# Django 4.1.8.dev20230308103347 ドキュメント

# Django 1.9 リリースノート

December 1, 2015

Django 1.9 へようこそ！

このリリースノートでは、 バージョン 1.9 の新機能 と、Django 1.8 以前からアップグレードする際に注意が必要な 後方互換性が失われた変更点 について説明します。私たちは、非推奨の期間が終了した いくつかの機能の廃止 を行い、さらに いくつかの機能に対する新しい非推奨期間 を開始しました。

既存のプロジェクトをアップデートするときは、 How to upgrade Django to a newer version ガイドに従ってください。

## Python バージョン間の互換性

Django 1.9 の動作には Python 2.7, 3.4, 3.5 のいずれかが必要です。各バージョン系列の最終リリースの Python を使用することを 強く推奨 し、公式には最終リリースしかサポートしません。

Django 1.8 シリーズが Python 3.2 および 3.3 をサポートする最後のバージョンになります。

## Django 1.9 で新しくなったこと

### トランザクションのコミット後にアクションを実行する機能

新しく追加された `on_commit()` フックを使えば、データベースのトランザクションが成功した時点で好きなアクションが実行できます。この機能は、メール通知を送信したり、新しいタスクキューを作成したり、キャッシュを無効化するのに便利です。

この機能は django-transaction-hooks パッケージから Django に取り入れられたものです。

### パスワードの妥当性検証

Django は新しくパスワード検証機能を提供します。これによりユーザーが弱いパスワードを使用するのを防けるようになります。検証機能は同梱のパスワードの変更・リセットフォームに統合されているので、他のコードと組み合わせるのも簡単です。検証は1つ以上の検証器 (validator) で実行され、新しい `AUTH_PASSWORD_VALIDATORS` 設定でカスタマイズすることができます。

Django には4つの検証器が組み込まれています。それぞれ、パスワードの最小長の強制、名前などのユーザーの属性とパスワードとの比較、数字のみのパスワードでないかの確認、よく使われるパスワードのリストに含まれていないかのチェックを実行します。複数の検証器を組み合わせることが可能で、設定オプションをカスタマイズできる検証器もあります。たとえば、よくあるパスワードのリストとして自前のリストを渡すことができます。各検証器は、ユーザーに対して必要な条件を説明するヘルプテキストを返します。

デフォルトでは、検証は実行されずにすべてのパスワードが許可されます。そのため、 `AUTH_PASSWORD_VALIDATORS` を設定しなければ、何も変更する必要はありません。デフォルトの `startproject` テンプレートを使用して新しいプロジェクトを作成すると、基本的な検証機が有効になります。既存のプロジェクトの認証フォームで基本的な検証を有効にするには、たとえば次のように設定します。

    AUTH_PASSWORD_VALIDATORS = [
        {
            'NAME': 'django.contrib.auth.password_validation.UserAttributeSimilarityValidator',
        },
        {
            'NAME': 'django.contrib.auth.password_validation.MinimumLengthValidator',
        },
        {
            'NAME': 'django.contrib.auth.password_validation.CommonPasswordValidator',
        },
        {
            'NAME': 'django.contrib.auth.password_validation.NumericPasswordValidator',
        },
    ]

詳しくは パスワードの妥当性検証 を読んでください。

### クラスベースのビューに対するミックスインの許可

Django は新しく次のミックスインを同梱するようになりました。 `AccessMixin`, `LoginRequiredMixin`, `PermissionRequiredMixin`, そして `UserPassesTestMixin` です。これらを使えば、クラスベースのビューに対して、 `django.contrib.auth.decorators` の機能を使用できるようになります。これらのミックスインは django-braces プロジェクトにインスパイアされて実装されました。

ただし、Django と `django-braces` の実装には次のような相違点があります。

- `raise_exception` 属性は `True` または `False` のいずれかのみであり、カスタムの例外や callable はサポートしない。
- `handle_no_permission()` メソッドは `request` 引数を取らない。現在の request は `self.request` でアクセス可能である。
- `UserPassesTestMixin` のカスタムの `test_func()` は `user` 引数を取らない。現在のユーザーは `self.request.user` でアクセス可能である。
- `permission_required` 属性は文字列 (1つのパーミッションを定義する) または文字列のリストかタプル (複数のパーミッションを定義する) をサポートする。この属性はアクセス権限を得るために必要である。
- 新しい `permission_denied_message` 属性を使えば、 `PermissionDenied` 例外にメッセージを送ることができる。

### `contrib.admin` への新しいスタイルの導入

admin は新たにモダンなフラットデザインをまといました。これには HiDPI スクリーンでも美しく表示できる SVG アイコンも含まれます。YUI's A-grade ブラウザの完全な機能体験を提供します。古いブラウザによっては、一部の機能体験のレベルが下がることがあります。

### テストの並列実行

`test` コマンドは新たに、プロジェクトのテストをマルチプロセスで実行する `--parallel` オプションをサポートします。

各プロセスごとに個別のデータベースを持つため、異なるテストケースが同じリソースにアクセスしないように注意が必要です。たとえば、複数のテストケースがファイルシステムにアクセスするような場合には、各テストケースごとに個別に一時ディレクトリを作成するようにしてください。

このオプションは、Django 自身のテストスイートでは、以下の条件下で有効になります。

- Windows を除く全ての OS
- Oracle 以外のすべてのデータベースバックエンド

### マイナーな機能

#### `django.contrib.admin`

- admin ビューは新たに `model_admin` または `admin_site` 属性を持ちます。
- admin change ビューの URL が変更されました (デフォルトで `/admin/<app>/<model>/<pk>/` にありましたが、新しく `/admin/<app>/<model>/<pk>/change/` に変わりました)。admin の URL をハードコードしていない限り、既存のアプリケーションで問題は起こらないはずです。ハードコードしてしまっていた場合、リンクの代わりに admin URL の逆リンク を使用してください。後方互換性を確保するために、古い URL は新しい URL にリダイレクトされていますが、将来のバージョンではリダイレクトは削除される予定なので気をつけてください。
- `ModelAdmin.get_list_select_related()` が追加され、 admin changelist クエリで使われていた `select_related()` の値をリクエストに基づいて変更できるようになりました。
- 現在のユーザーが使用可能なアプリケーションのリストを値として持つ `available_apps` コンテキスト変数が、新たに `AdminSite.each_context()` メソッドに追加されました。
- `AdminSite.empty_value_display` および `ModelAdmin.empty_value_display` が追加され、admin change list の中の空の値の表示を上書きすることができるようになりました。また、各フィールドの値をカスタマイズすることもできます。
- change form ページに inline form の追加または削除時 に発生する jQuery イベントが追加されました。
- The time picker widget includes a '6 p.m' option for consistency of having predefined options every 6 hours.
- JavaScript slug 生成機能が、新しくルーマニア語の文字をサポートするようになりました。

#### `django.contrib.admindocs`

- The model section of the `admindocs` now also describes methods that take arguments, rather than ignoring them.

