2.0.txt 28 KB

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280281282283284285286287288289290291292293294295296297298299300301302303304305306307308309310311312313314315316317318319320321322323324325326327328329330331332333334335336337338339340341342343344345346347348349350351352353354355356357358359360361362363364365366367368369370371372373374375376377378379380381382383384385386387388389390391392393394395396397398399400401402403404405406407408409410411412413414415416417418419420421422423424425426427428429430431432433434435436437438439440441442443444445446447448449450451452453454455456457458459460461462463464465466467468469470471472473474475476477478479480481482483484485486487488489490491492493494495496497498499500501502503504505506507508509510511512513514515516517518519520521522523524525526527528529530531532533534535536537538539540541542543544545546547548549550551552553554555556557558559560561562563564565566567568569570571572573574575576577578579580581582583584585586587588589590591592593594595596597598599600601602603604605606607608609610611612613614615616617618619620621622623624625626627628629630631632633634635636637638639640641642643644645646647648649650651652653654655656657658659660661662663664665666667668669670671672673674675676677678679680681682683684685686687688689690691692693694695696697698699700701702703704705706707708709710711712713714715716717718719720721722723724725726727728729730731732733734735736737738739740741742743744745746747748749750751752753754755756757758759760761762763764765766767768769770771772773774775776777778779780781782783784785786787788789790791792793794795796797798799800801
  1. ============================================
  2. Django 2.0 release notes - UNDER DEVELOPMENT
  3. ============================================
  4. Welcome to Django 2.0!
  5. These release notes cover the :ref:`new features <whats-new-2.0>`, as well as
  6. some :ref:`backwards incompatible changes <backwards-incompatible-2.0>` you'll
  7. want to be aware of when upgrading from Django 1.11 or earlier. We've
  8. :ref:`dropped some features<removed-features-2.0>` that have reached the end of
  9. their deprecation cycle, and we've :ref:`begun the deprecation process for some
  10. features <deprecated-features-2.0>`.
  11. See the :doc:`/howto/upgrade-version` guide if you're updating an existing
  12. project.
  13. Python compatibility
  14. ====================
  15. Django 2.0 supports Python 3.4, 3.5, and 3.6. We **highly recommend** and only
  16. officially support the latest release of each series.
  17. The Django 1.11.x series is the last to support Python 2.7.
  18. Django 2.0 will be the last release series to support Python 3.4. If you plan
  19. a deployment of Python 3.4 beyond the end-of-life for Django 2.0 (April 2019),
  20. stick with Django 1.11 LTS (supported until April 2020) instead. Note, however,
  21. that the end-of-life for Python 3.4 is March 2019.
  22. Third-party library support for older version of Django
  23. =======================================================
  24. Following the release of Django 2.0, we suggest that third-party app authors
  25. drop support for all versions of Django prior to 1.11. At that time, you should
  26. be able run your package's tests using ``python -Wd`` so that deprecation
  27. warnings do appear. After making the deprecation warning fixes, your app should
  28. be compatible with Django 2.0.
  29. .. _whats-new-2.0:
  30. What's new in Django 2.0
  31. ========================
  32. Minor features
  33. --------------
  34. :mod:`django.contrib.admin`
  35. ~~~~~~~~~~~~~~~~~~~~~~~~~~~
  36. * ...
  37. :mod:`django.contrib.admindocs`
  38. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  39. * ...
  40. :mod:`django.contrib.auth`
  41. ~~~~~~~~~~~~~~~~~~~~~~~~~~
  42. * The default iteration count for the PBKDF2 password hasher is increased from
  43. 36,000 to 100,000.
  44. :mod:`django.contrib.contenttypes`
  45. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  46. * ...
  47. :mod:`django.contrib.gis`
  48. ~~~~~~~~~~~~~~~~~~~~~~~~~
  49. * Added MySQL support for the
  50. :class:`~django.contrib.gis.db.models.functions.AsGeoJSON` function,
  51. :class:`~django.contrib.gis.db.models.functions.GeoHash` function,
  52. :class:`~django.contrib.gis.db.models.functions.IsValid` function,
  53. :lookup:`isvalid` lookup, and :ref:`distance lookups <distance-lookups>`.
