--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/parts/django/docs/releases/1.2.txt Sat Jan 08 11:20:57 2011 +0530
@@ -0,0 +1,1139 @@
+========================
+Django 1.2 release notes
+========================
+
+*May 17, 2010.*
+
+Welcome to Django 1.2!
+
+Nearly a year in the making, Django 1.2 packs an impressive list of `new
+features`_ and lots of bug fixes. These release notes cover the new features,
+as well as important changes you'll want to be aware of when upgrading from
+Django 1.1 or older versions.
+
+.. _new features: `What's new in Django 1.2`_
+
+Overview
+========
+
+Django 1.2 introduces several large, important new features, including:
+
+ * Support for `multiple database connections`_ in a single Django instance.
+
+ * `Model validation`_ inspired by Django's form validation.
+
+ * Vastly `improved protection against Cross-Site Request Forgery`_ (CSRF).
+
+ * A new `user "messages" framework`_ with support for cookie- and session-based
+ message for both anonymous and authenticated users.
+
+ * Hooks for `object-level permissions`_, `permissions for anonymous users`_,
+ and `more flexible username requirements`_.
+
+ * Customization of e-mail sending via `e-mail backends`_.
+
+ * New :ref:`"smart" if template tag <new-in-1.2-smart-if>` which supports
+ comparison operators.
+
+.. _multiple database connections: `support for multiple databases`_
+.. _improved protection against Cross-Site Request Forgery: `improved CSRF protection`_
+.. _user "messages" framework: `messages framework`_
+.. _more flexible username requirements: `relaxed requirements for usernames`_
+
+These are just the highlights; full details and a complete list of features `may
+be found below`_.
+
+.. _may be found below: `what's new in django 1.2`_
+
+.. seealso::
+
+ `Django Advent`_ covered the release of Django 1.2 with a series of
+ articles and tutorials that cover some of the new features in depth.
+
+.. _django advent: http://djangoadvent.com/
+
+Wherever possible these features have been introduced in a backwards-compatible
+manner per :doc:`our API stability policy </misc/api-stability>` policy.
+
+However, a handful of features *have* changed in ways that, for some users, will be
+backwards-incompatible. The big changes are:
+
+ * Support for Python 2.3 has been dropped. See the full notes
+ below.
+
+ * The new CSRF protection framework is not backwards-compatible with
+ the old system. Users of the old system will not be affected until
+ the old system is removed in Django 1.4.
+
+ However, upgrading to the new CSRF protection framework requires a few
+ important backwards-incompatible changes, detailed in `CSRF Protection`_,
+ below.
+
+ * Authors of custom :class:`~django.db.models.Field` subclasses should be
+ aware that a number of methods have had a change in prototype, detailed
+ under `get_db_prep_*() methods on Field`_, below.
+
+ * The internals of template tags have changed somewhat; authors of custom
+ template tags that need to store state (e.g. custom control flow tags)
+ should ensure that their code follows the new rules for `stateful template
+ tags`_
+
+ * The :func:`~django.contrib.auth.decorators.user_passes_test`,
+ :func:`~django.contrib.auth.decorators.login_required`, and
+ :func:`~django.contrib.auth.decorators.permission_required`, decorators
+ from :mod:`django.contrib.auth` only apply to functions and no longer
+ work on methods. There's a simple one-line fix `detailed below`_.
+
+.. _detailed below: `user_passes_test, login_required and permission_required`_
+
+Again, these are just the big features that will affect the most users. Users
+upgrading from previous versions of Django are heavily encouraged to consult
+the complete list of :ref:`backwards-incompatible changes
+<backwards-incompatible-changes-1.2>` and the list of :ref:`deprecated
+features <deprecated-features-1.2>`.
+
+Python compatibility
+====================
+
+While not a new feature, it's important to note that Django 1.2
+introduces the first shift in our Python compatibility policy since
+Django's initial public debut. Previous Django releases were tested
+and supported on 2.x Python versions from 2.3 up; Django 1.2, however,
+drops official support for Python 2.3. As such, the minimum Python
+version required for Django is now 2.4, and Django is tested and
+supported on Python 2.4, 2.5 and 2.6, and will be supported on the
+as-yet-unreleased Python 2.7.
+
+This change should affect only a small number of Django users, as most
+operating-system vendors today are shipping Python 2.4 or newer as
+their default version. If you're still using Python 2.3, however,
+you'll need to stick to Django 1.1 until you can upgrade; per
+:doc:`our support policy </internals/release-process>`, Django 1.1 will
+continue to receive security support until the release of Django 1.3.
+
+A roadmap for Django's overall 2.x Python support, and eventual
+transition to Python 3.x, is currently being developed, and will be
+announced prior to the release of Django 1.3.
+
+What's new in Django 1.2
+========================
+
+Support for multiple databases
+------------------------------
+
+Django 1.2 adds the ability to use :doc:`more than one database
+</topics/db/multi-db>` in your Django project. Queries can be issued at a
+specific database with the `using()` method on ``QuerySet`` objects. Individual
+objects can be saved to a specific database by providing a ``using`` argument
+when you call ``save()``.
+
+Model validation
+----------------
+
+Model instances now have support for :ref:`validating their own data
+<validating-objects>`, and both model and form fields now accept configurable
+lists of :doc:`validators </ref/validators>` specifying reusable, encapsulated
+validation behavior. Note, however, that validation must still be performed
+explicitly. Simply invoking a model instance's ``save()`` method will not
+perform any validation of the instance's data.