#### `django.contrib.auth`

- The default iteration count for the PBKDF2 password hasher has been increased by 20%. This backwards compatible change will not affect users who have subclassed `django.contrib.auth.hashers.PBKDF2PasswordHasher` to change the default value.
- The `BCryptSHA256PasswordHasher` will now update passwords if its `rounds` attribute is changed.
- `AbstractBaseUser` and `BaseUserManager` were moved to a new `django.contrib.auth.base_user` module so that they can be imported without including `django.contrib.auth` in `INSTALLED_APPS` (doing so raised a deprecation warning in older versions and is no longer supported in Django 1.9).
- The permission argument of `permission_required()` accepts all kinds of iterables, not only list and tuples.
- The new `PersistentRemoteUserMiddleware` makes it possible to use `REMOTE_USER` for setups where the header is only populated on login pages instead of every request in the session.
- The `django.contrib.auth.views.password_reset()` view accepts an `extra_email_context` parameter.

#### `django.contrib.contenttypes`

- `order_with_respect_to` が `GenericForeignKey` とともに使用できるようになりました。

#### `django.contrib.gis`

- すべての `GeoQuerySet` メソッドが廃止され、 等価なデータベース関数 で置き換えられました。コードで使用している古いメソッドを置き換えるとともに、GIS が有効なクラスから特別な `GeoManager` を削除しなければなりません。
- GDAL インターフェイスが、raw データからファイルベースでインメモリの GDALRaster オブジェクト のインスタンス化をサポートしました。projection や pixel の値などのラスター属性の setter が追加されました。
- PostGIS のユーザは、 `RasterField` により GDALRaster オブジェクトの保存 ができるようになりました。このクラスはモデル保存時の自動的な spatial index の作成や reprojection をサポートします。spatial querying はまだサポートしていません。
- The new `GDALRaster.warp()` method allows warping a raster by specifying target raster properties such as origin, width, height, or pixel size (among others).
- The new `GDALRaster.transform()` method allows transforming a raster into a different spatial reference system by specifying a target `srid`.
- 新しい `GeoIP2` クラスが、IPv6 アドレスをサポートする MaxMind の GeoLite2 データベースを扱えるようになりました。
- ウィジェットに含まれるデフォルトの OpenLayers ライブラリのバージョンが 2.13 から 2.13.1 にアップデートされました。

#### `django.contrib.postgres`

- range フィールドに対応するいくつかのビルトインのフィールドに対する `rangefield.contained_by` lookup のサポートが追加されました。
- Added `django.contrib.postgres.fields.JSONField`.
- PostgreSQL specific aggregation functions が追加されました。
- `TransactionNow` データベース関数が追加されました。

#### `django.contrib.sessions`

- The session model and `SessionStore` classes for the `db` and `cached_db` backends are refactored to allow a custom database session backend to build upon them. See データベースを使ったセッションを拡張する for more details.

#### `django.contrib.sites`

- `get_current_site()` が新たに `request.get_host()` が `domain:port` という形式 (例: `example.com:80`) の値を返す場合でもハンドリングできるようになりました。host がデータベースレコードとマッチせず、host が port を持っているせいで lookup が失敗する場合、ドメイン部分だけを使用して lookup を再試行します。

#### `django.contrib.syndication`

- 各フィードアイテムごとの複数の enclosure のサポートが追加されました。Atom フィードとは違い、RSS はフィードアイテムごとの複数の enclosure をサポートしないため、RSS フィードで使用すると例外が発生します。

#### キャッシュ

- 新しく `django.core.cache.backends.base.BaseCache` が `get_or_set()` メソッドを持つようになりました。
- キャッシュされることををより確実に防ぐため、 `django.views.decorators.cache.never_cache()` がより積極的にヘッダを追加するようになりました (`no-cache, no-store, must-revalidate` が `Cache-Control` に追加されます)。この関数は Django 1.8.8 で追加されました。

#### CSRF

- CSRF 認証に使われる request ヘッダの名前が `CSRF_HEADER_NAME` で設定できるようになりました。
- `CSRF_COOKIE_DOMAIN` 設定が設定されているかどうかにかかわらず、CSRF referer ヘッダが検証されるようになりました。詳しくは How it works を見てください。
- The new `CSRF_TRUSTED_ORIGINS` setting provides a way to allow cross-origin unsafe requests (e.g. `POST`) over HTTPS.

#### データベースバックエンド

- PostgreSQL バックエンド (`django.db.backends.postgresql_psycopg2`) が `django.db.backends.postgresql` から使用できるようになりました。後方互換性を確保するため、古い名前もそのまま使用できます。

#### ファイルストレージ

- `upload_to` が callable の場合に `Storage.get_valid_name()` が呼ばれるようになりました。
- Python 3 を使用している場合に `File` が `seekable()` メソッドを使えるようになりました。

