============================================ Django 4.0 release notes - UNDER DEVELOPMENT ============================================ *Expected December 2021* Welcome to Django 4.0! These release notes cover the :ref:`new features `, as well as some :ref:`backwards incompatible changes ` you'll want to be aware of when upgrading from Django 3.2 or earlier. We've :ref:`begun the deprecation process for some features `. See the :doc:`/howto/upgrade-version` guide if you're updating an existing project. Python compatibility ==================== Django 4.0 supports Python 3.8, 3.9, and 3.10. We **highly recommend** and only officially support the latest release of each series. The Django 3.2.x series is the last to support Python 3.6 and 3.7. .. _whats-new-4.0: What's new in Django 4.0 ======================== Minor features -------------- :mod:`django.contrib.admin` ~~~~~~~~~~~~~~~~~~~~~~~~~~~ * The ``admin/base.html`` template now has a new block ``header`` which contains the admin site header. :mod:`django.contrib.admindocs` ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ * The admindocs now allows esoteric setups where :setting:`ROOT_URLCONF` is not a string. :mod:`django.contrib.auth` ~~~~~~~~~~~~~~~~~~~~~~~~~~ * The default iteration count for the PBKDF2 password hasher is increased from 260,000 to 320,000. * The new :attr:`LoginView.next_page ` attribute and :meth:`~django.contrib.auth.views.LoginView.get_default_redirect_url` method allow customizing the redirect after login. :mod:`django.contrib.contenttypes` ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ * ... :mod:`django.contrib.gis` ~~~~~~~~~~~~~~~~~~~~~~~~~ * ... :mod:`django.contrib.messages` ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ * ... :mod:`django.contrib.postgres` ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ * The PostgreSQL backend now supports connecting by a service name. See :ref:`postgresql-connection-settings` for more details. :mod:`django.contrib.redirects` ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ * ... :mod:`django.contrib.sessions` ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ * ... :mod:`django.contrib.sitemaps` ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ * ... :mod:`django.contrib.sites` ~~~~~~~~~~~~~~~~~~~~~~~~~~~ * ... :mod:`django.contrib.staticfiles` ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ * ... :mod:`django.contrib.syndication` ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ * ... Cache ~~~~~ * ... CSRF ~~~~ * ... Decorators ~~~~~~~~~~ * ... Email ~~~~~ * ... Error Reporting ~~~~~~~~~~~~~~~ * ... File Storage ~~~~~~~~~~~~ * ... File Uploads ~~~~~~~~~~~~ * ... Forms ~~~~~ * :class:`~django.forms.ModelChoiceField` now includes the provided value in the ``params`` argument of a raised :exc:`~django.core.exceptions.ValidationError` for the ``invalid_choice`` error message. This allows custom error messages to use the ``%(value)s`` placeholder. Generic Views ~~~~~~~~~~~~~ * ... Internationalization ~~~~~~~~~~~~~~~~~~~~ * ... Logging ~~~~~~~ * ... Management Commands ~~~~~~~~~~~~~~~~~~~ * The :djadmin:`runserver` management command now supports the :option:`--skip-checks` option. Migrations ~~~~~~~~~~ * ... Models ~~~~~~ * ... Requests and Responses ~~~~~~~~~~~~~~~~~~~~~~ * ... Security ~~~~~~~~ * ... Serialization ~~~~~~~~~~~~~ * ... Signals ~~~~~~~ * The new ``stdout`` argument for :func:`~django.db.models.signals.pre_migrate` and :func:`~django.db.models.signals.post_migrate` signals allows redirecting output to a stream-like object. It should be preferred over :py:data:`sys.stdout` and :py:func:`print` when emitting verbose output in order to allow proper capture when testing. Templates ~~~~~~~~~ * ... Tests ~~~~~ * ... URLs ~~~~ * ... Utilities ~~~~~~~~~ * ... Validators ~~~~~~~~~~ * ... .. _backwards-incompatible-4.0: Backwards incompatible changes in 4.0 ===================================== Database backend API -------------------- This section describes changes that may be needed in third-party