View decorators

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

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

Allowed HTTP methods

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

• requirehttp_methods(_request_method_list)
• Decorator to require that a view only accepts particular requestmethods. 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 havethe significance of taking an action other than retrieving the requestedresource.

Note

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

Conditional view processing

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

• condition(etag_func=None, last_modified_func=None)
• etag(etag_func)
• lastmodified(_last_modified_func)
• These decorators can be used to generate ETag and Last-Modifiedheaders; seeconditional view processing.

GZip compression

The decorators in django.views.decorators.gzip control contentcompression 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 theirstorage on the Accept-Encoding header.

Vary headers

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

• varyon_cookie(_func)
• varyon_headers(*headers_)
• The Vary header defines which request headers a cache mechanism should takeinto account when building its cache key.

See using vary headers.

Caching

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

• cachecontrol(**kwargs_)

• This decorator patches the response’s Cache-Control header by addingall of the keyword arguments to it. Seepatch_cache_control() for the details of thetransformation.

• nevercache(_view_func)

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

Changed in Django 3.0:private directive was added.