Fixed #14512 -- Added documentation on how to apply decorators to class-based generic views. Thanks to Łukasz Rekucki for his work on the issue.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@14642 bcc190cf-cafb-0310-a4f2-bffc1f526a37
This commit is contained in:
Russell Keith-Magee 2010-11-20 05:10:13 +00:00
parent ec7c49f253
commit 591ad8afbf
3 changed files with 63 additions and 9 deletions

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@ -1,11 +1,15 @@
"Functions that help with dynamically creating decorators for views."
import types
try:
from functools import wraps, update_wrapper, WRAPPER_ASSIGNMENTS
except ImportError:
from django.utils.functional import wraps, update_wrapper, WRAPPER_ASSIGNMENTS # Python 2.4 fallback.
class classonlymethod(classmethod):
def __get__(self, instance, owner):
if instance is not None:
raise AttributeError("This method is available only on the view class.")
return super(classonlymethod, self).__get__(instance, owner)
def method_decorator(decorator):
"""

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@ -1,19 +1,12 @@
import copy
from django import http
from django.core.exceptions import ImproperlyConfigured
from django.template import RequestContext, loader
from django.utils.translation import ugettext_lazy as _
from django.utils.functional import update_wrapper
from django.utils.log import getLogger
from django.utils.decorators import classonlymethod
logger = getLogger('django.request')
class classonlymethod(classmethod):
def __get__(self, instance, owner):
if instance is not None:
raise AttributeError("This method is available only on the view class.")
return super(classonlymethod, self).__get__(instance, owner)
class View(object):
"""
Intentionally simple parent class for all views. Only implements

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@ -537,3 +537,60 @@ Because of the way that Python resolves method overloading, the local
:func:`render_to_response()` implementation will override the
versions provided by :class:`JSONResponseMixin` and
:class:`~django.views.generic.detail.SingleObjectTemplateResponseMixin`.
Decorating class-based views
============================
.. highlightlang:: python
The extension of class-based views isn't limited to using mixins. You
can use also use decorators.
Decorating in URLconf
---------------------
The simplest way of decorating class-based views is to decorate the
result of the :meth:`~django.views.generic.base.View.as_view` method.
The easiest place to do this is in the URLconf where you deploy your
view::
from django.contrib.auth.decorators import login_required
from django.views.generic import TemplateView
urlpatterns = patterns('',
(r'^about/',login_required(TemplateView.as_view(template_name="secret.html"))),
)
This approach applies the decorator on a per-instance basis. If you
want every instance of a view to be decorated, you need to take a
different approach.
Decorating the class
--------------------
To decorate every instance of a class-based view, you need to decorate
the class definition itself. To do this you apply the decorator to one
of the view-like methods on the class; that is,
:meth:`~django.views.generic.base.View.dispatch`, or one of the HTTP
methods (:meth:`~django.views.generic.base.View.get`,
:meth:`~django.views.generic.base.View.post` etc).
A method on a class isn't quite the same as a standalone function, so
you can't just apply a function decorator to the method -- you need to
transform it into a method decorator first. The ``method_decorator``
decorator transforms a function decorator into a method decorator so
that it can be used on an instance method.
from django.contrib.auth.decorators import login_required
from django.utils.decorators import method_decorator
from django.views.generic import TemplateView
class ProtectedView(TemplateView):
template_name = 'secret.html'
@method_decorator(login_required)
def dispatch(self, **kwargs):
return super(ProtectedView, self).dispatch(**kwargs)
In this example, every instance of :class:`ProtectedView` will have
login protection.