  54. * Added the :class:`~django.contrib.gis.db.models.functions.Azimuth` and
  55. :class:`~django.contrib.gis.db.models.functions.LineLocatePoint` functions,
  56. supported on PostGIS and SpatiaLite.
  57. * Any :class:`~django.contrib.gis.geos.GEOSGeometry` imported from GeoJSON now
  58. has its SRID set.
  59. * Added the :attr:`.OSMWidget.default_zoom` attribute to customize the map's
  60. default zoom level.
  61. * Made metadata readable and editable on rasters through the
  62. :attr:`~django.contrib.gis.gdal.GDALRaster.metadata`,
  63. :attr:`~django.contrib.gis.gdal.GDALRaster.info`, and
  64. :attr:`~django.contrib.gis.gdal.GDALBand.metadata` attributes.
  65. * Allowed passing driver-specific creation options to
  66. :class:`~django.contrib.gis.gdal.GDALRaster` objects using ``papsz_options``.
  67. * Allowed creating :class:`~django.contrib.gis.gdal.GDALRaster` objects in
  68. GDAL's internal virtual filesystem. Rasters can now be :ref:`created from and
  69. converted to binary data <gdal-raster-vsimem>` in-memory.
  70. :mod:`django.contrib.messages`
  71. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  72. * ...
  73. :mod:`django.contrib.postgres`
  74. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  75. * The new ``distinct`` argument for
  76. :class:`~django.contrib.postgres.aggregates.ArrayAgg` determines if
  77. concatenated values will be distinct.
  78. * The new :class:`~django.contrib.postgres.functions.RandomUUID` database
  79. function returns a version 4 UUID. It requires use of PostgreSQL's
  80. ``pgcrypto`` extension which can be activated using the new
  81. :class:`~django.contrib.postgres.operations.CryptoExtension` migration
  82. operation.
  83. * :class:`django.contrib.postgres.indexes.GinIndex` now supports the
  84. ``fastupdate`` and ``gin_pending_list_limit`` parameters.
  85. :mod:`django.contrib.redirects`
  86. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  87. * ...
  88. :mod:`django.contrib.sessions`
  89. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  90. * ...
  91. :mod:`django.contrib.sitemaps`
  92. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  93. * Added the ``protocol`` keyword argument to the
  94. :class:`~django.contrib.sitemaps.GenericSitemap` constructor.
  95. :mod:`django.contrib.sites`
  96. ~~~~~~~~~~~~~~~~~~~~~~~~~~~
  97. * ...
  98. :mod:`django.contrib.staticfiles`
  99. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  100. * ...
  101. :mod:`django.contrib.syndication`
  102. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  103. * ...
  104. Cache
  105. ~~~~~
  106. * ...
  107. CSRF
  108. ~~~~
  109. * ...
  110. Database backends
  111. ~~~~~~~~~~~~~~~~~
  112. * ...
  113. Email
  114. ~~~~~
  115. * ...
  116. File Storage
  117. ~~~~~~~~~~~~
  118. * :meth:`File.open() <django.core.files.File.open>` can be used as a context
  119. manager, e.g. ``with file.open() as f:``.
  120. File Uploads
  121. ~~~~~~~~~~~~
  122. * ...
  123. Forms
  124. ~~~~~
  125. * The new ``date_attrs`` and ``time_attrs`` arguments for
  126. :class:`~django.forms.SplitDateTimeWidget` and
  127. :class:`~django.forms.SplitHiddenDateTimeWidget` allow specifying different
  128. HTML attributes for the ``DateInput`` and ``TimeInput`` (or hidden)
  129. subwidgets.
  130. * The new :meth:`Form.errors.get_json_data()
  131. <django.forms.Form.errors.get_json_data>` method returns form errors as
  132. a dictionary suitable for including in a JSON response.
  133. Generic Views
  134. ~~~~~~~~~~~~~
  135. * The new :attr:`.ContextMixin.extra_context` attribute allows adding context
  136. in ``View.as_view()``.