+
+Improved CSRF protection
+------------------------
+
+Django now has much improved protection against :doc:`Cross-Site Request Forgery
+(CSRF) attacks</ref/contrib/csrf>`. This type of attack occurs when a malicious
+Web site contains a link, a form button or some JavaScript that is intended to
+perform some action on your Web site, using the credentials of a logged-in user
+who visits the malicious site in their browser. A related type of attack, "login
+CSRF," where an attacking site tricks a user's browser into logging into a site
+with someone else's credentials, is also covered.
+
+Messages framework
+------------------
+
+Django now includes a robust and configurable :doc:`messages framework
+</ref/contrib/messages>` with built-in support for cookie- and session-based
+messaging, for both anonymous and authenticated clients. The messages framework
+replaces the deprecated user message API and allows you to temporarily store
+messages in one request and retrieve them for display in a subsequent request
+(usually the next one).
+
+Object-level permissions
+------------------------
+
+A foundation for specifying permissions at the per-object level has been added.
+Although there is no implementation of this in core, a custom authentication
+backend can provide this implementation and it will be used by
+:class:`django.contrib.auth.models.User`. See the :doc:`authentication docs
+</topics/auth>` for more information.
+
+Permissions for anonymous users
+-------------------------------
+
+If you provide a custom auth backend with ``supports_anonymous_user`` set to
+``True``, AnonymousUser will check the backend for permissions, just like
+User already did. This is useful for centralizing permission handling - apps
+can always delegate the question of whether something is allowed or not to
+the authorization/authentication backend. See the :doc:`authentication
+docs </topics/auth>` for more details.
+
+Relaxed requirements for usernames
+----------------------------------
+
+The built-in :class:`~django.contrib.auth.models.User` model's
+:attr:`~django.contrib.auth.models.User.username` field now allows a wider range
+of characters, including ``@``, ``+``, ``.`` and ``-`` characters.
+
+E-mail backends
+---------------
+
+You can now :ref:`configure the way that Django sends e-mail
+<topic-email-backends>`. Instead of using SMTP to send all e-mail, you
+can now choose a configurable e-mail backend to send messages. If your
+hosting provider uses a sandbox or some other non-SMTP technique for
+sending mail, you can now construct an e-mail backend that will allow
+Django's standard :doc:`mail sending methods</topics/email>` to use
+those facilities.
+
+This also makes it easier to debug mail sending. Django ships with
+backend implementations that allow you to send e-mail to a
+:ref:`file<topic-email-file-backend>`, to the
+:ref:`console<topic-email-console-backend>`, or to
+:ref:`memory<topic-email-memory-backend>`. You can even configure all
+e-mail to be :ref:`thrown away<topic-email-dummy-backend>`.
+
+.. _new-in-1.2-smart-if:
+
+"Smart" :ttag:`if` tag
+----------------------
+
+The :ttag:`if` tag has been upgraded to be much more powerful. First, we've
+added support for comparison operators. No longer will you have to type:
+
+.. code-block:: html+django
+
+ {% ifnotequal a b %}
+ ...
+ {% endifnotequal %}
+
+You can now do this:
+
+.. code-block:: html+django
+
+ {% if a != b %}
+ ...
+ {% endif %}
+
+There's really no reason to use ``{% ifequal %}`` or ``{% ifnotequal %}``
+anymore, unless you're the nostalgic type.
+
+The operators supported are ``==``, ``!=``, ``<``, ``>``, ``<=``, ``>=``,
+``in`` and ``not in``, all of which work like the Python operators, in addition
+to ``and``, ``or`` and ``not``, which were already supported.
+
+Also, filters may now be used in the ``if`` expression. For example:
+
+.. code-block:: html+django
+
+ <div
+ {% if user.email|lower == message.recipient|lower %}
+ class="highlight"
+ {% endif %}
+ >{{ message }}</div>
+
+Template caching
+----------------
+
+In previous versions of Django, every time you rendered a template, it
+would be reloaded from disk. In Django 1.2, you can use a :ref:`cached
+template loader <template-loaders>` to load templates once, then
+cache the result for every subsequent render. This can lead to a
+significant performance improvement if your templates are broken into
+lots of smaller subtemplates (using the ``{% extends %}`` or ``{%
+include %}`` tags).
+
+As a side effect, it is now much easier to support non-Django template
+languages. For more details, see the :ref:`notes on supporting
+non-Django template languages<topic-template-alternate-language>`.
+
+Natural keys in fixtures
+------------------------
+
+Fixtures can now refer to remote objects using
+:ref:`topics-serialization-natural-keys`. This lookup scheme is an
+alternative to the normal primary-key based object references in a
+fixture, improving readability and resolving problems referring to
+objects whose primary key value may not be predictable or known.
+
+Fast failure for tests
+----------------------
+
+Both the :djadmin:`test` subcommand of ``django-admin.py`` and the
+``runtests.py`` script used to run Django's own test suite now support a
+``--failfast`` option. When specified, this option causes the test runner to
+exit after encountering a failure instead of continuing with the test run. In
+addition, the handling of ``Ctrl-C`` during a test run has been improved to
+trigger a graceful exit from the test run that reports details of the tests that
+were run before the interruption.
+
+``BigIntegerField``
+-------------------
+
+Models can now use a 64-bit :class:`~django.db.models.BigIntegerField` type.
