============================================
Django 1.9 release notes - UNDER DEVELOPMENT
============================================

Welcome to Django 1.9!

These release notes cover the `new features`_, as well as some `backwards
incompatible changes`_ you'll want to be aware of when upgrading from Django
1.8 or older versions. We've :ref:`dropped some features
<deprecation-removed-in-1.9>` that have reached the end of their deprecation
cycle, and we've `begun the deprecation process for some features`_.

.. _`new features`: `What's new in Django 1.9`_
.. _`backwards incompatible changes`: `Backwards incompatible changes in 1.9`_
.. _`dropped some features`: `Features removed in 1.9`_
.. _`begun the deprecation process for some features`: `Features deprecated in 1.9`_

Python compatibility
====================

Like Django 1.8, Django 1.9 requires Python 2.7 or above, though we
**highly recommend** the latest minor release. We've dropped support for
Python 3.2 and added support for Python 3.5.

What's new in Django 1.9
========================

...

Minor features
~~~~~~~~~~~~~~

:mod:`django.contrib.admin`
^^^^^^^^^^^^^^^^^^^^^^^^^^^

* Admin views now have ``model_admin`` or ``admin_site`` attributes.

* The URL of the admin change view has been changed (was at
  ``/admin/<app>/<model>/<pk>/`` by default and is now at
  ``/admin/<app>/<model>/<pk>/change/``). This should not affect your
  application unless you have hardcoded admin URLs. In that case, replace those
  links by :ref:`reversing admin URLs <admin-reverse-urls>` instead. Note that
  the old URL still redirects to the new one for backwards compatibility, but
  it may be removed in a future version.

:mod:`django.contrib.auth`
^^^^^^^^^^^^^^^^^^^^^^^^^^

* The default iteration count for the PBKDF2 password hasher has been increased
  by 20%. This backwards compatible change will not affect users who have
  subclassed ``django.contrib.auth.hashers.PBKDF2PasswordHasher`` to change the
  default value.

:mod:`django.contrib.gis`
^^^^^^^^^^^^^^^^^^^^^^^^^^

* ...

:mod:`django.contrib.messages`
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

* ...

: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
^^^^^

* ``django.core.cache.backends.base.BaseCache`` now has a ``get_or_set()``
  method.

Email
^^^^^

* ...

File Storage
^^^^^^^^^^^^

* ...

File Uploads
^^^^^^^^^^^^

* ...

Forms
^^^^^

* :class:`~django.forms.ModelForm` accepts the new ``Meta`` option
  ``field_classes`` to customize the type of the fields. See
  :ref:`modelforms-overriding-default-fields` for details.

* You can now specify the order in which form fields are rendered with the
  :attr:`~django.forms.Form.field_order` attribute, the ``field_order``
  constructor argument , or the :meth:`~django.forms.Form.order_fields` method.

Generic Views
^^^^^^^^^^^^^

* Class based views generated using ``as_view()`` now have ``view_class``
  and ``view_initkwargs`` attributes.

Internationalization
^^^^^^^^^^^^^^^^^^^^

* The :func:`django.views.i18n.set_language` view now properly redirects to
  :ref:`translated URLs <url-internationalization>`, when available.

Management Commands
^^^^^^^^^^^^^^^^^^^

* ...

Models
^^^^^^

* Added the :meth:`RelatedManager.set()
  <django.db.models.fields.related.RelatedManager.set()>` method to the related
  managers created by ``ForeignKey``, ``GenericForeignKey``, and
  ``ManyToManyField``.

CSRF
^^^^

* The request header's name used for CSRF authentication can be customized
  with :setting:`CSRF_HEADER_NAME`.

Signals
^^^^^^^

* ...

Templates
^^^^^^^^^

* Template tags created with the :meth:`~django.template.Library.simple_tag`
  helper can now store results in a template variable by using the ``as``
  argument.

Requests and Responses
^^^^^^^^^^^^^^^^^^^^^^

* Unless :attr:`HttpResponse.reason_phrase
  <django.http.HttpResponse.reason_phrase>` is explicitly set, it now is
  determined by the current value of :attr:`HttpResponse.status_code
  <django.http.HttpResponse.status_code>`. Modifying the value of
  ``status_code`` outside of the constructor will also modify the value of
  ``reason_phrase``.

* The debug view now shows details of chained exceptions on Python 3.

Tests
^^^^^

* ...

Validators
^^^^^^^^^^

* ...

Backwards incompatible changes in 1.9
=====================================

.. warning::

    In addition to the changes outlined in this section, be sure to review the
    :doc:`deprecation timeline </internals/deprecation>` for any features that
    have been removed. If you haven't updated your code within the
    deprecation timeline for a given feature, its removal may appear as a
    backwards incompatible change.

Database backend API
~~~~~~~~~~~~~~~~~~~~

* A couple of new tests rely on the ability of the backend to introspect column
  defaults (returning the result as ``Field.default``). You can set the
  ``can_introspect_default`` database feature to ``False`` if your backend
  doesn't implement this. You may want to review the implementation on the
  backends that Django includes for reference (:ticket:`24245`).

