View decorators

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

See Decorating the class for how to use these decorators with class-based views.

Allowed HTTP methods

The decorators in django.views.decorators.http can be used to restrict access to views based on the request method. These decorators will return a django.http.HttpResponseNotAllowed if the conditions are not met.

require_http_methods(request_method_list)

Decorator to require that a view only accepts 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.

require_GET()

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

require_POST()

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

require_safe()

Decorator to require that a view only accepts the GET and HEAD methods. These methods are commonly considered “safe” because they should not have the significance of taking an action other than retrieving the requested resource.

Note

Web servers should automatically strip the content of responses to HEAD requests while leaving the headers unchanged, so you may handle HEAD requests exactly like GET requests in your views. Since some software, such as link checkers, rely on HEAD requests, you might prefer using require_safe instead of require_GET.

Conditional view processing

The following decorators in django.views.decorators.http can be used to control caching behavior on particular views.

condition(etag_func=None, last_modified_func=None)

etag(etag_func)

last_modified(last_modified_func)

These decorators can be used to generate ETag and Last-Modified headers; see conditional view processing.

GZip compression

The decorators in django.views.decorators.gzip control content compression on a per-view basis.

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.

Vary headers

The decorators in django.views.decorators.vary can be used to control caching based on specific request headers.

vary_on_cookie(func)

vary_on_headers(*headers)

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

See using vary headers.

Caching

The decorators in django.views.decorators.cache control server and client-side caching.

cache_control(**kwargs)

This decorator patches the response’s Cache-Control header by adding all of the keyword arguments to it. See patch_cache_control() for the details of the transformation.

never_cache(view_func)

This decorator adds an Expires header to the current date/time.

This decorator adds a Cache-Control: max-age=0, no-cache, no-store, must-revalidate, private header to a response to indicate that a page should never be cached.

Each header is only added if it isn’t already set.

Common

The decorators in django.views.decorators.common allow per-view customization of CommonMiddleware behavior.

no_append_slash()

This decorator allows individual views to be excluded from APPEND_SLASH URL normalization.