+
+Improved localization
+---------------------
+
+Django's :doc:`internationalization framework </topics/i18n/index>` has been expanded
+with locale-aware formatting and form processing. That means, if enabled, dates
+and numbers on templates will be displayed using the format specified for the
+current locale. Django will also use localized formats when parsing data in
+forms. See :ref:`Format localization <format-localization>` for more details.
+
+``readonly_fields`` in ``ModelAdmin``
+-------------------------------------
+
+:attr:`django.contrib.admin.ModelAdmin.readonly_fields` has been added to
+enable non-editable fields in add/change pages for models and inlines. Field
+and calculated values can be displayed alongside editable fields.
+
+Customizable syntax highlighting
+--------------------------------
+
+You can now use a ``DJANGO_COLORS`` environment variable to modify or disable
+the colors used by ``django-admin.py`` to provide :ref:`syntax highlighting
+<syntax-coloring>`.
+
+Syndication feeds as views
+--------------------------
+
+:doc:`Syndication feeds </ref/contrib/syndication>` can now be used directly as
+views in your :doc:`URLconf </topics/http/urls>`. This means that you can
+maintain complete control over the URL structure of your feeds. Like any other
+view, feeds views are passed a ``request`` object, so you can do anything you
+would normally do with a view, like user based access control, or making a feed
+a named URL.
+
+GeoDjango
+---------
+
+The most significant new feature for :doc:`GeoDjango </ref/contrib/gis/index>`
+in 1.2 is support for multiple spatial databases. As a result,
+the following :ref:`spatial database backends <spatial-backends>`
+are now included:
+
+* :mod:`django.contrib.gis.db.backends.postgis`
+* :mod:`django.contrib.gis.db.backends.mysql`
+* :mod:`django.contrib.gis.db.backends.oracle`
+* :mod:`django.contrib.gis.db.backends.spatialite`
+
+GeoDjango now supports the rich capabilities added
+in the `PostGIS 1.5 release <http://postgis.refractions.net/documentation/manual-1.5/>`_.
+New features include suppport for the the :ref:`geography type <geography-type>`
+and enabling of :ref:`distance queries <distance-queries>`
+with non-point geometries on geographic coordinate systems.
+
+Support for 3D geometry fields was added, and may be enabled
+by setting the :attr:`~django.contrib.gis.db.models.GeometryField.dim`
+keyword to 3 in your :class:`~django.contrib.gis.db.models.GeometryField`.
+The :class:`~django.contrib.gis.db.models.Extent3D` aggregate
+and :meth:`~django.contrib.gis.db.models.GeoQuerySet.extent3d` ``GeoQuerySet``
+method were added as a part of this feature.
+
+The following :class:`~django.contrib.gis.db.models.GeoQuerySet`
+methods are new in 1.2:
+
+* :meth:`~django.contrib.gis.db.models.GeoQuerySet.force_rhr`
+* :meth:`~django.contrib.gis.db.models.GeoQuerySet.reverse_geom`
+* :meth:`~django.contrib.gis.db.models.GeoQuerySet.geohash`
+
+The :ref:`GEOS interface <ref-geos>` was updated to use
+thread-safe C library functions when available on the platform.
+
+The :ref:`GDAL interface <ref-gdal>` now allows the user to
+set a :attr:`~django.contrib.gis.gdal.Layer.spatial_filter` on
+the features returned when iterating over a
+:class:`~django.contrib.gis.gdal.Layer`.
+
+Finally, :doc:`GeoDjango's documentation </ref/contrib/gis/index>` is now
+included with Django's and is no longer
+hosted separately at `geodjango.org <http://geodjango.org/>`_.
+
+.. _1.2-js-assisted-inlines:
+
+JavaScript-assisted handling of inline related objects in the admin
+-------------------------------------------------------------------
+
+If a user has JavaScript enabled in their browser, the interface for
+inline objects in the admin now allows inline objects to be
+dynamically added and removed. Users without JavaScript-enabled
+browsers will see no change in the behavior of inline objects.
+
+New ``now`` template tag format specifier characters: ``c`` and ``u``
+---------------------------------------------------------------------
+
+The argument to the :ttag:`now` has gained two new format characters:
+``c`` to specify that a datetime value should be formatted in ISO 8601
+format, and ``u`` that allows output of the microseconds part of a
+datetime or time value.
+
+These are also available in others parts like the :tfilter:`date` and
+:tfilter:`time` template filters, the ``humanize`` template tag library
+and the new `format localization`_ framework.
+
+.. _format localization: `Improved localization`_
+
+.. _backwards-incompatible-changes-1.2:
+
+Backwards-incompatible changes in 1.2
+=====================================
+
+Wherever possible the new features above have been introduced in a
+backwards-compatible manner per :doc:`our API stability policy
+</misc/api-stability>` policy. This means that practically all existing
+code which worked with Django 1.1 will continue to work with Django
+1.2; such code will, however, begin issuing warnings (see below for
+details).
+
+However, a handful of features *have* changed in ways that, for some
+users, will be immediately backwards-incompatible. Those changes are
+detailed below.
+
+CSRF Protection
+---------------
+
+We've made large changes to the way CSRF protection works, detailed in
+:doc:`the CSRF documentaton </ref/contrib/csrf>`. Here are the major changes you
+should be aware of:
+
+ * ``CsrfResponseMiddleware`` and ``CsrfMiddleware`` have been deprecated and
+ will be removed completely in Django 1.4, in favor of a template tag that
+ should be inserted into forms.