  137. Internationalization
  138. ~~~~~~~~~~~~~~~~~~~~
  139. * ...
  140. Management Commands
  141. ~~~~~~~~~~~~~~~~~~~
  142. * :djadmin:`inspectdb` now translates MySQL's unsigned integer columns to
  143. ``PositiveIntegerField`` or ``PositiveSmallIntegerField``.
  144. * The new :option:`makemessages --add-location` option controls the comment
  145. format in PO files.
  146. * :djadmin:`loaddata` can now :ref:`read from stdin <loading-fixtures-stdin>`.
  147. * The new :option:`diffsettings --output` option allows formatting the output
  148. in a unified diff format.
  149. * On Oracle, :djadmin:`inspectdb` can now introspect ``AutoField`` if the
  150. column is created as an identity column.
  151. * On MySQL, :djadmin:`dbshell` now supports client-side TLS certificates.
  152. Migrations
  153. ~~~~~~~~~~
  154. * The new :option:`squashmigrations --squashed-name` option allows naming
  155. the squashed migration.
  156. Models
  157. ~~~~~~
  158. * The new :class:`~django.db.models.functions.StrIndex` database function
  159. finds the starting index of a string inside another string.
  160. * On Oracle, ``AutoField`` and ``BigAutoField`` are now created as `identity
  161. columns`_.
  162. .. _`identity columns`: https://docs.oracle.com/database/121/DRDAA/migr_tools_feat.htm#DRDAA109
  163. * The new ``chunk_size`` parameter of :meth:`.QuerySet.iterator` controls the
  164. number of rows fetched by the Python database client when streaming results
  165. from the database. For databases that don't support server-side cursors, it
  166. controls the number of results Django fetches from the database adapter.
  167. * Added the :class:`~django.db.models.functions.datetime.ExtractQuarter`
  168. function to extract the quarter from :class:`~django.db.models.DateField` and
  169. :class:`~django.db.models.DateTimeField`, and exposed it through the
  170. :lookup:`quarter` lookup.
  171. * Added the :class:`~django.db.models.functions.datetime.TruncQuarter`
  172. function to truncate :class:`~django.db.models.DateField` and
  173. :class:`~django.db.models.DateTimeField` to the first day of a quarter.
  174. * Added the :attr:`~django.db.models.Index.db_tablespace` parameter to
  175. class-based indexes.
  176. * If the database supports a native duration field (Oracle and PostgreSQL),
  177. :class:`~django.db.models.functions.datetime.Extract` now works with
  178. :class:`~django.db.models.DurationField`.
  179. * Added the ``of`` argument to :meth:`.QuerySet.select_for_update()`, supported
  180. on PostgreSQL and Oracle, to lock only rows from specific tables rather than
  181. all selected tables. It may be helpful particularly when
  182. :meth:`~.QuerySet.select_for_update()` is used in conjunction with
  183. :meth:`~.QuerySet.select_related()`.
  184. * The new ``field_name`` parameter of :meth:`.QuerySet.in_bulk` allows fetching
  185. results based on any unique model field.
  186. * :meth:`.CursorWrapper.callproc()` now takes an optional dictionary of keyword
  187. parameters, if the backend supports this feature. Of Django's built-in
  188. backends, only Oracle supports it.
  189. * The new ``filter`` argument for built-in aggregates allows :ref:`adding
  190. different conditionals <conditional-aggregation>` to multiple aggregations
  191. over the same fields or relations.
  192. Requests and Responses
  193. ~~~~~~~~~~~~~~~~~~~~~~
  194. * The :djadmin:`runserver` Web server supports HTTP 1.1.
  195. Serialization
  196. ~~~~~~~~~~~~~
  197. * ...
  198. Signals
  199. ~~~~~~~
  200. * ...
  201. Templates
  202. ~~~~~~~~~
  203. * To increase the usefulness of :meth:`.Engine.get_default` in third-party
  204. apps, it now returns the first engine if multiple ``DjangoTemplates`` engines
  205. are configured in ``TEMPLATES`` rather than raising ``ImproperlyConfigured``.
  206. * Custom template tags may now accept keyword-only arguments.
