=================================

Django version 0.96 release notes

=================================

Welcome to Django 0.96!

The primary goal for 0.96 is a cleanup and stabilization of the features

introduced in 0.95. There have been a few small `backwards-incompatible

changes`_ since 0.95, but the upgrade process should be fairly simple

and should not require major changes to existing applications.

However, we're also releasing 0.96 now because we have a set of

backwards-incompatible changes scheduled for the near future. Once

completed, they will involve some code changes for application

developers, so we recommend that you stick with Django 0.96 until the

next official release; then you'll be able to upgrade in one step

instead of needing to make incremental changes to keep up with the

development version of Django.

Backwards-incompatible changes

==============================

The following changes may require you to update your code when you switch from

0.95 to 0.96:

``MySQLdb`` version requirement

-------------------------------

Due to a bug in older versions of the ``MySQLdb`` Python module (which

Django uses to connect to MySQL databases), Django's MySQL backend now

requires version 1.2.1p2 or higher of ``MySQLdb``, and will raise

exceptions if you attempt to use an older version.

If you're currently unable to upgrade your copy of ``MySQLdb`` to meet

this requirement, a separate, backwards-compatible backend, called

"mysql_old", has been added to Django. To use this backend, change

the ``DATABASE_ENGINE`` setting in your Django settings file from this::

    DATABASE_ENGINE = "mysql"

to this::

    DATABASE_ENGINE = "mysql_old"

However, we strongly encourage MySQL users to upgrade to a more recent

version of ``MySQLdb`` as soon as possible, The "mysql_old" backend is

provided only to ease this transition, and is considered deprecated;

aside from any necessary security fixes, it will not be actively

maintained, and it will be removed in a future release of Django.

Also, note that some features, like the new ``DATABASE_OPTIONS``

setting (see the :doc:`databases documentation </ref/databases>` for details),

are only available on the "mysql" backend, and will not be made available for

"mysql_old".

Database constraint names changed

---------------------------------

The format of the constraint names Django generates for foreign key

references have changed slightly. These names are generally only used

when it is not possible to put the reference directly on the affected

column, so they are not always visible.

The effect of this change is that running ``manage.py reset`` and

similar commands against an existing database may generate SQL with

the new form of constraint name, while the database itself contains

constraints named in the old form; this will cause the database server

to raise an error message about modifying nonexistent constraints.

If you need to work around this, there are two methods available:

1. Redirect the output of ``manage.py`` to a file, and edit the

   generated SQL to use the correct constraint names before

   executing it.

2. Examine the output of ``manage.py sqlall`` to see the new-style

   constraint names, and use that as a guide to rename existing

   constraints in your database.

Name changes in ``manage.py``

-----------------------------

A few of the options to ``manage.py`` have changed with the addition of fixture

support:

* There are new ``dumpdata`` and ``loaddata`` commands which, as

  you might expect, will dump and load data to/from the

  database. These commands can operate against any of Django's

  supported serialization formats.

* The ``sqlinitialdata`` command has been renamed to ``sqlcustom`` to

  emphasize that ``loaddata`` should be used for data (and ``sqlcustom`` for

  other custom SQL -- views, stored procedures, etc.).

* The vestigial ``install`` command has been removed. Use ``syncdb``.

Backslash escaping changed

--------------------------

The Django database API now escapes backslashes given as query parameters. If

you have any database API code that matches backslashes, and it was working before

(despite the lack of escaping), you'll have to change your code to "unescape" the

slashes one level.

For example, this used to work::

    # Find text containing a single backslash

    MyModel.objects.filter(text__contains='\\\\')

The above is now incorrect, and should be rewritten as::

    # Find text containing a single backslash

    MyModel.objects.filter(text__contains='\\')

Removed ENABLE_PSYCO setting

----------------------------

The ``ENABLE_PSYCO`` setting no longer exists. If your settings file includes

``ENABLE_PSYCO`` it will have no effect; to use Psyco_, we recommend

writing a middleware class to activate it.

.. _psyco: http://psyco.sourceforge.net/

What's new in 0.96?