+
+ * All contrib apps use a ``csrf_protect`` decorator to protect the view. This
+ requires the use of the ``csrf_token`` template tag in the template. If you
+ have used custom templates for contrib views, you MUST READ THE :ref:`UPGRADE
+ INSTRUCTIONS <ref-csrf-upgrading-notes>` to fix those templates.
+
+ * ``CsrfViewMiddleware`` is included in :setting:`MIDDLEWARE_CLASSES` by
+ default. This turns on CSRF protection by default, so views that accept
+ POST requests need to be written to work with the middleware. Instructions
+ on how to do this are found in the CSRF docs.
+
+ * All of the CSRF has moved from contrib to core (with backwards
+ compatible imports in the old locations, which are deprecated and
+ will cease to be supported in Django 1.4).
+
+``get_db_prep_*()`` methods on ``Field``
+----------------------------------------
+
+Prior to Django 1.2, a custom ``Field`` had the option of defining
+several functions to support conversion of Python values into
+database-compatible values. A custom field might look something like::
+
+ class CustomModelField(models.Field):
+ # ...
+ def db_type(self):
+ # ...
+
+ def get_db_prep_save(self, value):
+ # ...
+
+ def get_db_prep_value(self, value):
+ # ...
+
+ def get_db_prep_lookup(self, lookup_type, value):
+ # ...
+
+In 1.2, these three methods have undergone a change in prototype, and
+two extra methods have been introduced::
+
+ class CustomModelField(models.Field):
+ # ...
+
+ def db_type(self, connection):
+ # ...
+
+ def get_prep_value(self, value):
+ # ...
+
+ def get_prep_lookup(self, lookup_type, value):
+ # ...
+
+ def get_db_prep_save(self, value, connection):
+ # ...
+
+ def get_db_prep_value(self, value, connection, prepared=False):
+ # ...
+
+ def get_db_prep_lookup(self, lookup_type, value, connection, prepared=False):
+ # ...
+
+These changes are required to support multiple databases --
+``db_type`` and ``get_db_prep_*`` can no longer make any assumptions
+regarding the database for which it is preparing. The ``connection``
+argument now provides the preparation methods with the specific
+connection for which the value is being prepared.
+
+The two new methods exist to differentiate general data-preparation
+requirements from requirements that are database-specific. The
+``prepared`` argument is used to indicate to the database-preparation
+methods whether generic value preparation has been performed. If
+an unprepared (i.e., ``prepared=False``) value is provided to the
+``get_db_prep_*()`` calls, they should invoke the corresponding
+``get_prep_*()`` calls to perform generic data preparation.
+
+We've provided conversion functions that will transparently
+convert functions adhering to the old prototype into functions
+compatible with the new prototype. However, these conversion functions
+will be removed in Django 1.4, so you should upgrade your ``Field``
+definitions to use the new prototype as soon as possible.
+
+If your ``get_db_prep_*()`` methods made no use of the database
+connection, you should be able to upgrade by renaming
+``get_db_prep_value()`` to ``get_prep_value()`` and
+``get_db_prep_lookup()`` to ``get_prep_lookup()``. If you require
+database specific conversions, then you will need to provide an
+implementation ``get_db_prep_*`` that uses the ``connection``
+argument to resolve database-specific values.
+
+Stateful template tags
+----------------------
+
+Template tags that store rendering state on their ``Node`` subclass
+have always been vulnerable to thread-safety and other issues; as of
+Django 1.2, however, they may also cause problems when used with the
+new :ref:`cached template loader<template-loaders>`.
+
+All of the built-in Django template tags are safe to use with the cached
+loader, but if you're using custom template tags that come from third
+party packages, or from your own code, you should ensure that the
+``Node`` implementation for each tag is thread-safe. For more
+information, see
+:ref:`template tag thread safety considerations<template_tag_thread_safety>`.
+
+You may also need to update your templates if you were relying on the
+implementation of Django's template tags *not* being thread safe. The
+:ttag:`cycle` tag is the most likely to be affected in this way,
+especially when used in conjunction with the :ttag:`include` tag.
+Consider the following template fragment::
+
+ {% for object in object_list %}
+ {% include "subtemplate.html" %}
+ {% endfor %}
+
+with a ``subtemplate.html`` that reads::
+
+ {% cycle 'even' 'odd' %}
+
+Using the non-thread-safe, pre-Django 1.2 renderer, this would output::
+
+ even odd even odd ...
+
+Using the thread-safe Django 1.2 renderer, you will instead get::
+
+ even even even even ...
+
+This is because each rendering of the :ttag:`include` tag is an
+independent rendering. When the :ttag:`cycle` tag was not thread safe,
+the state of the :ttag:`cycle` tag would leak between multiple
+renderings of the same :ttag:`include`. Now that the :ttag:`cycle` tag
+is thread safe, this leakage no longer occurs.
+
+``user_passes_test``, ``login_required`` and ``permission_required``
+--------------------------------------------------------------------
+
+``django.contrib.auth.decorators`` provides the decorators
+``login_required``, ``permission_required`` and
+``user_passes_test``. Previously it was possible to use these
+decorators both on functions (where the first argument is 'request')
+and on methods (where the first argument is 'self', and the second
+argument is 'request'). Unfortunately, flaws were discovered in the
+code supporting this: it only works in limited circumstances, and
+produces errors that are very difficult to debug when it does not
+work.