  207. Tests
  208. ~~~~~
  209. * Added threading support to :class:`~django.test.LiveServerTestCase`.
  210. * Added settings that allow customizing the test tablespace parameters for
  211. Oracle: :setting:`DATAFILE_SIZE`, :setting:`DATAFILE_TMP_SIZE`,
  212. :setting:`DATAFILE_EXTSIZE`, and :setting:`DATAFILE_TMP_EXTSIZE`.
  213. URLs
  214. ~~~~
  215. * ...
  216. Validators
  217. ~~~~~~~~~~
  218. * The new :class:`.ProhibitNullCharactersValidator` disallows the null
  219. character in the input of the :class:`~django.forms.CharField` form field
  220. and its subclasses. Null character input was observed from vulnerability
  221. scanning tools. Most databases silently discard null characters, but
  222. psycopg2 2.7+ raises an exception when trying to save a null character to
  223. a char/text field with PostgreSQL.
  224. .. _backwards-incompatible-2.0:
  225. Backwards incompatible changes in 2.0
  226. =====================================
  227. Removed support for bytestrings in some places
  228. ----------------------------------------------
  229. To support native Python 2 strings, older Django versions had to accept both
  230. bytestrings and unicode strings. Now that Python 2 support is dropped,
  231. bytestrings should only be encountered around input/output boundaries (handling
  232. of binary fields or HTTP streams, for example). You might have to update your
  233. code to limit bytestring usage to a minimum, as Django no longer accepts
  234. bytestrings in certain code paths.
  235. Database backend API
  236. --------------------
  237. This section describes changes that may be needed in third-party database
  238. backends.
  239. * The ``DatabaseOperations.datetime_cast_date_sql()``,
  240. ``datetime_cast_time_sql()``, ``datetime_trunc_sql()``,
  241. ``datetime_extract_sql()``, and ``date_interval_sql()`` methods now return
  242. only the SQL to perform the operation instead of SQL and a list of
  243. parameters.
  244. * Third-party database backends should add a ``DatabaseWrapper.display_name``
  245. attribute with the name of the database that your backend works with. Django
  246. may use it in various messages, such as in system checks.
  247. * The first argument of ``SchemaEditor._alter_column_type_sql()`` is now
  248. ``model`` rather than ``table``.
  249. * The first argument of ``SchemaEditor._create_index_name()`` is now
  250. ``table_name`` rather than ``model``.
  251. * To enable ``FOR UPDATE OF`` support, set
  252. ``DatabaseFeatures.has_select_for_update_of = True``. If the database
  253. requires that the arguments to ``OF`` be columns rather than tables, set
  254. ``DatabaseFeatures.select_for_update_of_column = True``.
  255. * Third-party database backends should add a
  256. ``DatabaseOperations.cast_char_field_without_max_length`` attribute with the
  257. database data type that will be used in the
  258. :class:`~django.db.models.functions.Cast` function for a ``CharField`` if the
  259. ``max_length`` argument isn't provided.
  260. Dropped support for Oracle 11.2
  261. -------------------------------
  262. The end of upstream support for Oracle 11.2 is Dec. 2020. Django 1.11 will be
  263. supported until April 2020 which almost reaches this date. Django 2.0
  264. officially supports Oracle 12.1+.
  265. Default MySQL isolation level is read committed
  266. -----------------------------------------------
  267. MySQL's default isolation level, repeatable read, may cause data loss in
  268. typical Django usage. To prevent that and for consistency with other databases,
  269. the default isolation level is now read committed. You can use the
  270. :setting:`DATABASES` setting to :ref:`use a different isolation level
  271. <mysql-isolation-level>`, if needed.
  272. :attr:`AbstractUser.last_name <django.contrib.auth.models.User.last_name>` ``max_length`` increased to 150
  273. ----------------------------------------------------------------------------------------------------------
  274. A migration for :attr:`django.contrib.auth.models.User.last_name` is included.
  275. If you have a custom user model inheriting from ``AbstractUser``, you'll need
  276. to generate and apply a database migration for your user model.