#### フォーム

- `ModelForm` が新しい `Meta` オプションとして `field_classes` を使えるようになりました。これにより、フィールドの種類をカスタマイズできるようになります。詳しくは デフォルトのフィールドをオーバライドする を読んでください。
- `field_order` 属性、 `field_order` コンストラクタの引数、 `order_fields()` メソッドのいずれかを使用して、form のフィールドをレンダリングする順番を指定できるようになりました。
- form prefix が、form のインスタンス化の時だけでなく form クラスの内部でも指定できるようになりました。詳しくは Prefixes for forms を読んでください。
- formset 内の form のコンストラクタに渡したい キーワード引数を指定する ことができるようになりました。
- `SlugField` で `allow_unicode` 引数を使うことで、Unicode 文字を slug 内で使用できるようになりました。
- `CharField` が `strip` 引数を取れるようになり、前後のホワイトスペースを取り除けるようになりました。この値はデフォルトで `True` なので、過去のリリースと異なる動作をすることになります。
- Form フィールドが `disabled` 引数をサポートするようになり、ブラウザで disabled の状態でウィジェットを表示できるようになりました。
- フィールドの `get_bound_field()` メソッドをオーバーライドすることで、フィールドの境界線をカスタマイズすることができるようになりました。

#### ジェネリックビュー (generic view)

- `as_view()` メソッドで生成されたクラスベースのビューに `view_class` と `view_initkwargs` 属性が追加されました。
- `method_decorator()` がデコレータのタプルまたはリストで呼び出せるようになりました。 メソッドの代わりにデコレートしたクラス に使用することもできます。

#### 国際化 (internationalization)

- 利用可能な場合、`django.views.i18n.set_language()` ビューが、適切な 翻訳 URL にリダイレクトされるようになりました。
- The `django.views.i18n.javascript_catalog()` view now works correctly if used multiple times with different configurations on the same page.
- `django.utils.timezone.make_aware()` 関数が `is_dst` 引数を取って、DST 中の曖昧な時間を適切に処理できるようになりました。
- gettext でサポートされるロケールの異なる文字が使えるようになりました。この機能は、たとえばラテン文字とキリル文字 (例: `be@latin`) のような異なる字体で書かれた言語でよく使われます。
- Added the `django.views.i18n.json_catalog()` view to help build a custom client-side i18n library upon Django translations. It returns a JSON object containing a translations catalog, formatting settings, and a plural rule.
- `get_language_info` テンプレートタグが返すオブジェクトに `name_translated` 属性が追加されました。また、対応するテンプレートフィルタ `language_name_translated` も追加します。
- プロジェクトのルートディレクトリから `compilemessages` を実行し、 `makemessages` で作成したアプリのメッセージのすべてを検索できます。
- `makemessages` now calls `xgettext` once per locale directory rather than once per translatable file. This speeds up localization builds.
- `blocktrans` が出力の値を `asvar` を使って変数に代入できるようになりました。
- コロンビアスペイン語とスコットランド・ゲール語の2つの言語が使用できるようになりました。

#### 管理コマンド

- 新しい `sendtestemail` コマンドが追加され、テストメールを送信して、Django 経由のメール送信が正常に動作しているかを簡単にチェックできるようになりました。
- `sqlmigrate` が生成する SQL コードのリーダビリティを向上するため、マイグレーション操作ごとに生成される SQL コードの前に、マイグレーション操作の説明を記述するようになりました。
- `dumpdata` コマンドの出力の順番が毎回同じ順番で表示されるようになりました。さらに、 `--output` オプションを指定すると、端末にプログレスバーも表示されるようになりました。
- `createcachetable` コマンドが `--dry-run` フラグを取れるようになり、SQL を実行せずに表示だけできるようになりました。
- The `startapp` command creates an `apps.py` file. Since it doesn't use `default_app_config` (a discouraged API), you must specify the app config's path, e.g. `'polls.apps.PollsConfig'`, in `INSTALLED_APPS` for it to be used (instead of just `'polls'`).
- When using the PostgreSQL backend, the `dbshell` command can connect to the database using the password from your settings file (instead of requiring it to be manually entered).
- The `django` package may be run as a script, i.e. `python -m django`, which will behave the same as `django-admin`.
- Management commands that have the `--noinput` option now also take `--no-input` as an alias for that option.

#### マイグレーション

- Initial migrations are now marked with an `initial = True` class attribute which allows `migrate --fake-initial` to more easily detect initial migrations.

- Added support for serialization of `functools.partial` and `LazyObject` instances.

- When supplying `None` as a value in `MIGRATION_MODULES`, Django will consider the app an app without migrations.

- When applying migrations, the "Rendering model states" step that's displayed when running migrate with verbosity 2 or higher now computes only the states for the migrations that have already been applied. The model states for migrations being applied are generated on demand, drastically reducing the amount of required memory.

  However, this improvement is not available when unapplying migrations and therefore still requires the precomputation and storage of the intermediate migration states.

  This improvement also requires that Django no longer supports mixed migration plans. Mixed plans consist of a list of migrations where some are being applied and others are being unapplied. This was never officially supported and never had a public API that supports this behavior.

- The `squashmigrations` command now supports specifying the starting migration from which migrations will be squashed.

#### モデル

- `QuerySet.bulk_create()` now works on proxy models.
- Database configuration gained a `TIME_ZONE` option for interacting with databases that store datetimes in local time and don't support time zones when `USE_TZ` is `True`.
- Added the `RelatedManager.set()` method to the related managers created by `ForeignKey`, `GenericForeignKey`, and `ManyToManyField`.
- The `add()` method on a reverse foreign key now has a `bulk` parameter to allow executing one query regardless of the number of objects being added rather than one query per object.
- Added the `keep_parents` parameter to `Model.delete()` to allow deleting only a child's data in a model that uses multi-table inheritance.
- `Model.delete()` and `QuerySet.delete()` return the number of objects deleted.
- Added a system check to prevent defining both `Meta.ordering` and `order_with_respect_to` on the same model.
- `Date and time` lookups can be chained with other lookups (such as `exact`, `gt`, `lt`, etc.). For example: `Entry.objects.filter(pub_date__month__gt=6)`.
- Time lookups (hour, minute, second) are now supported by `TimeField` for all database backends. Support for backends other than SQLite was added but undocumented in Django 1.7.
- You can specify the `output_field` parameter of the `Avg` aggregate in order to aggregate over non-numeric columns, such as `DurationField`.
- Added the `date` lookup to `DateTimeField` to allow querying the field by only the date portion.
- Added the `Greatest` and `Least` database functions.
- Added the `Now` database function, which returns the current date and time.
- `Transform` is now a subclass of Func() which allows `Transform`s to be used on the right hand side of an expression, just like regular `Func`s. This allows registering some database functions like `Length`, `Lower`, and `Upper` as transforms.
- `SlugField` now accepts an `allow_unicode` argument to allow Unicode characters in slugs.
- Added support for referencing annotations in `QuerySet.distinct()`.
- `connection.queries` shows queries with substituted parameters on SQLite.
- Query expressions can now be used when creating new model instances using `save()`, `create()`, and `bulk_create()`.