+
+For this reason, the 'auto adapt' behavior has been removed, and if
+you are using these decorators on methods, you will need to manually
+apply :func:`django.utils.decorators.method_decorator` to convert the
+decorator to one that works with methods. For example, you would
+change code from this::
+
+ class MyClass(object):
+
+ @login_required
+ def my_view(self, request):
+ pass
+
+to this::
+
+ from django.utils.decorators import method_decorator
+
+ class MyClass(object):
+
+ @method_decorator(login_required)
+ def my_view(self, request):
+ pass
+
+or::
+
+ from django.utils.decorators import method_decorator
+
+ login_required_m = method_decorator(login_required)
+
+ class MyClass(object):
+
+ @login_required_m
+ def my_view(self, request):
+ pass
+
+For those of you who've been following the development trunk, this
+change also applies to other decorators introduced since 1.1,
+including ``csrf_protect``, ``cache_control`` and anything created
+using ``decorator_from_middleware``.
+
+:ttag:`if` tag changes
+----------------------
+
+Due to new features in the :ttag:`if` template tag, it no longer
+accepts 'and', 'or' and 'not' as valid **variable** names. Previously,
+these strings could be used as variable names. Now, the keyword status
+is always enforced, and template code such as ``{% if not %}`` or ``{%
+if and %}`` will throw a ``TemplateSyntaxError``. Also, ``in`` is a
+new keyword and so is not a valid variable name in this tag.
+
+``LazyObject``
+--------------
+
+``LazyObject`` is an undocumented-but-often-used utility class used for lazily
+wrapping other objects of unknown type.
+
+In Django 1.1 and earlier, it handled introspection in a non-standard way,
+depending on wrapped objects implementing a public method named
+``get_all_members()``. Since this could easily lead to name clashes, it has been
+changed to use the standard Python introspection method, involving
+``__members__`` and ``__dir__()``.
+
+If you used ``LazyObject`` in your own code
+and implemented the ``get_all_members()`` method for wrapped objects, you'll need
+to make a couple of changes:
+
+First, if your class does not have special requirements for introspection (i.e.,
+you have not implemented ``__getattr__()`` or other methods that allow for
+attributes not discoverable by normal mechanisms), you can simply remove the
+``get_all_members()`` method. The default implementation on ``LazyObject`` will
+do the right thing.
+
+If you have more complex requirements for introspection, first rename the
+``get_all_members()`` method to ``__dir__()``. This is the standard
+introspection method for Python 2.6 and above. If you require support for Python
+versions earlier than 2.6, add the following code to the class::
+
+ __members__ = property(lambda self: self.__dir__())
+
+``__dict__`` on model instances
+-------------------------------
+
+Historically, the ``__dict__`` attribute of a model instance has only contained
+attributes corresponding to the fields on a model.
+
+In order to support multiple database configurations, Django 1.2 has
+added a ``_state`` attribute to object instances. This attribute will
+appear in ``__dict__`` for a model instance. If your code relies on
+iterating over ``__dict__`` to obtain a list of fields, you must now
+be prepared to handle or filter out the ``_state`` attribute.
+
+Test runner exit status code
+----------------------------
+
+The exit status code of the test runners (``tests/runtests.py`` and ``python
+manage.py test``) no longer represents the number of failed tests, because a
+failure of 256 or more tests resulted in a wrong exit status code. The exit
+status code for the test runner is now 0 for success (no failing tests) and 1
+for any number of test failures. If needed, the number of test failures can be
+found at the end of the test runner's output.
+
+Cookie encoding
+---------------
+
+To fix bugs with cookies in Internet Explorer, Safari, and possibly
+other browsers, our encoding of cookie values was changed so that the
+comma and semicolon are treated as non-safe characters, and are
+therefore encoded as ``\054`` and ``\073`` respectively. This could
+produce backwards incompatibilities, especially if you are storing
+comma or semi-colon in cookies and have javascript code that parses
+and manipulates cookie values client-side.
+
+``ModelForm.is_valid()`` and ``ModelForm.errors``
+-------------------------------------------------
+
+Much of the validation work for ModelForms has been moved down to the model
+level. As a result, the first time you call ``ModelForm.is_valid()``, access
+``ModelForm.errors`` or otherwise trigger form validation, your model will be
+cleaned in-place. This conversion used to happen when the model was saved. If
+you need an unmodified instance of your model, you should pass a copy to the
+``ModelForm`` constructor.
+
+``BooleanField`` on MySQL
+--------------------------
+
+In previous versions of Django, a model's ``BooleanField`` under MySQL
+would return its value as either ``1`` or ``0``, instead of ``True``
+or ``False``; for most people this wasn't a problem because ``bool``
+is a subclass of ``int`` in Python. In Django 1.2, however,
+``BooleanField`` on MySQL correctly returns a real ``bool``. The only
+time this should ever be an issue is if you were expecting the
+``repr`` of a ``BooleanField`` to print ``1`` or ``0``.
+
+Changes to the interpretation of ``max_num`` in FormSets
+--------------------------------------------------------
+
+As part of enhancements made to the handling of FormSets, the default
+value and interpretation of the ``max_num`` parameter to the
+:ref:`django.forms.formsets.formset_factory() <formsets-max-num>` and
+:ref:`django.forms.models.modelformset_factory()
+<model-formsets-max-num>` functions has changed slightly. This
+change also affects the way the ``max_num`` argument is :ref:`used for
+inline admin objects <ref-contrib-admin-inline-max-num>`
+
+Previously, the default value for ``max_num`` was ``0`` (zero).
+FormSets then used the boolean value of ``max_num`` to determine if a
+limit was to be imposed on the number of generated forms. The default
+value of ``0`` meant that there was no default limit on the number of
+forms in a FormSet.
