Updated API stability document for 1.0.

.. _path file: http://docs.python.org/lib/module-site.html

.. _official-releases:

Official releases

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

API stability

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

Although Django has not reached a 1.0 release, the bulk of Django's public APIs are

stable as of the 0.95 release. This document explains which APIs will and will not

change before the 1.0 release.

:ref:`The release of Django 1.0 <releases-1.0>` comes with a promise of API

stability and forwards-compatibility. In a nutshell, this means that code you

develop against Django 1.0 will continue to work against 1.1 unchanged, and you

should need to make only minor changes for any 1.X release.

What "stable" means

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

In this context, stable means:

   - All the public APIs -- everything documented in the linked documents, and

     all methods that don't begin with an underscore -- will not be moved or

   - All the public APIs -- everything documented in the linked documents below,

     and all methods that don't begin with an underscore -- will not be moved or

     renamed without providing backwards-compatible aliases.

   - If new features are added to these APIs -- which is quite possible --

     words, "stable" does not (necessarily) mean "complete."

   - If, for some reason, an API declared stable must be removed or replaced, it

     will be declared deprecated but will remain in the API until at least

     version 1.1. Warnings will be issued when the deprecated method is

     called.

     will be declared deprecated but will remain in the API for at least two

     minor version releases. Warnings will be issued when the deprecated method

     is called.

     See :ref:`official-releases` for more details on how Django's version

     numbering scheme works, and how features will be deprecated.

   - We'll only break backwards compatibility of these APIs if a bug or

     security hole makes it completely unavoidable.

Stable APIs

===========

These APIs are stable:

In general, everything covered in the documentation -- with the exception of

anything in the :ref:`internals area <internals-index>` is considered stable as

of 1.0. This includes these APIs:

    - :ref:`Authorization <topics-auth>`

    - :ref:`Caching <topics-cache>`.

   - :ref:`Custom template tags and libraries <howto-custom-template-tags>`.

    - :ref:`Model definition, managers, querying and transactions

      <topics-db-index>`

   - :ref:`Database lookup <topics-db-queries>` (with the exception of validation; see below).

    - :ref:`Sending e-mail <topics-email>`.

   - :ref:`django-admin utility <ref-django-admin>`.

    - :ref:`File handling and storage <topics-files>`

   - :ref:`FastCGI and mod_python integration <howto-deployment-index>`.

    - :ref:`Forms <topics-forms-index>`

   - :ref:`Flatpages <ref-contrib-flatpages>`.

    - :ref:`HTTP request/response handling <topics-http-index>`, including file

      uploads, middleware, sessions, URL resolution, view, and shortcut APIs.

    - :ref:`Generic views <topics-http-generic-views>`.

    - :ref:`Internationalization <topics-i18n>`.

   - :ref:`Legacy database integration <howto-legacy-databases>`.

    - :ref:`Pagination <topics-pagination>`

    - :ref:`Serialization <topics-serialization>`

   - :ref:`Model definition <topics-db-models>` (with the exception of generic relations; see below).

    - :ref:`Signals <topics-signals>`

    - :ref:`Templates <topics-templates>`, including the language, Python-level

      :ref:`template APIs <ref-templates-index>`, and :ref:`custom template tags

      and libraries <howto-custom-template-tags>`.

    - :ref:`Testing <topics-testing>`

    - :ref:`django-admin utility <ref-django-admin>`.

   - :ref:`Redirects <ref-contrib-redirects>`.

    - :ref:`Built-in middleware <ref-middleware>`

    - :ref:`Request/response objects <ref-request-response>`.

   - :ref:`Sending e-mail <topics-email>`.

    - :ref:`Settings <ref-settings>`. Note, though that while the :ref:`list of

      built-in settings <ref-settings>` can be considered complete we may -- and

      probably will -- add new settings in future versions. This is one of those

      places where "'stable' does not mean 'complete.'"

    - :ref:`Built-in signals <ref-signals>`. Like settings, we'll probably add

      new signals in the future, but the existing ones won't break.

    - :ref:`Unicode handling <ref-unicode>`.

    - Everything covered by the :ref:`HOWTO guides <howto-index>`.

``django.utils``

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

Most of the modules in ``django.utils`` are designed for internal use. Only the following parts of ``django.utils`` can be considered stable:

    - ``django.utils.cache``

    - ``django.utils.datastructures.SortedDict`` -- only this single class; the

      rest of the module is for internal use.

    - ``django.utils.encoding``

    - ``django.utils.feedgenerator``

    - ``django.utils.safestring``

    - ``django.utils.tzinfo``

    - ``django.utils.encoding``

Exceptions

==========

   - :ref:`Sessions <topics-http-sessions>`.

There are a few exceptions to this stability and backwards-compatibility

promise.

   - :ref:`Settings <topics-settings>`.

Security fixes

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

   - :ref:`Syndication <ref-contrib-syndication>`.

If we become aware of a security problem -- hopefully by someone following our

:ref:`security reporting policy <reporting-security-issues>` -- we'll do

everything necessary to fix it. This might mean breaking backwards compatibility; security trumps the compatibility guarantee.

   - :ref:`Template language <topics-templates>` (with the exception of some

     possible disambiguation of how tag arguments are passed to tags and

     filters).

Contributed applications (``django.contrib``)

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

   - :ref:`Transactions <topics-db-transactions>`.

While we'll make every effort to keep these APIs stable -- and have no plans to

break any contrib apps -- this is an area that will have more flux between

releases. As the web evolves, Django must evolve with it.

   - :ref:`URL dispatch <topics-http-urls>`.

However, any changes to contrib apps will come with an important guarantee:

we'll make sure it's always possible to use an older version of a contrib app if

we need to make changes. Thus, if Django 1.5 ships with a backwards-incompatible

``django.contrib.flatpages``, we'll make sure you can still use the Django 1.4

version alongside Django 1.5. This will continue to allow for easy upgrades.

You'll notice that this list comprises the bulk of Django's APIs. That's right

-- most of the changes planned between now and Django 1.0 are either under the

hood, feature additions, or changes to a few select bits. A good estimate is

that 90% of Django can be considered forwards-compatible at this point.

Historically, apps in ``django.contrib`` have been more stable than the core, so

in practice we probably won't have to ever make this exception. However, it's

worth noting if you're building apps that depend on ``django.contrib``.

That said, these APIs should *not* be considered stable, and are likely to

change:

APIs marked as internal

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

   - :ref:`Serialization <topics-serialization>` is under development; changes

     are possible.

Certain APIs are explicitly marked as "internal" in a couple of ways:

   - Generic relations will most likely be moved out of core and into the

     content-types contrib package to avoid core dependencies on optional

     components.

    - Some documentation refers to internals and mentions them as such. If the

      documentation says that something is internal, we reserve the right to

      change it.

     **New in development version**: this has now been done.

    - Functions, methods, and other objects prefixed by a leading underscore

      (``_``). This is the standard Python way of indicating that something is

      private; if any method starts with a single ``_``, it's an internal API.

   - The comments framework, which is yet undocumented, will get a complete

     rewrite before Django 1.0.

Welcome to Django 1.0!

Stability and forwards-compatibility

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

:ref:`The release of Django 1.0 <releases-1.0>` comes with a promise of API

stability and forwards-compatibility. In a nutshell, this means that code you

develop against Django 1.0 will continue to work against 1.1 unchanged, and you

should need to make only minor changes for any 1.X release.

See the :ref:`API stability guide <misc-api-stability>` for full details.

Porting guide

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

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

You can find detailed instructions on porting apps from Django 0.96 to Django

1.0 in our porting guide: