django/docs/topics/http/decorators.txt

===============
View decorators
===============

.. currentmodule:: django.views.decorators.http

Django provides several decorators that can be applied to views to support
various HTTP features.

Allowed HTTP methods
====================

.. function:: require_http_methods(request_method_list)

This decorator is used to make a view only accept particular request methods.
Usage::

    from django.views.decorators.http import require_http_methods
    @require_http_methods(["GET", "POST"])
    def my_view(request):
        # I can assume now that only GET or POST requests make it this far
        # ...
        pass

Note that request methods should be in uppercase.

.. function:: require_GET()

Decorator to require that a view only accept the GET method.

.. function:: require_POST()

Decorator to require that a view only accept the POST method.

Conditional view processing
===========================

.. function:: condition(etag_func=None, last_modified_func=None)

.. function:: etag(etag_func)

.. function:: last_modified(last_modified_func)

These decorators can be used to generate ``ETag`` and ``Last-Modified``
headers; see
:doc:`conditional view processing </topics/conditional-view-processing>`.

.. currentmodule:: django.views.decorators.http

GZip compression
================

.. function:: gzip_page()

This decorator compresses content if the browser allows gzip compression.
It sets the ``Vary`` header accordingly, so that caches will base their
storage on the ``Accept-Encoding`` header.

.. currentmodule:: django.views.decorators.vary

Vary headers
============

The ``Vary`` header defines which request headers a cache mechanism should take
into account when building its cache key.

.. function:: vary_on_cookie(func)

.. function:: vary_on_headers(*headers)

See :ref:`using vary headers <using-vary-headers>`.