+
+Starting with 1.2, the default value for ``max_num`` has been changed
+to ``None``, and FormSets will differentiate between a value of
+``None`` and a value of ``0``. A value of ``None`` indicates that no
+limit on the number of forms is to be imposed; a value of ``0``
+indicates that a maximum of 0 forms should be imposed. This doesn't
+necessarily mean that no forms will be displayed -- see the
+:ref:`ModelFormSet documentation <model-formsets-max-num>` for more
+details.
+
+If you were manually specifying a value of ``0`` for ``max_num``, you
+will need to update your FormSet and/or admin definitions.
+
+.. seealso::
+
+ :ref:`1.2-js-assisted-inlines`
+
+``email_re``
+------------
+
+An undocumented regular expression for validating email addresses has been moved
+from ``django.form.fields`` to ``django.core.validators``. You will need to
+update your imports if you are using it.
+
+.. _deprecated-features-1.2:
+
+Features deprecated in 1.2
+==========================
+
+Finally, Django 1.2 deprecates some features from earlier releases.
+These features are still supported, but will be gradually phased out
+over the next few release cycles.
+
+Code taking advantage of any of the features below will raise a
+``PendingDeprecationWarning`` in Django 1.2. This warning will be
+silent by default, but may be turned on using Python's `warnings
+module`_, or by running Python with a ``-Wd`` or `-Wall` flag.
+
+.. _warnings module: http://docs.python.org/library/warnings.html
+
+In Django 1.3, these warnings will become a ``DeprecationWarning``,
+which is *not* silent. In Django 1.4 support for these features will
+be removed entirely.
+
+.. seealso::
+
+ For more details, see the documentation :doc:`Django's release process
+ </internals/release-process>` and our :doc:`deprecation timeline
+ </internals/deprecation>`.`
+
+.. _specifying-databases:
+
+Specifying databases
+--------------------
+
+Prior to Django 1.2, Django used a number of settings to control
+access to a single database. Django 1.2 introduces support for
+multiple databases, and as a result the way you define database
+settings has changed.
+
+Any existing Django settings file will continue to work as expected
+until Django 1.4. Until then, old-style database settings will be
+automatically translated to the new-style format.
+
+In the old-style (pre 1.2) format, you had a number of ``DATABASE_``
+settings in your settings file. For example::
+
+ DATABASE_NAME = 'test_db'
+ DATABASE_ENGINE = 'postgresql_psycopg2'
+ DATABASE_USER = 'myusername'
+ DATABASE_PASSWORD = 's3krit'
+
+These settings are now in a dictionary named
+:setting:`DATABASES`. Each item in the dictionary corresponds to a
+single database connection, with the name ``'default'`` describing the
+default database connection. The setting names have also been
+shortened. The previous sample settings would now look like this::
+
+ DATABASES = {
+ 'default': {
+ 'NAME': 'test_db',
+ 'ENGINE': 'django.db.backends.postgresql_psycopg2',
+ 'USER': 'myusername',
+ 'PASSWORD': 's3krit',
+ }
+ }
+
+This affects the following settings:
+
+ ========================================= ==========================
+ Old setting New Setting
+ ========================================= ==========================
+ :setting:`DATABASE_ENGINE` :setting:`ENGINE`
+ :setting:`DATABASE_HOST` :setting:`HOST`
+ :setting:`DATABASE_NAME` :setting:`NAME`
+ :setting:`DATABASE_OPTIONS` :setting:`OPTIONS`
+ :setting:`DATABASE_PASSWORD` :setting:`PASSWORD`
+ :setting:`DATABASE_PORT` :setting:`PORT`
+ :setting:`DATABASE_USER` :setting:`USER`
+ :setting:`TEST_DATABASE_CHARSET` :setting:`TEST_CHARSET`
+ :setting:`TEST_DATABASE_COLLATION` :setting:`TEST_COLLATION`
+ :setting:`TEST_DATABASE_NAME` :setting:`TEST_NAME`
+ ========================================= ==========================
+
+These changes are also required if you have manually created a database
+connection using ``DatabaseWrapper()`` from your database backend of choice.
+
+In addition to the change in structure, Django 1.2 removes the special
+handling for the built-in database backends. All database backends
+must now be specified by a fully qualified module name (i.e.,
+``django.db.backends.postgresql_psycopg2``, rather than just
+``postgresql_psycopg2``).
+
+``postgresql`` database backend
+-------------------------------
+
+The ``psycopg1`` library has not been updated since October 2005. As a
+result, the ``postgresql`` database backend, which uses this library,
+has been deprecated.
+
+If you are currently using the ``postgresql`` backend, you should
+migrate to using the ``postgresql_psycopg2`` backend. To update your
+code, install the ``psycopg2`` library and change the
+:setting:`DATABASE_ENGINE` setting to use
+``django.db.backends.postgresql_psycopg2``.
+
+CSRF response-rewriting middleware
+----------------------------------
+
+``CsrfResponseMiddleware``, the middleware that automatically inserted
+CSRF tokens into ``POST`` forms in outgoing pages, has been deprecated
+in favor of a template tag method (see above), and will be removed
+completely in Django 1.4. ``CsrfMiddleware``, which includes the
+functionality of ``CsrfResponseMiddleware`` and
+``CsrfViewMiddleware``, has likewise been deprecated.
+
+Also, the CSRF module has moved from contrib to core, and the old
+imports are deprecated, as described in the :ref:`upgrading notes
+<ref-csrf-upgrading-notes>`.
