mirror of
https://github.com/django/django.git
synced 2024-12-23 09:36:06 +00:00
df41b5a05d
Thanks Aymeric Augustin for shepherding the DEP and patch review. Thanks Marten Kenbeek and Tim Graham for contributing to the code. Thanks Tom Christie, Shai Berger, and Tim Graham for the docs.
209 lines
7.1 KiB
Plaintext
209 lines
7.1 KiB
Plaintext
=================================
|
|
``django.urls`` utility functions
|
|
=================================
|
|
|
|
.. module:: django.urls
|
|
|
|
``reverse()``
|
|
=============
|
|
|
|
If you need to use something similar to the :ttag:`url` template tag in
|
|
your code, Django provides the following function:
|
|
|
|
.. function:: reverse(viewname, urlconf=None, args=None, kwargs=None, current_app=None)
|
|
|
|
``viewname`` can be a :ref:`URL pattern name <naming-url-patterns>` or the
|
|
callable view object. For example, given the following ``url``::
|
|
|
|
from news import views
|
|
|
|
path('archive/', views.archive, name='news-archive')
|
|
|
|
you can use any of the following to reverse the URL::
|
|
|
|
# using the named URL
|
|
reverse('news-archive')
|
|
|
|
# passing a callable object
|
|
# (This is discouraged because you can't reverse namespaced views this way.)
|
|
from news import views
|
|
reverse(views.archive)
|
|
|
|
If the URL accepts arguments, you may pass them in ``args``. For example::
|
|
|
|
from django.urls import reverse
|
|
|
|
def myview(request):
|
|
return HttpResponseRedirect(reverse('arch-summary', args=[1945]))
|
|
|
|
You can also pass ``kwargs`` instead of ``args``. For example::
|
|
|
|
>>> reverse('admin:app_list', kwargs={'app_label': 'auth'})
|
|
'/admin/auth/'
|
|
|
|
``args`` and ``kwargs`` cannot be passed to ``reverse()`` at the same time.
|
|
|
|
If no match can be made, ``reverse()`` raises a
|
|
:class:`~django.urls.NoReverseMatch` exception.
|
|
|
|
The ``reverse()`` function can reverse a large variety of regular expression
|
|
patterns for URLs, but not every possible one. The main restriction at the
|
|
moment is that the pattern cannot contain alternative choices using the
|
|
vertical bar (``"|"``) character. You can quite happily use such patterns for
|
|
matching against incoming URLs and sending them off to views, but you cannot
|
|
reverse such patterns.
|
|
|
|
The ``current_app`` argument allows you to provide a hint to the resolver
|
|
indicating the application to which the currently executing view belongs.
|
|
This ``current_app`` argument is used as a hint to resolve application
|
|
namespaces into URLs on specific application instances, according to the
|
|
:ref:`namespaced URL resolution strategy <topics-http-reversing-url-namespaces>`.
|
|
|
|
The ``urlconf`` argument is the URLconf module containing the URL patterns to
|
|
use for reversing. By default, the root URLconf for the current thread is used.
|
|
|
|
.. note::
|
|
|
|
The string returned by ``reverse()`` is already
|
|
:ref:`urlquoted <uri-and-iri-handling>`. For example::
|
|
|
|
>>> reverse('cities', args=['Orléans'])
|
|
'.../Orl%C3%A9ans/'
|
|
|
|
Applying further encoding (such as :func:`urllib.parse.quote`) to the output
|
|
of ``reverse()`` may produce undesirable results.
|
|
|
|
``reverse_lazy()``
|
|
==================
|
|
|
|
A lazily evaluated version of `reverse()`_.
|
|
|
|
.. function:: reverse_lazy(viewname, urlconf=None, args=None, kwargs=None, current_app=None)
|
|
|
|
It is useful for when you need to use a URL reversal before your project's
|
|
URLConf is loaded. Some common cases where this function is necessary are:
|
|
|
|
* providing a reversed URL as the ``url`` attribute of a generic class-based
|
|
view.
|
|
|
|
* providing a reversed URL to a decorator (such as the ``login_url`` argument
|
|
for the :func:`django.contrib.auth.decorators.permission_required`
|
|
decorator).
|
|
|
|
* providing a reversed URL as a default value for a parameter in a function's
|
|
signature.