  277. If you want to preserve the 30 character limit for last names, use a custom
  278. form::
  279. from django.contrib.auth.forms import UserChangeForm
  280. class MyUserChangeForm(UserChangeForm):
  281. last_name = forms.CharField(max_length=30, required=False)
  282. If you wish to keep this restriction in the admin when editing users, set
  283. ``UserAdmin.form`` to use this form::
  284. from django.contrib.auth.admin import UserAdmin
  285. from django.contrib.auth.models import User
  286. class MyUserAdmin(UserAdmin):
  287. form = MyUserChangeForm
  288. admin.site.unregister(User)
  289. admin.site.register(User, MyUserAdmin)
  290. ``QuerySet.reverse()`` and ``last()`` are prohibited after slicing
  291. ------------------------------------------------------------------
  292. Calling ``QuerySet.reverse()`` or ``last()`` on a sliced queryset leads to
  293. unexpected results due to the slice being applied after reordering. This is
  294. now prohibited, e.g.::
  295. >>> Model.objects.all()[:2].reverse()
  296. Traceback (most recent call last):
  297. ...
  298. TypeError: Cannot reverse a query once a slice has been taken.
  299. Form fields no longer accept optional arguments as positional arguments
  300. -----------------------------------------------------------------------
  301. To help prevent runtime errors due to incorrect ordering of form field
  302. arguments, optional arguments of built-in form fields are no longer accepted
  303. as positional arguments. For example::
  304. forms.IntegerField(25, 10)
  305. raises an exception and should be replaced with::
  306. forms.IntegerField(max_value=25, min_value=10)
  307. ``call_command()`` validates the options it receives
  308. ----------------------------------------------------
  309. ``call_command()`` now validates that the argument parser of the command being
  310. called defines all of the options passed to ``call_command()``.
  311. For custom management commands that use options not created using
  312. ``parser.add_argument()``, add a ``stealth_options`` attribute on the command::
  313. class MyCommand(BaseCommand):
  314. stealth_options = ('option_name', ...)
  315. Indexes no longer accept positional arguments
  316. ---------------------------------------------
  317. For example::
  318. models.Index(['headline', '-pub_date'], 'index_name')
  319. raises an exception and should be replaced with::
  320. models.Index(fields=['headline', '-pub_date'], name='index_name')
  321. Foreign key constraints are now enabled on SQLite
  322. -------------------------------------------------
  323. This will appear as a backwards-incompatible change (``IntegrityError:
  324. FOREIGN KEY constraint failed``) if attempting to save an existing model
  325. instance that's violating a foreign key constraint.
  326. Foreign keys are now created with ``DEFERRABLE INITIALLY DEFERRED`` instead of
  327. ``DEFERRABLE IMMEDIATE``. Thus, tables may need to be rebuilt to recreate
  328. foreign keys with the new definition, particularly if you're using a pattern
  329. like this::
  330. from django.db import transaction
  331. with transaction.atomic():
  332. Book.objects.create(author_id=1)
  333. Author.objects.create(id=1)
  334. If you don't recreate the foreign key as ``DEFERRED``, the first ``create()``
  335. would fail now that foreign key constraints are enforced.
  336. Backup your database first! After upgrading to Django 2.0, you can then
  337. rebuild tables using a script similar to this::
  338. from django.apps import apps
  339. from django.db import connection
  340. for app in apps.get_app_configs():
  341. for model in app.get_models(include_auto_created=True):
  342. if model._meta.managed and not (model._meta.proxy or model._meta.swapped):
  343. for base in model.__bases__:
  344. if hasattr(base, '_meta'):
  345. base._meta.local_many_to_many = []
  346. model._meta.local_many_to_many = []
  347. with connection.schema_editor() as editor:
  348. editor._remake_table(model)
  349. This script hasn't received extensive testing and needs adaption for various
  350. cases such as multiple databases. Feel free to contribute improvements.
  351. Miscellaneous
  352. -------------
  353. * The ``SessionAuthenticationMiddleware`` class is removed. It provided no
  354. functionality since session authentication is unconditionally enabled in
  355. Django 1.10.
  356. * The default HTTP error handlers (``handler404``, etc.) are now callables
  357. instead of dotted Python path strings. Django favors callable references
  358. since they provide better performance and debugging experience.
