
|
|
data.
|
|
|
|
.. _HTTPOnly: https://www.owasp.org/index.php/HTTPOnly
|
|
|
|
.. method:: HttpResponse.set_signed_cookie(key, value, salt='', max_age=None, expires=None, path='/', domain=None, secure=None, httponly=True)
|
|
|
|
Like :meth:`~HttpResponse.set_cookie()`, but
|
|
:doc:`cryptographic signing </topics/signing>` the cookie before setting
|
|
it. Use in conjunction with :meth:`HttpRequest.get_signed_cookie`.
|
|
You can use the optional ``salt`` argument for added key strength, but
|
|
you will need to remember to pass it to the corresponding
|
|
:meth:`HttpRequest.get_signed_cookie` call.
|
|
|
|
.. method:: HttpResponse.delete_cookie(key, path='/', domain=None)
|
|
|
|
Deletes the cookie with the given key. Fails silently if the key doesn't
|
|
exist.
|
|
|
|
Due to the way cookies work, ``path`` and ``domain`` should be the same
|
|
values you used in ``set_cookie()`` -- otherwise the cookie may not be
|
|
deleted.
|
|
|
|
.. method:: HttpResponse.write(content)
|
|
|
|
This method makes an :class:`HttpResponse` instance a file-like object.
|
|
|
|
.. method:: HttpResponse.flush()
|
|
|
|
This method makes an :class:`HttpResponse` instance a file-like object.
|
|
|
|
.. method:: HttpResponse.tell()
|
|
|
|
This method makes an :class:`HttpResponse` instance a file-like object.
|
|
|
|
.. _HTTP status code: http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10
|
|
|
|
.. _ref-httpresponse-subclasses:
|
|
|
|
HttpResponse subclasses
|
|
-----------------------
|
|
|
|
Django includes a number of ``HttpResponse`` subclasses that handle different
|
|
types of HTTP responses. Like ``HttpResponse``, these subclasses live in
|
|
:mod:`django.http`.
|
|
|
|
.. class:: HttpResponseRedirect
|
|
|
|
The first argument to the constructor is required -- the path to redirect
|
|
to. This can be a fully qualified URL
|
|
(e.g. ``'http://www.yahoo.com/search/'``) or an absolute path with no
|
|
domain (e.g. ``'/search/'``). See :class:`HttpResponse` for other optional
|
|
constructor arguments. Note that this returns an HTTP status code 302.
|
|
|
|
.. attribute:: HttpResponseRedirect.url
|
|
|
|
.. versionadded:: 1.6
|
|
|
|
This read-only attribute represents the URL the response will redirect
|
|
to (equivalent to the ``Location`` response header).
|
|
|
|
.. class:: HttpResponsePermanentRedirect
|
|
|
|
Like :class:`HttpResponseRedirect`, but it returns a permanent redirect
|
|
(HTTP status code 301) instead of a "found" redirect (status code 302).
|
|
|
|
.. class:: HttpResponseNotModified
|
|
|
|
The constructor doesn't take any arguments and no content should be added
|
|
to this response. Use this to designate that a page hasn't been modified
|
|
since the user's last request (status code 304).
|
|
|
|
.. class:: HttpResponseBadRequest
|
|
|
|
Acts just like :class:`HttpResponse` but uses a 400 status code.
|
|
|
|
.. class:: HttpResponseNotFound
|
|
|
|
Acts just like :class:`HttpResponse` but uses a 404 status code.
|
|
|
|
.. class:: HttpResponseForbidden
|
|
|
|
Acts just like :class:`HttpResponse` but uses a 403 status code.
|
|
|
|
.. class:: HttpResponseNotAllowed
|
|
|
|
Like :class:`HttpResponse`, but uses a 405 status code. The first argument
|
|
to the constructor is required: a list of permitted methods (e.g.
|
|
``['GET', 'POST']``).
|
|
|
|
.. class:: HttpResponseGone
|
|
|
|
Acts just like :class:`HttpResponse` but uses a 410 status code.
|
|
|
|
.. class:: HttpResponseServerError
|
|
|
|
Acts just like :class:`HttpResponse` but uses a 500 status code.
|
|
|
|
.. note::
|
|
|
|
If a custom subclass of :class:`HttpResponse` implements a ``render``
|
|
method, Django will treat it as emulating a
|
|
:class:`~django.template.response.SimpleTemplateResponse`, and the
|
|
``render`` method must itself return a valid response object.
|
|
|
|
JsonResponse objects
|
|
====================
|
|
|
|
.. versionadded:: 1.7
|
|
|
|
.. class:: JsonResponse
|
|
|
|
.. method:: JsonResponse.__init__(data, encoder=DjangoJSONEncoder, safe=True, **kwargs)
|
|
|
|
An :class:`HttpResponse` subclass that helps to create a JSON-encoded
|
|
response. It inherits most behavior from its superclass with a couple
|
|
differences:
|
|
|
|
Its default ``Content-Type`` header is set to ``application/json``.