+
+``SMTPConnection``
+------------------
+
+The ``SMTPConnection`` class has been deprecated in favor of a generic
+e-mail backend API. Old code that explicitly instantiated an instance
+of an SMTPConnection::
+
+ from django.core.mail import SMTPConnection
+ connection = SMTPConnection()
+ messages = get_notification_email()
+ connection.send_messages(messages)
+
+...should now call :meth:`~django.core.mail.get_connection()` to
+instantiate a generic e-mail connection::
+
+ from django.core.mail import get_connection
+ connection = get_connection()
+ messages = get_notification_email()
+ connection.send_messages(messages)
+
+Depending on the value of the :setting:`EMAIL_BACKEND` setting, this
+may not return an SMTP connection. If you explicitly require an SMTP
+connection with which to send e-mail, you can explicitly request an
+SMTP connection::
+
+ from django.core.mail import get_connection
+ connection = get_connection('django.core.mail.backends.smtp.EmailBackend')
+ messages = get_notification_email()
+ connection.send_messages(messages)
+
+If your call to construct an instance of ``SMTPConnection`` required
+additional arguments, those arguments can be passed to the
+:meth:`~django.core.mail.get_connection()` call::
+
+ connection = get_connection('django.core.mail.backends.smtp.EmailBackend', hostname='localhost', port=1234)
+
+User Messages API
+-----------------
+
+The API for storing messages in the user ``Message`` model (via
+``user.message_set.create``) is now deprecated and will be removed in Django
+1.4 according to the standard :doc:`release process </internals/release-process>`.
+
+To upgrade your code, you need to replace any instances of this::
+
+ user.message_set.create('a message')
+
+...with the following::
+
+ from django.contrib import messages
+ messages.add_message(request, messages.INFO, 'a message')
+
+Additionally, if you make use of the method, you need to replace the
+following::
+
+ for message in user.get_and_delete_messages():
+ ...
+
+...with::
+
+ from django.contrib import messages
+ for message in messages.get_messages(request):
+ ...
+
+For more information, see the full
+:doc:`messages documentation </ref/contrib/messages>`. You should begin to
+update your code to use the new API immediately.
+
+Date format helper functions
+----------------------------
+
+``django.utils.translation.get_date_formats()`` and
+``django.utils.translation.get_partial_date_formats()`` have been deprecated
+in favor of the appropriate calls to ``django.utils.formats.get_format()``,
+which is locale-aware when :setting:`USE_L10N` is set to ``True``, and falls
+back to default settings if set to ``False``.
+
+To get the different date formats, instead of writing this::
+
+ from django.utils.translation import get_date_formats
+ date_format, datetime_format, time_format = get_date_formats()
+
+...use::
+
+ from django.utils import formats
+ date_format = formats.get_format('DATE_FORMAT')
+ datetime_format = formats.get_format('DATETIME_FORMAT')
+ time_format = formats.get_format('TIME_FORMAT')
+
+Or, when directly formatting a date value::
+
+ from django.utils import formats
+ value_formatted = formats.date_format(value, 'DATETIME_FORMAT')
+
+The same applies to the globals found in ``django.forms.fields``:
+
+ * ``DEFAULT_DATE_INPUT_FORMATS``
+ * ``DEFAULT_TIME_INPUT_FORMATS``
+ * ``DEFAULT_DATETIME_INPUT_FORMATS``
+
+Use ``django.utils.formats.get_format()`` to get the appropriate formats.
+
+Function-based test runners
+---------------------------
+
+Django 1.2 changes the test runner tools to use a class-based
+approach. Old style function-based test runners will still work, but
+should be updated to use the new :ref:`class-based runners
+<topics-testing-test_runner>`.
+
+.. _1.2-updating-feeds:
+
+``Feed`` in ``django.contrib.syndication.feeds``
+------------------------------------------------
+
+The :class:`django.contrib.syndication.feeds.Feed` class has been
+replaced by the :class:`django.contrib.syndication.views.Feed` class.
+The old ``feeds.Feed`` class is deprecated, and will be removed in
+Django 1.4.
+
+The new class has an almost identical API, but allows instances to be
+used as views. For example, consider the use of the old framework in
+the following :doc:`URLconf </topics/http/urls>`::
+
+ from django.conf.urls.defaults import *
+ from myproject.feeds import LatestEntries, LatestEntriesByCategory
+
+ feeds = {
+ 'latest': LatestEntries,
+ 'categories': LatestEntriesByCategory,
+ }
+
+ urlpatterns = patterns('',
+ # ...
+ (r'^feeds/(?P<url>.*)/$', 'django.contrib.syndication.views.feed',
+ {'feed_dict': feeds}),
+ # ...
+ )
+
+Using the new Feed class, these feeds can be deployed directly as views::
+
+ from django.conf.urls.defaults import *
+ from myproject.feeds import LatestEntries, LatestEntriesByCategory
+
+ urlpatterns = patterns('',
+ # ...
+ (r'^feeds/latest/$', LatestEntries()),
+ (r'^feeds/categories/(?P<category_id>\d+)/$', LatestEntriesByCategory()),
+ # ...
+ )
+
+If you currently use the ``feed()`` view, the ``LatestEntries`` class would
+often not need to be modified apart from subclassing the new
+:class:`~django.contrib.syndication.views.Feed` class. The exception is if
+Django was automatically working out the name of the template to use to render
+the feed's description and title elements (if you were not specifying the
+``title_template`` and ``description_template`` attributes). You should ensure
+that you always specify ``title_template`` and ``description_template``
+attributes, or provide ``item_title()`` and ``item_description()`` methods.