  359. * :class:`~django.views.generic.base.RedirectView` no longer silences
  360. ``NoReverseMatch`` if the ``pattern_name`` doesn't exist.
  361. * When :setting:`USE_L10N` is off, :class:`~django.forms.FloatField` and
  362. :class:`~django.forms.DecimalField` now respect :setting:`DECIMAL_SEPARATOR`
  363. and :setting:`THOUSAND_SEPARATOR` during validation. For example, with the
  364. settings::
  365. USE_L10N = False
  366. USE_THOUSAND_SEPARATOR = True
  367. DECIMAL_SEPARATOR = ','
  368. THOUSAND_SEPARATOR = '.'
  369. an input of ``"1.345"`` is now converted to ``1345`` instead of ``1.345``.
  370. * Subclasses of :class:`~django.contrib.auth.models.AbstractBaseUser` are no
  371. longer required to implement ``get_short_name()`` and ``get_full_name()``.
  372. (The base implementations that raise ``NotImplementedError`` are removed.)
  373. ``django.contrib.admin`` uses these methods if implemented but doesn't
  374. require them. Third-party apps that use these methods may want to adopt a
  375. similar approach.
  376. * The ``FIRST_DAY_OF_WEEK`` and ``NUMBER_GROUPING`` format settings are now
  377. kept as integers in JavaScript and JSON i18n view outputs.
  378. * :meth:`~django.test.TransactionTestCase.assertNumQueries` now ignores
  379. connection configuration queries. Previously, if a test opened a new database
  380. connection, those queries could be included as part of the
  381. ``assertNumQueries()`` count.
  382. * The ``PASSWORD_RESET_TIMEOUT_DAYS`` setting is more properly respected in
  383. ``contrib.auth`` password reset. Previously, resets were allowed for one day
  384. longer than expected. For example, with the default of
  385. ``PASSWORD_RESET_TIMEOUT_DAYS = 3``, password reset tokens are now valid for
  386. 72 hours rather than 96 hours.
  387. * The default size of the Oracle test tablespace is increased from 20M to 50M
  388. and the default autoextend size is increased from 10M to 25M.
  389. * To improve performance when streaming large result sets from the database,
  390. :meth:`.QuerySet.iterator` now fetches 2000 rows at a time instead of 100.
  391. The old behavior can be restored using the ``chunk_size`` parameter. For
  392. example::
  393. Book.objects.iterator(chunk_size=100)
  394. * Providing unknown package names in the ``packages`` argument of the
  395. :class:`~django.views.i18n.JavaScriptCatalog` view now raises ``ValueError``
  396. instead of passing silently.
  397. * A model instance's primary key now appears in the default ``Model.__str__()``
  398. method, e.g. ``Question object (1)``.
  399. * ``makemigrations`` now detects changes to the model field ``limit_choices_to``
  400. option. Add this to your existing migrations or accept an auto-generated
  401. migration for fields that use it.
  402. * Performing queries that require :ref:`automatic spatial transformations
  403. <automatic-spatial-transformations>` now raises ``NotImplementedError``
  404. on MySQL instead of silently using non-transformed geometries.
  405. * ``django.core.exceptions.DjangoRuntimeWarning`` is removed. It was only used
  406. in the cache backend as an intermediate class in ``CacheKeyWarning``'s
  407. inheritance of ``RuntimeWarning``.
  408. * Renamed ``BaseExpression._output_field`` to ``output_field``. You may need
  409. to update custom expressions.
  410. * In older versions, forms and formsets combine their ``Media`` with widget
  411. ``Media`` by concatenating the two. The combining now tries to :ref:`preserve
  412. the relative order of elements in each list <form-media-asset-order>`.
  413. ``MediaOrderConflictWarning`` is issued if the order can't be preserved.
  414. .. _deprecated-features-2.0:
  415. Features deprecated in 2.0
  416. ==========================
  417. ``context`` argument of ``Field.from_db_value()`` and ``Expression.convert_value()``
  418. ------------------------------------------------------------------------------------
  419. The ``context`` argument of ``Field.from_db_value()`` and
  420. ``Expression.convert_value()`` is unused as it's always an empty dictionary.