===================

This revision represents over a thousand source commits and over four hundred

bug fixes, so we can't possibly catalog all the changes. Here, we describe the

most notable changes in this release.

New forms library

-----------------

``django.newforms`` is Django's new form-handling library. It's a

replacement for ``django.forms``, the old form/manipulator/validation

framework.  Both APIs are available in 0.96, but over the next two

releases we plan to switch completely to the new forms system, and

deprecate and remove the old system.

There are three elements to this transition:

* We've copied the current ``django.forms`` to

  ``django.oldforms``. This allows you to upgrade your code *now*

  rather than waiting for the backwards-incompatible change and

  rushing to fix your code after the fact.  Just change your

  import statements like this::

      from django import forms             # 0.95-style

      from django import oldforms as forms # 0.96-style

* The next official release of Django will move the current

  ``django.newforms`` to ``django.forms``. This will be a

  backwards-incompatible change, and anyone still using the old

  version of ``django.forms`` at that time will need to change

  their import statements as described above.

* The next release after that will completely remove

  ``django.oldforms``.

Although the ``newforms`` library will continue to evolve, it's ready for use

for most common cases. We recommend that anyone new to form handling skip the

old forms system and start with the new.

For more information about ``django.newforms``, read the :doc:`newforms

documentation </topics/forms/index>`.

URLconf improvements

--------------------

You can now use any callable as the callback in URLconfs (previously, only

strings that referred to callables were allowed). This allows a much more

natural use of URLconfs. For example, this URLconf::

    from django.conf.urls.defaults import *

    urlpatterns = patterns('',

        ('^myview/$', 'mysite.myapp.views.myview')

    )

can now be rewritten as::

    from django.conf.urls.defaults import *

    from mysite.myapp.views import myview

    urlpatterns = patterns('',

        ('^myview/$', myview)

    )

One useful application of this can be seen when using decorators; this

change allows you to apply decorators to views *in your

URLconf*. Thus, you can make a generic view require login very

easily::

    from django.conf.urls.defaults import *

    from django.contrib.auth.decorators import login_required

    from django.views.generic.list_detail import object_list

    from mysite.myapp.models import MyModel

    info = {

        "queryset" : MyModel.objects.all(),

    }

    urlpatterns = patterns('',

        ('^myview/$', login_required(object_list), info)

    )

Note that both syntaxes (strings and callables) are valid, and will continue to

be valid for the foreseeable future.

The test framework

------------------

Django now includes a test framework so you can start transmuting fear into

boredom (with apologies to Kent Beck). You can write tests based on

:mod:`doctest` or :mod:`unittest` and test your views with a simple test client.

There is also new support for "fixtures" -- initial data, stored in any of the

supported :doc:`serialization formats </topics/serialization>`, that will be

loaded into your database at the start of your tests. This makes testing with

real data much easier.

See :doc:`the testing documentation </topics/testing/index>` for the full details.

Improvements to the admin interface

-----------------------------------

A small change, but a very nice one: dedicated views for adding and

updating users have been added to the admin interface, so you no

longer need to worry about working with hashed passwords in the admin.

Thanks

======

Since 0.95, a number of people have stepped forward and taken a major

new role in Django's development. We'd like to thank these people for

all their hard work:

* Russell Keith-Magee and Malcolm Tredinnick for their major code

  contributions. This release wouldn't have been possible without them.

* Our new release manager, James Bennett, for his work in getting out

  0.95.1, 0.96, and (hopefully) future release.

* Our ticket managers Chris Beaven (aka SmileyChris), Simon Greenhill,

  Michael Radziej, and Gary Wilson. They agreed to take on the monumental

  task of wrangling our tickets into nicely cataloged submission. Figuring

  out what to work on is now about a million times easier; thanks again,

  guys.

* Everyone who submitted a bug report, patch or ticket comment. We can't

  possibly thank everyone by name -- over 200 developers submitted patches

  that went into 0.96 -- but everyone who's contributed to Django is listed

  in :source:`AUTHORS`.