|
|
|
|
``resolve()``
|
|
=============
|
|
|
|
The ``resolve()`` function can be used for resolving URL paths to the
|
|
corresponding view functions. It has the following signature:
|
|
|
|
.. function:: resolve(path, urlconf=None)
|
|
|
|
``path`` is the URL path you want to resolve. As with
|
|
:func:`~django.urls.reverse`, you don't need to worry about the ``urlconf``
|
|
parameter. The function returns a :class:`ResolverMatch` object that allows you
|
|
to access various metadata about the resolved URL.
|
|
|
|
If the URL does not resolve, the function raises a
|
|
:exc:`~django.urls.Resolver404` exception (a subclass of
|
|
:class:`~django.http.Http404`) .
|
|
|
|
.. class:: ResolverMatch
|
|
|
|
.. attribute:: ResolverMatch.func
|
|
|
|
The view function that would be used to serve the URL
|
|
|
|
.. attribute:: ResolverMatch.args
|
|
|
|
The arguments that would be passed to the view function, as
|
|
parsed from the URL.
|
|
|
|
.. attribute:: ResolverMatch.kwargs
|
|
|
|
The keyword arguments that would be passed to the view
|
|
function, as parsed from the URL.
|
|
|
|
.. attribute:: ResolverMatch.url_name
|
|
|
|
The name of the URL pattern that matches the URL.
|
|
|
|
.. attribute:: ResolverMatch.app_name
|
|
|
|
The application namespace for the URL pattern that matches the
|
|
URL.
|
|
|
|
.. attribute:: ResolverMatch.app_names
|
|
|
|
The list of individual namespace components in the full
|
|
application namespace for the URL pattern that matches the URL.
|
|
For example, if the ``app_name`` is ``'foo:bar'``, then ``app_names``
|
|
will be ``['foo', 'bar']``.
|
|
|
|
.. attribute:: ResolverMatch.namespace
|
|
|
|
The instance namespace for the URL pattern that matches the
|
|
URL.
|
|
|
|
.. attribute:: ResolverMatch.namespaces
|
|
|
|
The list of individual namespace components in the full
|
|
instance namespace for the URL pattern that matches the URL.
|
|
i.e., if the namespace is ``foo:bar``, then namespaces will be
|
|
``['foo', 'bar']``.
|
|
|
|
.. attribute:: ResolverMatch.view_name
|
|
|
|
The name of the view that matches the URL, including the namespace if
|
|
there is one.
|
|
|
|
A :class:`ResolverMatch` object can then be interrogated to provide
|
|
information about the URL pattern that matches a URL::
|
|
|
|
# Resolve a URL
|
|
match = resolve('/some/path/')
|
|
# Print the URL pattern that matches the URL
|
|
print(match.url_name)
|
|
|
|
A :class:`ResolverMatch` object can also be assigned to a triple::
|
|
|
|
func, args, kwargs = resolve('/some/path/')
|
|
|
|
One possible use of :func:`~django.urls.resolve` would be to test whether a
|
|
view would raise a ``Http404`` error before redirecting to it::
|
|
|
|
from urllib.parse import urlparse
|
|
from django.urls import resolve
|
|
from django.http import HttpResponseRedirect, Http404
|
|
|
|
def myview(request):
|
|
next = request.META.get('HTTP_REFERER', None) or '/'
|
|
response = HttpResponseRedirect(next)
|
|
|
|
# modify the request and response as required, e.g. change locale
|
|
# and set corresponding locale cookie
|
|
|
|
view, args, kwargs = resolve(urlparse(next)[2])
|
|
kwargs['request'] = request
|
|
try:
|
|
view(*args, **kwargs)
|
|
except Http404:
|
|
return HttpResponseRedirect('/')
|
|
return response
|
|
|
|
``get_script_prefix()``
|
|
=======================
|
|
|
|
.. function:: get_script_prefix()
|
|
|
|
Normally, you should always use :func:`~django.urls.reverse` to define URLs
|
|
within your application. However, if your application constructs part of the
|
|
URL hierarchy itself, you may occasionally need to generate URLs. In that
|
|
case, you need to be able to find the base URL of the Django project within
|
|
its Web server (normally, :func:`~django.urls.reverse` takes care of this for
|
|
you). In that case, you can call ``get_script_prefix()``, which will return
|
|
the script prefix portion of the URL for your Django project. If your Django
|
|
project is at the root of its web server, this is always ``"/"``.
|