|
|
|
|
The first parameter, ``data``, should be a ``dict`` instance. If the ``safe``
|
|
parameter is set to ``False`` (see below) it can be any JSON-serializable
|
|
object.
|
|
|
|
The ``encoder``, which defaults to
|
|
``django.core.serializers.json.DjangoJSONEncoder``, will be used to
|
|
serialize the data. See :ref:`JSON serialization
|
|
<serialization-formats-json>` for more details about this serializer.
|
|
|
|
The ``safe`` boolean parameter defaults to ``True``. If it's set to ``False``,
|
|
any object can be passed for serialization (otherwise only ``dict`` instances
|
|
are allowed). If ``safe`` is ``True`` and a non-``dict`` object is passed as
|
|
the first argument, a :exc:`~exceptions.TypeError` will be raised.
|
|
|
|
Usage
|
|
-----
|
|
|
|
Typical usage could look like::
|
|
|
|
>>> from django.http import JsonResponse
|
|
>>> response = JsonResponse({'foo': 'bar'})
|
|
>>> response.content
|
|
'{"foo": "bar"}'
|
|
|
|
|
|
Serializing non-dictionary objects
|
|
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
|
|
|
|
In order to serialize objects other than ``dict`` you must set the ``safe``
|
|
parameter to ``False``::
|
|
|
|
>>> response = JsonResponse([1, 2, 3], safe=False)
|
|
|
|
Without passing ``safe=False``, a :exc:`~exceptions.TypeError` will be raised.
|
|
|
|
.. warning::
|
|
|
|
Before the `5th edition of EcmaScript
|
|
<http://www.ecma-international.org/publications/standards/Ecma-262.htm>`_
|
|
it was possible to poison the JavaScript ``Array`` constructor. For this
|
|
reason, Django does not allow passing non-dict objects to the
|
|
:class:`~django.http.JsonResponse` constructor by default. However, most
|
|
modern browsers implement EcmaScript 5 which removes this attack vector.
|
|
Therefore it is possible to disable this security precaution.
|
|
|
|
Changing the default JSON encoder
|
|
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
|
|
|
|
If you need to use a differ JSON encoder class you can pass the ``encoder``
|
|
parameter to the constructor method::
|
|
|
|
>>> response = JsonResponse(data, encoder=MyJSONEncoder)
|
|
|
|
.. _httpresponse-streaming:
|
|
|
|
StreamingHttpResponse objects
|
|
=============================
|
|
|
|
.. class:: StreamingHttpResponse
|
|
|
|
The :class:`StreamingHttpResponse` class is used to stream a response from
|
|
Django to the browser. You might want to do this if generating the response
|
|
takes too long or uses too much memory. For instance, it's useful for
|
|
generating large CSV files.
|
|
|
|
.. admonition:: Performance considerations
|
|
|
|
Django is designed for short-lived requests. Streaming responses will tie
|
|
a worker process for the entire duration of the response. This may result
|
|
in poor performance.
|
|
|
|
Generally speaking, you should perform expensive tasks outside of the
|
|
request-response cycle, rather than resorting to a streamed response.
|
|
|
|
The :class:`StreamingHttpResponse` is not a subclass of :class:`HttpResponse`,
|
|
because it features a slightly different API. However, it is almost identical,
|
|
with the following notable differences:
|
|
|
|
* It should be given an iterator that yields strings as content.
|
|
|
|
* You cannot access its content, except by iterating the response object
|
|
itself. This should only occur when the response is returned to the client.
|
|
|
|
* It has no ``content`` attribute. Instead, it has a
|
|
:attr:`~StreamingHttpResponse.streaming_content` attribute.
|
|
|
|
* You cannot use the file-like object ``tell()`` or ``write()`` methods.
|
|
Doing so will raise an exception.
|
|
|
|
:class:`StreamingHttpResponse` should only be used in situations where it is
|
|
absolutely required that the whole content isn't iterated before transferring
|
|
the data to the client. Because the content can't be accessed, many
|
|
middlewares can't function normally. For example the ``ETag`` and ``Content-
|
|
Length`` headers can't be generated for streaming responses.
|
|
|
|
Attributes
|
|
----------
|
|
|
|
.. attribute:: StreamingHttpResponse.streaming_content
|
|
|
|
An iterator of strings representing the content.
|
|
|
|
.. attribute:: HttpResponse.status_code
|
|
|
|
The `HTTP status code`_ for the response.
|
|
|
|
.. attribute:: HttpResponse.reason_phrase
|
|
|
|
.. versionadded:: 1.6
|
|
|
|
The HTTP reason phrase for the response.
|
|
|
|
.. attribute:: HttpResponse.streaming
|
|
|
|
This is always ``True``.
|