Default settings that were tuples are now lists
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

The default settings in ``django.conf.global_settings`` were a combination of
lists and tuples. All settings that were formerly tuples are now lists.

``is_usable`` attribute on template loaders is removed
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Django template loaders previously required an ``is_usable`` attribute to be
defined. If a loader was configured in the template settings and this attribute
was ``False``, the loader would be silently ignored. In practice, this was only
used by the egg loader to detect if setuptools was installed. The ``is_usable``
attribute is now removed and the egg loader instead fails at runtime if
setuptools is not installed.

Related set direct assignment
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

:ref:`Direct assignment <direct-assignment>`) used to perform a ``clear()``
followed by a call to ``add()``. This caused needlessly large data changes
and prevented using the :data:`~django.db.models.signals.m2m_changed` signal
to track individual changes in many-to-many relations.

Direct assignment now relies on the the new
:meth:`django.db.models.fields.related.RelatedManager.set()` method on
related managers which by default only processes changes between the
existing related set and the one that's newly assigned. The previous behavior
can be restored by replacing direct assignment by a call to ``set()`` with
the keyword argument ``clear=True``.

``ModelForm``, and therefore ``ModelAdmin``, internally rely on direct
assignment for many-to-many relations and as a consequence now use the new
behavior.

Filesystem-based template loaders catch more specific exceptions
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

When using the :class:`filesystem.Loader <django.template.loaders.filesystem.Loader>`
or :class:`app_directories.Loader <django.template.loaders.app_directories.Loader>`
template loaders, earlier versions of Django raised a
:exc:`~django.template.TemplateDoesNotExist` error if a template source existed
but was unreadable. This could happen under many circumstances, such as if
Django didn't have permissions to open the file, or if the template source was
a directory. Now, Django only silences the exception if the template source
does not exist. All other situations result in the original ``IOError`` being
raised.

Miscellaneous
~~~~~~~~~~~~~

* CSS and images in ``contrib.admin`` to support Internet Explorer 6 & 7 have
  been removed as these browsers have reached end-of-life.

* The text displayed for null columns in the admin changelist ``list_display``
  cells has changed from ``(None)`` (or its translated equivalent) to ``-``.

* ``django.http.responses.REASON_PHRASES`` and
  ``django.core.handlers.wsgi.STATUS_CODE_TEXT`` have been removed. Use
  Python's stdlib instead: :data:`http.client.responses` for Python 3 and
  `httplib.responses`_ for Python 2.

  .. _`httplib.responses`: https://docs.python.org/2/library/httplib.html#httplib.responses

* ``ValuesQuerySet`` and ``ValuesListQuerySet`` have been removed.

* The ``admin/base.html`` template no longer sets
  ``window.__admin_media_prefix__``. Image references in JavaScript that used
  that value to construct absolute URLs have been moved to CSS for easier
  customization.

.. _deprecated-features-1.9:

Features deprecated in 1.9
==========================

``assignment_tag()``
~~~~~~~~~~~~~~~~~~~~

Django 1.4 added the ``assignment_tag`` helper to ease the creation of
template tags that store results in a template variable. The
:meth:`~django.template.Library.simple_tag` helper has gained this same
ability, making the ``assignment_tag`` obsolete. Tags that use
``assignment_tag`` should be updated to use ``simple_tag``.

``{% cycle %}`` syntax with comma-separated arguments
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

The :ttag:`cycle` tag supports an inferior old syntax from previous Django
versions:

.. code-block:: html+django

    {% cycle row1,row2,row3 %}

Its parsing caused bugs with the current syntax, so support for the old syntax
will be removed in Django 2.0 following an accelerated deprecation.