+
+However, ``LatestEntriesByCategory`` uses the ``get_object()`` method
+with the ``bits`` argument to specify a specific category to show. In
+the new :class:`~django.contrib.syndication.views.Feed` class,
+``get_object()`` method takes a ``request`` and arguments from the
+URL, so it would look like this::
+
+ from django.contrib.syndication.views import Feed
+ from django.shortcuts import get_object_or_404
+ from myproject.models import Category
+
+ class LatestEntriesByCategory(Feed):
+ def get_object(self, request, category_id):
+ return get_object_or_404(Category, id=category_id)
+
+ # ...
+
+Additionally, the ``get_feed()`` method on ``Feed`` classes now take
+different arguments, which may impact you if you use the ``Feed``
+classes directly. Instead of just taking an optional ``url`` argument,
+it now takes two arguments: the object returned by its own
+``get_object()`` method, and the current ``request`` object.
+
+To take into account ``Feed`` classes not being initialized for each
+request, the ``__init__()`` method now takes no arguments by default.
+Previously it would have taken the ``slug`` from the URL and the
+``request`` object.
+
+In accordance with `RSS best practices`_, RSS feeds will now include
+an ``atom:link`` element. You may need to update your tests to take
+this into account.
+
+For more information, see the full :doc:`syndication framework
+documentation </ref/contrib/syndication>`.
+
+.. _RSS best practices: http://www.rssboard.org/rss-profile
+
+Technical message IDs
+---------------------
+
+Up to version 1.1 Django used :ref:`technical message IDs<technical-messages>`
+to provide localizers the possibility to translate date and time formats. They
+were translatable :term:`translation strings <translation string>` that could
+be recognized because they were all upper case (for example
+``DATETIME_FORMAT``, ``DATE_FORMAT``, ``TIME_FORMAT``). They have been
+deprecated in favor of the new :ref:`Format localization
+<format-localization>` infrastructure that allows localizers to specify that
+information in a ``formats.py`` file in the corresponding
+``django/conf/locale/<locale name>/`` directory.
+
+GeoDjango
+---------
+
+To allow support for multiple databases, the GeoDjango database internals were
+changed substantially. The largest backwards-incompatible change is that
+the module ``django.contrib.gis.db.backend`` was renamed to
+:mod:`django.contrib.gis.db.backends`, where the full-fledged
+:ref:`spatial database backends <spatial-backends>` now exist. The
+following sections provide information on the most-popular APIs that
+were affected by these changes.
+
+``SpatialBackend``
+^^^^^^^^^^^^^^^^^^
+
+Prior to the creation of the separate spatial backends, the
+``django.contrib.gis.db.backend.SpatialBackend`` object was
+provided as an abstraction to introspect on the capabilities of
+the spatial database. All of the attributes and routines provided by
+``SpatialBackend`` are now a part of the ``ops`` attribute of the
+database backend.
+
+The old module ``django.contrib.gis.db.backend`` is still provided
+for backwards-compatibility access to a ``SpatialBackend`` object,
+which is just an alias to the ``ops`` module of the
+*default* spatial database connection.
+
+Users that were relying on undocumented modules and objects
+within ``django.contrib.gis.db.backend``, rather the abstractions
+provided by ``SpatialBackend``, are required to modify their code.
+For example, the following import which would work in 1.1 and
+below::
+
+ from django.contrib.gis.db.backend.postgis import PostGISAdaptor
+
+Would need to be changed::
+
+ from django.db import connection
+ PostGISAdaptor = connection.ops.Adapter
+
+``SpatialRefSys`` and ``GeometryColumns`` models
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+In previous versions of GeoDjango, :mod:`django.contrib.gis.db.models`
+had ``SpatialRefSys`` and ``GeometryColumns`` models for querying
+the OGC spatial metadata tables ``spatial_ref_sys`` and ``geometry_columns``,
+respectively.
+
+While these aliases are still provided, they are only for the
+*default* database connection and exist only if the default connection
+is using a supported spatial database backend.
+
+.. note::
+
+ Because the table structure of the OGC spatial metadata tables
+ differs across spatial databases, the ``SpatialRefSys`` and
+ ``GeometryColumns`` models can no longer be associated with
+ the ``gis`` application name. Thus, no models will be returned
+ when using the ``get_models`` method in the following example::
+
+ >>> from django.db.models import get_app, get_models
+ >>> get_models(get_app('gis'))
+ []
+
+To get the correct ``SpatialRefSys`` and ``GeometryColumns``
+for your spatial database use the methods provided by the spatial backend::
+
+ >>> from django.db import connections
+ >>> SpatialRefSys = connections['my_spatialite'].ops.spatial_ref_sys()
+ >>> GeometryColumns = connections['my_postgis'].ops.geometry_columns()
+
+.. note::
+
+ When using the models returned from the ``spatial_ref_sys()`` and
+ ``geometry_columns()`` method, you'll still need to use the
+ correct database alias when querying on the non-default connection.
+ In other words, to ensure that the models in the example above
+ use the correct database::
+
+ sr_qs = SpatialRefSys.objects.using('my_spatialite').filter(...)
+ gc_qs = GeometryColumns.objects.using('my_postgis').filter(...)
+
+Language code ``no``
+--------------------
+
+The currently used language code for Norwegian Bokmål ``no`` is being
+replaced by the more common language code ``nb``.
+