#### Request と Response

- Unless `HttpResponse.reason_phrase` is explicitly set, it now is determined by the current value of `HttpResponse.status_code`. Modifying the value of `status_code` outside of the constructor will also modify the value of `reason_phrase`.
- The debug view now shows details of chained exceptions on Python 3.
- The default 40x error views now accept a second positional parameter, the exception that triggered the view.
- View error handlers now support `TemplateResponse`, commonly used with class-based views.
- Exceptions raised by the `render()` method are now passed to the `process_exception()` method of each middleware.
- Request middleware can now set `HttpRequest.urlconf` to `None` to revert any changes made by previous middleware and return to using the `ROOT_URLCONF`.
- The `DISALLOWED_USER_AGENTS` check in `CommonMiddleware` now raises a `PermissionDenied` exception as opposed to returning an `HttpResponseForbidden` so that `handler403` is invoked.
- Added `HttpRequest.get_port()` to fetch the originating port of the request.
- Added the `json_dumps_params` parameter to `JsonResponse` to allow passing keyword arguments to the `json.dumps()` call used to generate the response.
- The `BrokenLinkEmailsMiddleware` now ignores 404s when the referer is equal to the requested URL. To circumvent the empty referer check already implemented, some web bots set the referer to the requested URL.

#### テンプレート

- Template tags created with the `simple_tag()` helper can now store results in a template variable by using the `as` argument.
- Added a `Context.setdefault()` method.
- The django.template logger was added and includes the following messages:
  - A `DEBUG` level message for missing context variables.
  - A `WARNING` level message for uncaught exceptions raised during the rendering of an `{% include %}` when debug mode is off (helpful since `{% include %}` silences the exception and returns an empty string).
- The `firstof` template tag supports storing the output in a variable using 'as'.
- `Context.update()` can now be used as a context manager.
- Django template loaders can now extend templates recursively.
- The debug page template postmortem now include output from each engine that is installed.
- Debug page integration for custom template engines was added.
- The `DjangoTemplates` backend gained the ability to register libraries and builtins explicitly through the template `OPTIONS`.
- The `timesince` and `timeuntil` filters were improved to deal with leap years when given large time spans.
- The `include` tag now caches parsed templates objects during template rendering, speeding up reuse in places such as for loops.

#### テスト

- Added the `json()` method to test client responses to give access to the response body as JSON.
- Added the `force_login()` method to the test client. Use this method to simulate the effect of a user logging into the site while skipping the authentication and verification steps of `login()`.

#### URL

- Regular expression lookaround assertions are now allowed in URL patterns.
- The application namespace can now be set using an `app_name` attribute on the included module or object. It can also be set by passing a 2-tuple of (<list of patterns>, <application namespace>) as the first argument to `include()`.
- System checks have been added for common URL pattern mistakes.

#### バリデータ

- Added `django.core.validators.int_list_validator()` to generate validators of strings containing integers separated with a custom character.
- `EmailValidator` now limits the length of domain name labels to 63 characters per RFC 1034.
- Added `validate_unicode_slug()` to validate slugs that may contain Unicode characters.

## Backwards incompatible changes in 1.9

警告

In addition to the changes outlined in this section, be sure to review the 1.9 で削除された機能 for the features that have reached the end of their deprecation cycle and therefore been removed. If you haven't updated your code within the deprecation timeline for a given feature, its removal may appear as a backwards incompatible change.

### データベースバックエンド API

- A couple of new tests rely on the ability of the backend to introspect column defaults (returning the result as `Field.default`). You can set the `can_introspect_default` database feature to `False` if your backend doesn't implement this. You may want to review the implementation on the backends that Django includes for reference (#24245).

- Registering a global adapter or converter at the level of the DB-API module to handle time zone information of `datetime` values passed as query parameters or returned as query results on databases that don't support time zones is discouraged. It can conflict with other libraries.

  The recommended way to add a time zone to `datetime` values fetched from the database is to register a converter for `DateTimeField` in `DatabaseOperations.get_db_converters()`.

  The `needs_datetime_string_cast` database feature was removed. Database backends that set it must register a converter instead, as explained above.

- The `DatabaseOperations.value_to_db_<type>()` methods were renamed to `adapt_<type>field_value()` to mirror the `convert_<type>field_value()` methods.

- To use the new `date` lookup, third-party database backends may need to implement the `DatabaseOperations.datetime_cast_date_sql()` method.

- The `DatabaseOperations.time_extract_sql()` method was added. It calls the existing `date_extract_sql()` method. This method is overridden by the SQLite backend to add time lookups (hour, minute, second) to `TimeField`, and may be needed by third-party database backends.

- The `DatabaseOperations.datetime_cast_sql()` method (not to be confused with `DatabaseOperations.datetime_cast_date_sql()` mentioned above) has been removed. This method served to format dates on Oracle long before 1.0, but hasn't been overridden by any core backend in years and hasn't been called anywhere in Django's code or tests.

- In order to support test parallelization, you must implement the `DatabaseCreation._clone_test_db()` method and set `DatabaseFeatures.can_clone_databases = True`. You may have to adjust `DatabaseCreation.get_test_db_clone_settings()`.

### Default settings that were tuples are now lists

The default settings in `django.conf.global_settings` were a combination of lists and tuples. All settings that were formerly tuples are now lists.

### `is_usable` attribute on template loaders is removed

Django template loaders previously required an `is_usable` attribute to be defined. If a loader was configured in the template settings and this attribute was `False`, the loader would be silently ignored. In practice, this was only used by the egg loader to detect if setuptools was installed. The `is_usable` attribute is now removed and the egg loader instead fails at runtime if setuptools is not installed.