Miscellaneous
~~~~~~~~~~~~~

* The ``weak`` argument to ``django.dispatch.signals.Signal.disconnect()`` has
  been deprecated as it has no effect.

* The ``check_aggregate_support()`` method of
  ``django.db.backends.base.BaseDatabaseOperations`` has been deprecated and
  will be removed in Django 2.1. The more general ``check_expression_support()``
  should be used instead.

* ``django.forms.extras`` is deprecated. You can find
  :class:`~django.forms.SelectDateWidget` in ``django.forms.widgets``
  (or simply ``django.forms``) instead.

.. removed-features-1.9:

Features removed in 1.9
=======================

These features have reached the end of their deprecation cycle and so have been
removed in Django 1.9 (please see the :ref:`deprecation timeline
<deprecation-removed-in-1.9>` for more details):

* ``django.utils.dictconfig`` is removed.

* ``django.utils.importlib`` is removed.

* ``django.utils.tzinfo`` is removed.

* ``django.utils.unittest`` is removed.

* The ``syncdb`` command is removed.

* ``django.db.models.signals.pre_syncdb`` and
  ``django.db.models.signals.post_syncdb`` is removed.

* Support for ``allow_syncdb`` on database routers is removed.

* The legacy method of syncing apps without migrations is removed,
  and migrations are compulsory for all apps. This includes automatic
  loading of ``initial_data`` fixtures and support for initial SQL data.

* All models need to be defined inside an installed application or declare an
  explicit :attr:`~django.db.models.Options.app_label`. Furthermore, it isn't
  possible to import them before their application is loaded. In particular, it
  isn't possible to import models inside the root package of an application.

* The model and form ``IPAddressField`` is removed. A stub field remains for
  compatibility with historical migrations.

* ``AppCommand.handle_app()`` is no longer be supported.

* ``RequestSite`` and ``get_current_site()`` are no longer importable from
  ``django.contrib.sites.models``.

* FastCGI support via the ``runfcgi`` management command is removed.

* ``django.utils.datastructures.SortedDict`` is removed.

* ``ModelAdmin.declared_fieldsets`` is removed.

* The ``util`` modules that provided backwards compatibility are removed:

  * ``django.contrib.admin.util``
  * ``django.contrib.gis.db.backends.util``
  * ``django.db.backends.util``
  * ``django.forms.util``

* ``ModelAdmin.get_formsets`` is removed.

* The backward compatible shims introduced to rename the
  ``BaseMemcachedCache._get_memcache_timeout()`` method to
  ``get_backend_timeout()`` is removed.

* The ``--natural`` and ``-n`` options for :djadmin:`dumpdata` are removed.

* The ``use_natural_keys`` argument for ``serializers.serialize()`` is removed.

* Private API ``django.forms.forms.get_declared_fields()`` is removed.

* The ability to use a ``SplitDateTimeWidget`` with ``DateTimeField`` is
  removed.

* The ``WSGIRequest.REQUEST`` property is removed.

* The class ``django.utils.datastructures.MergeDict`` is removed.

* The ``zh-cn`` and ``zh-tw`` language codes are removed.

* The internal ``django.utils.functional.memoize()`` is removed.

* ``django.core.cache.get_cache`` is removed.

* ``django.db.models.loading`` is removed.

* Passing callable arguments to querysets is no longer possible.

* ``BaseCommand.requires_model_validation`` is removed in favor of
  ``requires_system_checks``. Admin validators is replaced by admin checks.

* The ``ModelAdmin.validator_class`` and ``default_validator_class`` attributes
  are removed.

* ``ModelAdmin.validate()`` is removed.

* ``django.db.backends.DatabaseValidation.validate_field`` is removed in
  favor of the ``check_field`` method.

* The ``check`` management command is removed.

* ``django.utils.module_loading.import_by_path`` is removed in favor of
  ``django.utils.module_loading.import_string``.

* ``ssi`` and ``url`` template tags are removed from the ``future`` template
  tag library.

* ``django.utils.text.javascript_quote()`` is removed.

* Database test settings as independent entries in the database settings,
  prefixed by ``TEST_``, are no longer supported.

* The `cache_choices` option to :class:`~django.forms.ModelChoiceField` and
  :class:`~django.forms.ModelMultipleChoiceField` is removed.

* The default value of the
  :attr:`RedirectView.permanent <django.views.generic.base.RedirectView.permanent>`
  attribute has changed from ``True`` to ``False``.

* ``django.contrib.sitemaps.FlatPageSitemap`` is removed in favor of
  ``django.contrib.flatpages.sitemaps.FlatPageSitemap``.

* Private API ``django.test.utils.TestTemplateLoader`` is removed.

* The ``django.contrib.contenttypes.generic`` module is removed.
