
.. _0-7-release-notes:

=========
South 0.7
=========

This is a major new release of South. A lot of work has been done to the
internals, and a few annoying remnants from South's history have
finally been eradicated.


Backwards incompatible changes
==============================

Tests now run with migrations by default, not using syncdb for everything as in
0.6. This is the behaviour most people expect; to turn it off again,
set ``SOUTH_TESTS_MIGRATE`` to False (migrating everything can be slow).

In addition, you may note that some or all of your custom fields don't work when
you upgrade; read more about this at :ref:`custom-fields`. You may also wish to
change your old migration files and insert the full path to custom field classes
in the ``models`` dictionary entries, to prevent future issues.


Major changes
=============

Core Refactoring
----------------

The entire migration and dependency engine has been refactored to be
class-based, rather than the mess of functions and variables it was before,
and will now be a lot easier to maintain, as well as being nice and quick.

Much thanks to Simon Law for doing a lot of the legwork on this one.

Command Changes
---------------
 
The ``startmigration`` command (which used to be one massive file) has been
removed, and refactored into new commands:

 - ``schemamigration``, which is very similar to the old ``startmigration``
 - ``datamigration``, which should be used to create new data migrations

In addition, the ``--model`` argument to ``startmigration`` is now
``--add-model`` on ``schemamigration``, for consistency with the other
arguments, and ``schemamigration`` no longer requires a migration name; if you
don't provide one, it will autogenerate a reasonably sensible one.

Finally, South now detects when you're adding a column that needs a default
value, and prompts you for it, rather than crashing when you tried to apply
the migration, like before.

Django Support
--------------

This version of South fully supports Django 1.2 (as well as 1.1 and 1.0),
and has some limited multi-db functionality (migrate has gained a --database
option) [#]_.

.. [#] Note that multi-db functionality is unavailable if using South 0.7 with
       earlier versions of Django.

Custom Fields
-------------

Custom fields are no longer parsed if they don't introspect; instead, an
error is raised every time. This is because parsing was causing scenarios where
migrations sometimes worked, and then failed mysteriously later; the new
solution means they'll always work or fail.

This does have the unfortunate side-effect of making South not "magically" make
your simpler custom fields work any more; we're trying to help by shipping
introspection modules for the more common third-party apps with South, but you
may also want to read the new 
:ref:`reference for your own introspection rules <extending-introspection>`, or
:ref:`our new tutorial chapter on it <tutorial-part-4>`.

Migration Directories
---------------------

You can now set custom migration directories (actually done as Python modules)
if you need per-project migrations for an app, or if you are using third-party
apps and don't want to store the migrations with the app.

You simply need to set the new :ref:`setting-south-migration-modules` setting.

Supported Databases
-------------------

SQLite now has full, near-bulletproof support for altering columns,
deleting columns, and other basic operations SQLite doesn't support natively.

Oracle now has alpha support.

Migrations Files
----------------

Migrations files no longer import from appname.models; model classes are now
referred to by their full path, and retrieved using ``Migration.gf`` - this
means a field now looks like::

 self.gf('django.db.models.fields.TextField')(blank=True)

Also, migration classes should now inherit from ``south.v2.SchemaMigration`` or
``south.v2.DataMigration``. This doesn't do much at the moment, but is designed
so we can easily change the migration API in future and keep backwards
compatability.

Bugfixes and minor changes
--------------------------

There's also an assorted array of bugfixes; see the `milestone status page
<http://south.aeracode.org/query?status=accepted&status=assigned&status=closed&status=new&status=reopened&group=status&order=priority&milestone=0.7>`_ for details.

Thanks
======

This release wouldn't have been possible without:

 - Simon Law, who wrote most of the migration refactor and now knows too much about how our dependencies work
 - `Torchbox <http://www.torchbox.com>`_, who sponsored Andrew's work on the startmigration refactor, the rest of the migration refactor, and a lot of other small things.
 - Ilya Roitburg, who contributed the Oracle database module.
 