### Related set direct assignment

Direct assignment of related objects in the ORM used to perform a `clear()` followed by a call to `add()`. This caused needlessly large data changes and prevented using the `m2m_changed` signal to track individual changes in many-to-many relations.

Direct assignment now relies on the new `set()` method on related managers which by default only processes changes between the existing related set and the one that's newly assigned. The previous behavior can be restored by replacing direct assignment by a call to `set()` with the keyword argument `clear=True`.

`ModelForm`, and therefore `ModelAdmin`, internally rely on direct assignment for many-to-many relations and as a consequence now use the new behavior.

### Filesystem-based template loaders catch more specific exceptions

When using the `filesystem.Loader` or `app_directories.Loader` template loaders, earlier versions of Django raised a `TemplateDoesNotExist` error if a template source existed but was unreadable. This could happen under many circumstances, such as if Django didn't have permissions to open the file, or if the template source was a directory. Now, Django only silences the exception if the template source does not exist. All other situations result in the original `IOError` being raised.

### HTTP redirects no longer forced to absolute URIs

Relative redirects are no longer converted to absolute URIs. RFC 2616 required the `Location` header in redirect responses to be an absolute URI, but it has been superseded by RFC 7231 which allows relative URIs in `Location`, recognizing the actual practice of user agents, almost all of which support them.

Consequently, the expected URLs passed to `assertRedirects` should generally no longer include the scheme and domain part of the URLs. For example, `self.assertRedirects(response, 'http://testserver/some-url/')` should be replaced by `self.assertRedirects(response, '/some-url/')` (unless the redirection specifically contained an absolute URL).

In the rare case that you need the old behavior (discovered with an ancient version of Apache with `mod_scgi` that interprets a relative redirect as an "internal redirect"), you can restore it by writing a custom middleware:

    class LocationHeaderFix(object):
        def process_response(self, request, response):
            if 'Location' in response:
                response['Location'] = request.build_absolute_uri(response['Location'])
            return response

### Dropped support for PostgreSQL 9.0

Upstream support for PostgreSQL 9.0 ended in September 2015. As a consequence, Django 1.9 sets 9.1 as the minimum PostgreSQL version it officially supports.

### Dropped support for Oracle 11.1

Upstream support for Oracle 11.1 ended in August 2015. As a consequence, Django 1.9 sets 11.2 as the minimum Oracle version it officially supports.

### Bulk behavior of `add()` method of related managers

To improve performance, the `add()` methods of the related managers created by `ForeignKey` and `GenericForeignKey` changed from a series of `Model.save()` calls to a single `QuerySet.update()` call. The change means that `pre_save` and `post_save` signals aren't sent anymore. You can use the `bulk=False` keyword argument to revert to the previous behavior.

### Template `LoaderOrigin` and `StringOrigin` are removed

In previous versions of Django, when a template engine was initialized with debug as `True`, an instance of `django.template.loader.LoaderOrigin` or `django.template.base.StringOrigin` was set as the origin attribute on the template object. These classes have been combined into `Origin` and is now always set regardless of the engine debug setting. For a minimal level of backwards compatibility, the old class names will be kept as aliases to the new `Origin` class until Django 2.0.

### Changes to the default logging configuration

To make it easier to write custom logging configurations, Django's default logging configuration no longer defines `django.request` and `django.security` loggers. Instead, it defines a single `django` logger, filtered at the `INFO` level, with two handlers:

- `console`: filtered at the `INFO` level and only active if `DEBUG=True`.
- `mail_admins`: filtered at the `ERROR` level and only active if `DEBUG=False`.

If you aren't overriding Django's default logging, you should see minimal changes in behavior, but you might see some new logging to the `runserver` console, for example.

If you are overriding Django's default logging, you should check to see how your configuration merges with the new defaults.

### `HttpRequest` details in error reporting

It was redundant to display the full details of the `HttpRequest` each time it appeared as a stack frame variable in the HTML version of the debug page and error email. Thus, the HTTP request will now display the same standard representation as other variables (`repr(request)`). As a result, the `ExceptionReporterFilter.get_request_repr()` method and the undocumented `django.http.build_request_repr()` function were removed.

The contents of the text version of the email were modified to provide a traceback of the same structure as in the case of AJAX requests. The traceback details are rendered by the `ExceptionReporter.get_traceback_text()` method.

### Removal of time zone aware global adapters and converters for datetimes

Django no longer registers global adapters and converters for managing time zone information on `datetime` values sent to the database as query parameters or read from the database in query results. This change affects projects that meet all the following conditions:

- The `USE_TZ` setting is `True`.
- The database is SQLite, MySQL, Oracle, or a third-party database that doesn't support time zones. In doubt, you can check the value of `connection.features.supports_timezones`.
- The code queries the database outside of the ORM, typically with `cursor.execute(sql, params)`.

If you're passing aware `datetime` parameters to such queries, you should turn them into naive datetimes in UTC:

    from django.utils import timezone
    param = timezone.make_naive(param, timezone.utc)

If you fail to do so, the conversion will be performed as in earlier versions (with a deprecation warning) up until Django 1.11. Django 2.0 won't perform any conversion, which may result in data corruption.

If you're reading `datetime` values from the results, they will be naive instead of aware. You can compensate as follows:

    from django.utils import timezone
    value = timezone.make_aware(value, timezone.utc)

You don't need any of this if you're querying the database through the ORM, even if you're using `raw()` queries. The ORM takes care of managing time zone information.

### Template tag modules are imported when templates are configured

The `DjangoTemplates` backend now performs discovery on installed template tag modules when instantiated. This update enables libraries to be provided explicitly via the `'libraries'` key of `OPTIONS` when defining a `DjangoTemplates` backend. Import or syntax errors in template tag modules now fail early at instantiation time rather than when a template with a `{% load %}` tag is first compiled.

### `django.template.base.add_to_builtins()` is removed

Although it was a private API, projects commonly used `add_to_builtins()` to make template tags and filters available without using the `{% load %}` tag. This API has been formalized. Projects should now define built-in libraries via the `'builtins'` key of `OPTIONS` when defining a `DjangoTemplates` backend.