database backends. * ... :mod:`django.contrib.gis` ------------------------- * Support for PostGIS 2.3 is removed. Dropped support for PostgreSQL 9.6 ---------------------------------- Upstream support for PostgreSQL 9.6 ends in November 2021. Django 4.0 supports PostgreSQL 10 and higher. Dropped support for Oracle 12.2 and 18c --------------------------------------- Upstream support for Oracle 12.2 ends in March 2022 and for Oracle 18c it ends in June 2021. Django 3.2 will be supported until April 2024. Django 4.0 officially supports Oracle 19c. Miscellaneous ------------- * Support for ``cx_Oracle`` < 7.0 is removed. * Starting with 4.0, new projects are generated with :setting:`STATIC_URL` set to the relative path ``'static/'``. This allows for the ``SCRIPT_NAME`` to be prepended as necessary. .. _deprecated-features-4.0: Features deprecated in 4.0 ========================== Miscellaneous ------------- * ... Features removed in 4.0 ======================= These features have reached the end of their deprecation cycle and are removed in Django 4.0. See :ref:`deprecated-features-3.0` for details on these changes, including how to remove usage of these features. * ``django.utils.http.urlquote()``, ``urlquote_plus()``, ``urlunquote()``, and ``urlunquote_plus()`` are removed. * ``django.utils.encoding.force_text()`` and ``smart_text()`` are removed. * ``django.utils.translation.ugettext()``, ``ugettext_lazy()``, ``ugettext_noop()``, ``ungettext()``, and ``ungettext_lazy()`` are removed. * ``django.views.i18n.set_language()`` doesn't set the user language in ``request.session`` (key ``_language``). * ``alias=None`` is required in the signature of ``django.db.models.Expression.get_group_by_cols()`` subclasses. * ``django.utils.text.unescape_entities()`` is removed. * ``django.utils.http.is_safe_url()`` is removed. See :ref:`deprecated-features-3.1` for details on these changes, including how to remove usage of these features. * The ``PASSWORD_RESET_TIMEOUT_DAYS`` setting is removed. * The :lookup:`isnull` lookup no longer allows using non-boolean values as the right-hand side. * The ``django.db.models.query_utils.InvalidQuery`` exception class is removed. * The ``django-admin.py`` entry point is removed. * The ``HttpRequest.is_ajax()`` method is removed. * Support for the pre-Django 3.1 encoding format of cookies values used by ``django.contrib.messages.storage.cookie.CookieStorage`` is removed. * Support for the pre-Django 3.1 password reset tokens in the admin site (that use the SHA-1 hashing algorithm) is removed. * Support for the pre-Django 3.1 encoding format of sessions is removed. * Support for the pre-Django 3.1 ``django.core.signing.Signer`` signatures (encoded with the SHA-1 algorithm) is removed. * Support for the pre-Django 3.1 ``django.core.signing.dumps()`` signatures (encoded with the SHA-1 algorithm) in ``django.core.signing.loads()`` is removed. * Support for the pre-Django 3.1 user sessions (that use the SHA-1 algorithm) is removed. * The ``get_request`` argument for ``django.utils.deprecation.MiddlewareMixin.__init__()`` is required and doesn't accept ``None``. * The ``providing_args`` argument for ``django.dispatch.Signal`` is removed. * The ``length`` argument for ``django.utils.crypto.get_random_string()`` is required. * The ``list`` message for ``ModelMultipleChoiceField`` is removed. * Support for passing raw column aliases to ``QuerySet.order_by()`` is removed. * The ``NullBooleanField`` model field is removed, except for support in historical migrations. * ``django.conf.urls.url()`` is removed. * The ``django.contrib.postgres.fields.JSONField`` model field is removed, except for support in historical migrations. * ``django.contrib.postgres.fields.jsonb.KeyTransform`` and ``django.contrib.postgres.fields.jsonb.KeyTextTransform`` are removed. * ``django.contrib.postgres.forms.JSONField`` is removed. * The ``{% ifequal %}`` and ``{% ifnotequal %}`` template tags are removed. * The ``DEFAULT_HASHING_ALGORITHM`` transitional setting is removed.