mirror of https://github.com/django/django.git
119 lines
3.6 KiB
Plaintext
119 lines
3.6 KiB
Plaintext
===============
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View decorators
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===============
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.. module:: django.views.decorators.http
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Django provides several decorators that can be applied to views to support
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various HTTP features.
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Allowed HTTP methods
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====================
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The decorators in :mod:`django.views.decorators.http` can be used to restrict
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access to views based on the request method. These decorators will return
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a :class:`django.http.HttpResponseNotAllowed` if the conditions are not met.
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.. function:: require_http_methods(request_method_list)
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Decorator to require that a view only accepts particular request
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methods. Usage::
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from django.views.decorators.http import require_http_methods
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@require_http_methods(["GET", "POST"])
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def my_view(request):
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# I can assume now that only GET or POST requests make it this far
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# ...
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pass
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Note that request methods should be in uppercase.
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.. function:: require_GET()
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Decorator to require that a view only accepts the GET method.
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.. function:: require_POST()
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Decorator to require that a view only accepts the POST method.
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.. function:: require_safe()
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Decorator to require that a view only accepts the GET and HEAD methods.
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These methods are commonly considered "safe" because they should not have
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the significance of taking an action other than retrieving the requested
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resource.
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.. note::
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Web servers should automatically strip the content of responses to HEAD
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requests while leaving the headers unchanged, so you may handle HEAD
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requests exactly like GET requests in your views. Since some software,
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such as link checkers, rely on HEAD requests, you might prefer
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using ``require_safe`` instead of ``require_GET``.
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Conditional view processing
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===========================
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The following decorators in :mod:`django.views.decorators.http` can be used to
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control caching behavior on particular views.
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.. function:: condition(etag_func=None, last_modified_func=None)
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.. function:: etag(etag_func)
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.. function:: last_modified(last_modified_func)
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These decorators can be used to generate ``ETag`` and ``Last-Modified``
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headers; see
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:doc:`conditional view processing </topics/conditional-view-processing>`.
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.. module:: django.views.decorators.gzip
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GZip compression
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================
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The decorators in :mod:`django.views.decorators.gzip` control content
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compression on a per-view basis.
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.. function:: gzip_page()
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This decorator compresses content if the browser allows gzip compression.
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It sets the ``Vary`` header accordingly, so that caches will base their
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storage on the ``Accept-Encoding`` header.
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.. module:: django.views.decorators.vary
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Vary headers
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============
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The decorators in :mod:`django.views.decorators.vary` can be used to control
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caching based on specific request headers.
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.. function:: vary_on_cookie(func)
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.. function:: vary_on_headers(*headers)
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The ``Vary`` header defines which request headers a cache mechanism should take
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into account when building its cache key.
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See :ref:`using vary headers <using-vary-headers>`.
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.. module:: django.views.decorators.cache
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Caching
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=======
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The decorators in :mod:`django.views.decorators.cache` control server and
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client-side caching.
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.. function:: never_cache(view_func)
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This decorator adds a ``Cache-Control: max-age=0, no-cache, no-store,
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must-revalidate`` header to a response to indicate that a page should never
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be cached.
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.. versionchanged:: 1.9
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Before Django 1.9, ``Cache-Control: max-age=0`` was sent. This didn't
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reliably prevent caching in all browsers.
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