### `simple_tag` now wraps tag output in `conditional_escape`

In general, template tags do not autoescape their contents, and this behavior is documented. For tags like `inclusion_tag`, this is not a problem because the included template will perform autoescaping. For `assignment_tag()`, the output will be escaped when it is used as a variable in the template.

For the intended use cases of `simple_tag`, however, it is very easy to end up with incorrect HTML and possibly an XSS exploit. For example:

    @register.simple_tag(takes_context=True)
    def greeting(context):
        return "Hello {0}!".format(context['request'].user.first_name)

In older versions of Django, this will be an XSS issue because `user.first_name` is not escaped.

In Django 1.9, this is fixed: if the template context has `autoescape=True` set (the default), then `simple_tag` will wrap the output of the tag function with `conditional_escape()`.

To fix your `simple_tag`s, it is best to apply the following practices:

- Any code that generates HTML should use either the template system or `format_html()`.
- If the output of a `simple_tag` needs escaping, use `escape()` or `conditional_escape()`.
- If you are absolutely certain that you are outputting HTML from a trusted source (e.g. a CMS field that stores HTML entered by admins), you can mark it as such using `mark_safe()`.

Tags that follow these rules will be correct and safe whether they are run on Django 1.9+ or earlier.

### `Paginator.page_range`

`Paginator.page_range` is now an iterator instead of a list.

In versions of Django previous to 1.8, `Paginator.page_range` returned a `list` in Python 2 and a `range` in Python 3. Django 1.8 consistently returned a list, but an iterator is more efficient.

Existing code that depends on `list` specific features, such as indexing, can be ported by converting the iterator into a `list` using `list()`.

### Implicit `QuerySet` `__in` lookup removed

In earlier versions, queries such as:

    Model.objects.filter(related_id=RelatedModel.objects.all())

would implicitly convert to:

    Model.objects.filter(related_id__in=RelatedModel.objects.all())

resulting in SQL like `"related_id IN (SELECT id FROM ...)"`.

This implicit `__in` no longer happens so the "IN" SQL is now "=", and if the subquery returns multiple results, at least some databases will throw an error.

### `contrib.admin` browser support

The admin no longer supports Internet Explorer 8 and below, as these browsers have reached end-of-life.

CSS and images to support Internet Explorer 6 and 7 have been removed. PNG and GIF icons have been replaced with SVG icons, which are not supported by Internet Explorer 8 and earlier.

The jQuery library embedded in the admin has been upgraded from version 1.11.2 to 2.1.4. jQuery 2.x has the same API as jQuery 1.x, but does not support Internet Explorer 6, 7, or 8, allowing for better performance and a smaller file size. If you need to support IE8 and must also use the latest version of Django, you can override the admin's copy of jQuery with your own by creating a Django application with this structure:

    app/static/admin/js/vendor/
        jquery.js
        jquery.min.js

### `SyntaxError` when installing Django setuptools 5.5.x

When installing Django 1.9 or 1.9.1 with setuptools 5.5.x, you'll see:

    Compiling django/conf/app_template/apps.py ...
      File "django/conf/app_template/apps.py", line 4
        class {{ camel_case_app_name }}Config(AppConfig):
              ^
    SyntaxError: invalid syntax

    Compiling django/conf/app_template/models.py ...
      File "django/conf/app_template/models.py", line 1
        {{ unicode_literals }}from django.db import models
                                 ^
    SyntaxError: invalid syntax

It's safe to ignore these errors (Django will still install just fine), but you can avoid them by upgrading setuptools to a more recent version. If you're using pip, you can upgrade pip using `python -m pip install -U pip` which will also upgrade setuptools. This is resolved in later versions of Django as described in the Django 1.9.2 リリースノート.

### その他

- The jQuery static files in `contrib.admin` have been moved into a `vendor/jquery` subdirectory.
- The text displayed for null columns in the admin changelist `list_display` cells has changed from `(None)` (or its translated equivalent) to `-` (a dash).
- `django.http.responses.REASON_PHRASES` and `django.core.handlers.wsgi.STATUS_CODE_TEXT` have been removed. Use Python's Standard Library instead: `http.client.responses` for Python 3 and httplib.responses for Python 2.
- `ValuesQuerySet` and `ValuesListQuerySet` have been removed.
- The `admin/base.html` template no longer sets `window.__admin_media_prefix__` or `window.__admin_utc_offset__`. Image references in JavaScript that used that value to construct absolute URLs have been moved to CSS for easier customization. The UTC offset is stored on a data attribute of the `<body>` tag.
- `CommaSeparatedIntegerField` validation has been refined to forbid values like `','`, `',1'`, and `'1,,2'`.
- Form initialization was moved from the `ProcessFormView.get()` method to the new `FormMixin.get_context_data()` method. This may be backwards incompatible if you have overridden the `get_context_data()` method without calling `super()`.
- Support for PostGIS 1.5 has been dropped.
- The `django.contrib.sites.models.Site.domain` field was changed to be `unique`.
- In order to enforce test isolation, database queries are not allowed by default in `SimpleTestCase` tests anymore. You can disable this behavior by setting the `allow_database_queries` class attribute to `True` on your test class.
- `ResolverMatch.app_name` was changed to contain the full namespace path in the case of nested namespaces. For consistency with `ResolverMatch.namespace`, the empty value is now an empty string instead of `None`.
- For security hardening, session keys must be at least 8 characters.
- Private function `django.utils.functional.total_ordering()` has been removed. It contained a workaround for a `functools.total_ordering()` bug in Python versions older than 2.7.3.
- XML serialization (either through `dumpdata` or the syndication framework) used to output any characters it received. Now if the content to be serialized contains any control characters not allowed in the XML 1.0 standard, the serialization will fail with a `ValueError`.
- `CharField` now strips input of leading and trailing whitespace by default. This can be disabled by setting the new `strip` argument to `False`.
- Template text that is translated and uses two or more consecutive percent signs, e.g. `"%%"`, may have a new `msgid` after `makemessages` is run (most likely the translation will be marked fuzzy). The new `msgid` will be marked `"#, python-format"`.
- If neither `request.current_app` nor `Context.current_app` are set, the `url` template tag will now use the namespace of the current request. Set `request.current_app` to `None` if you don't want to use a namespace hint.
- The `SILENCED_SYSTEM_CHECKS` setting now silences messages of all levels. Previously, messages of `ERROR` level or higher were printed to the console.
- The `FlatPage.enable_comments` field is removed from the `FlatPageAdmin` as it's unused by the application. If your project or a third-party app makes use of it, create a custom ModelAdmin to add it back.
- The return value of `setup_databases()` and the first argument of `teardown_databases()` changed. They used to be `(old_names, mirrors)` tuples. Now they're just the first item, `old_names`.
- By default `LiveServerTestCase` attempts to find an available port in the 8081-8179 range instead of just trying port 8081.
- The system checks for `ModelAdmin` now check instances rather than classes.
- The private API to apply mixed migration plans has been dropped for performance reasons. Mixed plans consist of a list of migrations where some are being applied and others are being unapplied.
- The related model object descriptor classes in `django.db.models.fields.related` (private API) are moved from the `related` module to `related_descriptors` and renamed as follows:
  - `ReverseSingleRelatedObjectDescriptor` is `ForwardManyToOneDescriptor`
  - `SingleRelatedObjectDescriptor` is `ReverseOneToOneDescriptor`
  - `ForeignRelatedObjectsDescriptor` is `ReverseManyToOneDescriptor`
  - `ManyRelatedObjectsDescriptor` is `ManyToManyDescriptor`
- If you implement a custom `handler404` view, it must return a response with an HTTP 404 status code. Use `HttpResponseNotFound` or pass `status=404` to the `HttpResponse`. Otherwise, `APPEND_SLASH` won't work correctly with `DEBUG=False`.

