# Django 2.1.8.dev20190330215650 documentation

# 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.

## 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 email sending via email backends.
- New "smart" if template tag which supports comparison operators.

These are just the highlights; full details and a complete list of features may be found below.

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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.

Wherever possible these features have been introduced in a backwards-compatible manner per our API stability policy 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 `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 `user_passes_test()`, `login_required()`, and `permission_required()`, decorators from `django.contrib.auth` only apply to functions and no longer work on methods. There's a simple one-line fix detailed below.

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 backwards-incompatible changes and the list of deprecated features.

## 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 our support policy, 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 more than one database 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 validating their own data, and both model and form fields now accept configurable lists of 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 Cross-Site Request Forgery (CSRF) attacks. This type of attack occurs when a malicious website contains a link, a form button or some JavaScript that is intended to perform some action on your website, 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 messages framework 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 `django.contrib.auth.models.User`. See the authentication docs 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 authentication docs for more details.

### Relaxed requirements for usernames

The built-in `User` model's `username` field now allows a wider range of characters, including `@`, `+`, `.` and `-` characters.

### Email backends

You can now configure the way that Django sends email. Instead of using SMTP to send all email, you can now choose a configurable email 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 email backend that will allow Django's standard mail sending methods to use those facilities.

This also makes it easier to debug mail sending. Django ships with backend implementations that allow you to send email to a file, to the console, or to memory. You can even configure all email to be thrown away.

### "Smart" `if` tag

The `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:

    {% ifnotequal a b %}
     ...
    {% endifnotequal %}

You can now do this:

    {% 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:

    <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 cached template loader 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.

### Class-based template loaders

As part of the changes made to introduce Template caching and following a general trend in Django, the template loaders API has been modified to use template loading mechanisms that are encapsulated in Python classes as opposed to functions, the only method available until Django 1.1.

All the template loaders shipped with Django have been ported to the new API but they still implement the function-based API and the template core machinery still accepts function-based loaders (builtin or third party) so there is no immediate need to modify your `TEMPLATE_LOADERS` setting in existing projects, things will keep working if you leave it untouched up to and including the Django 1.3 release.

If you have developed your own custom template loaders we suggest to consider porting them to a class-based implementation because the code for backwards compatibility with function-based loaders starts its deprecation process in Django 1.2 and will be removed in Django 1.4. There is a description of the API these loader classes must implement in the template API reference and you can also examine the source code of the loaders shipped with Django.

### Natural keys in fixtures

Fixtures can now refer to remote objects using 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 `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 `BigIntegerField` type.

### Improved localization

Django's internationalization framework 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 Format localization for more details.

### `readonly_fields` in `ModelAdmin`

`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 syntax highlighting.

### Syndication feeds as views

Syndication feeds can now be used directly as views in your URLconf. 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 GeoDjango in 1.2 is support for multiple spatial databases. As a result, the following spatial database backends are now included:

- `django.contrib.gis.db.backends.postgis`
- `django.contrib.gis.db.backends.mysql`
- `django.contrib.gis.db.backends.oracle`
- `django.contrib.gis.db.backends.spatialite`

GeoDjango now supports the rich capabilities added in the PostGIS 1.5 release. New features include support for the geography type and enabling of distance queries with non-point geometries on geographic coordinate systems.

Support for 3D geometry fields was added, and may be enabled by setting the `dim` keyword to 3 in your `GeometryField`. The `Extent3D` aggregate and `extent3d()` `GeoQuerySet` method were added as a part of this feature.

The `force_rhr()`, `reverse_geom()`, and `geohash()` `GeoQuerySet` methods are new.

The GEOS interface was updated to use thread-safe C library functions when available on the platform.

The GDAL interface now allows the user to set a `spatial_filter` on the features returned when iterating over a `Layer`.

Finally, GeoDjango's documentation is now included with Django's and is no longer hosted separately at geodjango.org.

### 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 `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 `date` and `time` template filters, the `humanize` template tag library and the new format localization framework.

## Backwards-incompatible changes in 1.2

Wherever possible the new features above have been introduced in a backwards-compatible manner per our API stability policy 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 the CSRF documentation. 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 UPGRADE INSTRUCTIONS to fix those templates.

  Documentation removed

  The upgrade notes have been removed in current Django docs. Please refer to the docs for Django 1.3 or older to find these instructions.

- `CsrfViewMiddleware` is included in `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 cached template loader.

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 template tag thread safety considerations.

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 `cycle` tag is the most likely to be affected in this way, especially when used in conjunction with the `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 `include` tag is an independent rendering. When the `cycle` tag was not thread safe, the state of the `cycle` tag would leak between multiple renderings of the same `include`. Now that the `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 `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`.

### `if` tag changes

Due to new features in the `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 django.forms.formsets.formset_factory() and django.forms.models.modelformset_factory() functions has changed slightly. This change also affects the way the `max_num` argument is used for inline admin objects.

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 ModelFormSet documentation 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.

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JavaScript-assisted handling of inline related objects in the admin

### `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.

## 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.

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.

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For more details, see the documentation Django's release process and our deprecation timeline.`

### 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 `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
--- | ---
DATABASE_ENGINE | `ENGINE`
DATABASE_HOST | `HOST`
DATABASE_NAME | `NAME`
DATABASE_OPTIONS | `OPTIONS`
DATABASE_PASSWORD | `PASSWORD`
DATABASE_PORT | `PORT`
DATABASE_USER | `USER`
TEST_DATABASE_CHARSET | `TEST_CHARSET`
TEST_DATABASE_COLLATION | `TEST_COLLATION`
TEST_DATABASE_NAME | `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 `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 upgrading notes.

Documentation removed

The upgrade notes have been removed in current Django docs. Please refer to the docs for Django 1.3 or older to find these instructions.

### `SMTPConnection`

The `SMTPConnection` class has been deprecated in favor of a generic email 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 `get_connection()` to instantiate a generic email 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 `EMAIL_BACKEND` setting, this may not return an SMTP connection. If you explicitly require an SMTP connection with which to send email, 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 `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 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 messages documentation. 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 `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 class-based runners.

### `Feed` in `django.contrib.syndication.feeds`

The `django.contrib.syndication.feeds.Feed` class has been replaced by the `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 URLconf:

    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 `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 `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 syndication framework documentation.

### Technical message IDs

Up to version 1.1 Django used technical message IDs to provide localizers the possibility to translate date and time formats. They were translatable translation strings 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 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 `django.contrib.gis.db.backends`, where the full-fledged spatial database 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, `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.

주석

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()

주석

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`.

### Function-based template loaders

Django 1.2 changes the template loading mechanism to use a class-based approach. Old style function-based template loaders will still work, but should be updated to use the new class-based template loaders.