## Features deprecated in 1.9

### `assignment_tag()`

Django 1.4 added the `assignment_tag` helper to ease the creation of template tags that store results in a template variable. The `simple_tag()` helper has gained this same ability, making the `assignment_tag` obsolete. Tags that use `assignment_tag` should be updated to use `simple_tag`.

### `{% cycle %}` syntax with comma-separated arguments

The `cycle` tag supports an inferior old syntax from previous Django versions:

    {% cycle row1,row2,row3 %}

Its parsing caused bugs with the current syntax, so support for the old syntax will be removed in Django 1.10 following an accelerated deprecation.

### `ForeignKey` and `OneToOneField` `on_delete` argument

In order to increase awareness about cascading model deletion, the `on_delete` argument of `ForeignKey` and `OneToOneField` will be required in Django 2.0.

Update models and existing migrations to explicitly set the argument. Since the default is `models.CASCADE`, add `on_delete=models.CASCADE` to all `ForeignKey` and `OneToOneField`s that don't use a different option. You can also pass it as the second positional argument if you don't care about compatibility with older versions of Django.

### `Field.rel` changes

`Field.rel` and its methods and attributes have changed to match the related fields API. The `Field.rel` attribute is renamed to `remote_field` and many of its methods and attributes are either changed or renamed.

The aim of these changes is to provide a documented API for relation fields.

### `GeoManager` and `GeoQuerySet` custom methods

All custom `GeoQuerySet` methods (`area()`, `distance()`, `gml()`, ...) have been replaced by equivalent geographic expressions in annotations (see in new features). Hence the need to set a custom `GeoManager` to GIS-enabled models is now obsolete. As soon as your code doesn't call any of the deprecated methods, you can simply remove the `objects = GeoManager()` lines from your models.

### Template loader APIs have changed

Django template loaders have been updated to allow recursive template extending. This change necessitated a new template loader API. The old `load_template()` and `load_template_sources()` methods are now deprecated. Details about the new API can be found in the template loader documentation.

### Passing a 3-tuple or an `app_name` to `include()`

The instance namespace part of passing a tuple as an argument to `include()` has been replaced by passing the `namespace` argument to `include()`. For example:

    polls_patterns = [
         url(...),
    ]

    urlpatterns = [
        url(r'^polls/', include((polls_patterns, 'polls', 'author-polls'))),
    ]

は、以下のようになります:

    polls_patterns = ([
         url(...),
    ], 'polls')  # 'polls' is the app_name

    urlpatterns = [
        url(r'^polls/', include(polls_patterns, namespace='author-polls')),
    ]

The `app_name` argument to `include()` has been replaced by passing a 2-tuple (as above), or passing an object or module with an `app_name` attribute (as below). If the `app_name` is set in this new way, the `namespace` argument is no longer required. It will default to the value of `app_name`. For example, the URL patterns in the tutorial are changed from:

`mysite/urls.py`

    urlpatterns = [
        url(r'^polls/', include('polls.urls', namespace="polls")),
        ...
    ]

to:

`mysite/urls.py`

    urlpatterns = [
        url(r'^polls/', include('polls.urls')),  # 'namespace="polls"' removed
        ...
    ]

`polls/urls.py`

    app_name = 'polls'  # added
    urlpatterns = [...]

This change also means that the old way of including an `AdminSite` instance is deprecated. Instead, pass `admin.site.urls` directly to `django.conf.urls.url()`:

`urls.py`

    from django.conf.urls import url
    from django.contrib import admin

    urlpatterns = [
        url(r'^admin/', admin.site.urls),
    ]

### URL application namespace required if setting an instance namespace

In the past, an instance namespace without an application namespace would serve the same purpose as the application namespace, but it was impossible to reverse the patterns if there was an application namespace with the same name. Includes that specify an instance namespace require that the included URLconf sets an application namespace.

### `current_app` parameter to `contrib.auth` views

All views in `django.contrib.auth.views` have the following structure:

    def view(request, ..., current_app=None, ...):

        ...

        if current_app is not None:
            request.current_app = current_app

        return TemplateResponse(request, template_name, context)

As of Django 1.8, `current_app` is set on the `request` object. For consistency, these views will require the caller to set `current_app` on the `request` instead of passing it in a separate argument.

### `django.contrib.gis.geoip`

The `django.contrib.gis.geoip2` module supersedes `django.contrib.gis.geoip`. The new module provides a similar API except that it doesn't provide the legacy GeoIP-Python API compatibility methods.

### その他

- The `weak` argument to `django.dispatch.signals.Signal.disconnect()` has been deprecated as it has no effect.
- The `check_aggregate_support()` method of `django.db.backends.base.BaseDatabaseOperations` has been deprecated and will be removed in Django 2.0. The more general `check_expression_support()` should be used instead.
- `django.forms.extras` is deprecated. You can find `SelectDateWidget` in `django.forms.widgets` (or simply `django.forms`) instead.
- Private API `django.db.models.fields.add_lazy_relation()` is deprecated.
- The `django.contrib.auth.tests.utils.skipIfCustomUser()` decorator is deprecated. With the test discovery changes in Django 1.6, the tests for `django.contrib` apps are no longer run as part of the user's project. Therefore, the `@skipIfCustomUser` decorator is no longer needed to decorate tests in `django.contrib.auth`.
- If you customized some error handlers, the view signatures with only one request parameter are deprecated. The views should now also accept a second `exception` positional parameter.
- The `django.utils.feedgenerator.Atom1Feed.mime_type` and `django.utils.feedgenerator.RssFeed.mime_type` attributes are deprecated in favor of `content_type`.
- `Signer` now issues a warning if an invalid separator is used. This will become an exception in Django 1.10.
- `django.db.models.Field._get_val_from_obj()` is deprecated in favor of `Field.value_from_object()`.
- `django.template.loaders.eggs.Loader` is deprecated as distributing applications as eggs is not recommended.
- The `callable_obj` keyword argument to `SimpleTestCase.assertRaisesMessage()` is deprecated. Pass the callable as a positional argument instead.
- The `allow_tags` attribute on methods of `ModelAdmin` has been deprecated. Use `format_html()`, `format_html_join()`, or `mark_safe()` when constructing the method's return value instead.
- The `enclosure` keyword argument to `SyndicationFeed.add_item()` is deprecated. Use the new `enclosures` argument which accepts a list of `Enclosure` objects instead of a single one.
- The `django.template.loader.LoaderOrigin` and `django.template.base.StringOrigin` aliases for `django.template.base.Origin` are deprecated.

## 1.9 で削除された機能

以下の機能は、非推奨サイクルの終わりに達したため、Django 1.9 で削除されます。詳しくは Features deprecated in 1.7 を見てください。ここには、プロジェクトからこれらの機能を削除する方法についても書かれています。

- `django.utils.dictconfig` が削除されました。
- `django.utils.importlib` が削除されました。
- `django.utils.tzinfo` が削除されました。
- `django.utils.unittest` が削除されました。
- `syncdb` コマンドが削除されました。
- `django.db.models.signals.pre_syncdb` と `django.db.models.signals.post_syncdb` が削除されました。
- データベースルータ上の `allow_syncdb` へのサポートが削除されました。
- Automatic syncing of apps without migrations is removed. Migrations are compulsory for all apps unless you pass the `migrate --run-syncdb` option.
- The SQL management commands for apps without migrations, `sql`, `sqlall`, `sqlclear`, `sqldropindexes`, and `sqlindexes`, are removed.
- Support for automatic loading of `initial_data` fixtures and initial SQL data is removed.
- All models need to be defined inside an installed application or declare an explicit `app_label`. Furthermore, it isn't possible to import them before their application is loaded. In particular, it isn't possible to import models inside the root package of an application.
- The model and form `IPAddressField` is removed. A stub field remains for compatibility with historical migrations.
- `AppCommand.handle_app()` is no longer supported.
- `RequestSite` and `get_current_site()` are no longer importable from `django.contrib.sites.models`.
- FastCGI support via the `runfcgi` management command is removed.
- `django.utils.datastructures.SortedDict` が削除されました。
- `ModelAdmin.declared_fieldsets` が削除されました。
- 後方互換性のために提供されていた `util` が削除されました。
  - `django.contrib.admin.util`
  - `django.contrib.gis.db.backends.util`
  - `django.db.backends.util`
  - `django.forms.util`
- `ModelAdmin.get_formsets` が削除されました。
- The backward compatible shims introduced to rename the `BaseMemcachedCache._get_memcache_timeout()` method to `get_backend_timeout()` is removed.
- `dumpdata` の `--natural` および `-n` オプションが削除されました。
- `serializers.serialize()` の `use_natural_keys` 引数が削除されました。
- プライベート API `django.forms.forms.get_declared_fields()` が削除されました。
- `DateTimeField` で `SplitDateTimeWidget` が使用できなくなりました。
- `WSGIRequest.REQUEST` 属性が削除されました。
- `django.utils.datastructures.MergeDict` クラスが削除されました。
- `zh-cn` および `zh-tw` 言語コードが削除されました。
- 内部で使われていた `django.utils.functional.memoize()` が削除されました。
- `django.core.cache.get_cache` が削除されました。
- `django.db.models.loading` が削除されました。
- Passing callable arguments to querysets is no longer possible.
- `BaseCommand.requires_model_validation` is removed in favor of `requires_system_checks`. Admin validators is replaced by admin checks.
- The `ModelAdmin.validator_class` and `default_validator_class` attributes are removed.
- `ModelAdmin.validate()` が削除されました。
- `django.db.backends.DatabaseValidation.validate_field` is removed in favor of the `check_field` method.
- `validate` 管理コマンドが削除されました。
- `django.utils.module_loading.import_string` があるため、`django.utils.module_loading.import_by_path` が削除されました。
- `future` テンプレートタグライブラリから `ssi` と `url` テンプレートタグが削除されました。
- `django.utils.text.javascript_quote()` が削除されました。
- Database test settings as independent entries in the database settings, prefixed by `TEST_`, are no longer supported.
- The `cache_choices` option to `ModelChoiceField` and `ModelMultipleChoiceField` is removed.
- The default value of the `RedirectView.permanent` attribute has changed from `True` to `False`.
- `django.contrib.sitemaps.FlatPageSitemap` is removed in favor of `django.contrib.flatpages.sitemaps.FlatPageSitemap`.
- Private API `django.test.utils.TestTemplateLoader` is removed.
- The `django.contrib.contenttypes.generic` module is removed.