  421. The signature of both methods is now::
  422. (self, value, expression, connection)
  423. instead of::
  424. (self, value, expression, connection, context)
  425. Support for the old signature in custom fields and expressions remains until
  426. Django 3.0.
  427. Miscellaneous
  428. -------------
  429. * The ``django.db.backends.postgresql_psycopg2`` module is deprecated in favor
  430. of ``django.db.backends.postgresql``. It's been an alias since Django 1.9.
  431. This only affects code that imports from the module directly. The
  432. ``DATABASES`` setting can still use
  433. ``'django.db.backends.postgresql_psycopg2'``, though you can simplify that by
  434. using the ``'django.db.backends.postgresql'`` name added in Django 1.9.
  435. * ``django.shortcuts.render_to_response()`` is deprecated in favor of
  436. :func:`django.shortcuts.render`. ``render()`` takes the same arguments
  437. except that is also requires a ``request``.
  438. * The ``DEFAULT_CONTENT_TYPE`` setting is deprecated. It doesn't interact well
  439. well with third-party apps and is obsolete since HTML5 has mostly superseded
  440. XHTML.
  441. * ``HttpRequest.xreadlines()`` is deprecated in favor of iterating over the
  442. request.
  443. .. _removed-features-2.0:
  444. Features removed in 2.0
  445. =======================
  446. These features have reached the end of their deprecation cycle and are removed
  447. in Django 2.0. See :ref:`deprecated-features-1.9` and
  448. :ref:`deprecated-features-1.10` for details, including how to remove usage of
  449. these features.
  450. * The ``weak`` argument to ``django.dispatch.signals.Signal.disconnect()`` is
  451. removed.
  452. * ``django.db.backends.base.BaseDatabaseOperations.check_aggregate_support()``
  453. is removed.
  454. * The ``django.forms.extras`` package is removed.
  455. * The ``assignment_tag`` helper is removed.
  456. * The ``host`` argument to ``SimpleTestCase.assertsRedirects()`` is removed.
  457. The compatibility layer which allows absolute URLs to be considered equal to
  458. relative ones when the path is identical is also removed.
  459. * ``Field.rel`` and ``Field.remote_field.to`` are removed.
  460. * The ``on_delete`` argument for ``ForeignKey`` and ``OneToOneField`` are now
  461. required.
  462. * ``django.db.models.fields.add_lazy_relation()`` is removed.
  463. * When time zone support is enabled, database backends that don't support time
  464. zones no longer convert aware datetimes to naive values in UTC anymore when
  465. such values are passed as parameters to SQL queries executed outside of the
  466. ORM, e.g. with ``cursor.execute()``.
  467. * ``django.contrib.auth.tests.utils.skipIfCustomUser()`` is removed.
  468. * The ``GeoManager`` and ``GeoQuerySet`` classes are removed.
  469. * The ``django.contrib.gis.geoip`` module is removed.
  470. * The ``supports_recursion`` check for template loaders is removed from:
  471. * ``django.template.engine.Engine.find_template()``
  472. * ``django.template.loader_tags.ExtendsNode.find_template()``
  473. * ``django.template.loaders.base.Loader.supports_recursion()``
  474. * ``django.template.loaders.cached.Loader.supports_recursion()``
  475. * The ``load_template`` and ``load_template_sources`` template loader methods
  476. are removed.
  477. * The ``template_dirs`` argument for template loaders is removed:
  478. * ``django.template.loaders.base.Loader.get_template()``
  479. * ``django.template.loaders.cached.Loader.cache_key()``
  480. * ``django.template.loaders.cached.Loader.get_template()``
  481. * ``django.template.loaders.cached.Loader.get_template_sources()``
  482. * ``django.template.loaders.filesystem.Loader.get_template_sources()``
  483. * ``django.template.loaders.base.Loader.__call__()`` is removed.
  484. * Support for custom error views that don't accept an ``exception`` parameter
  485. is removed.
  486. * The ``mime_type`` attribute of ``django.utils.feedgenerator.Atom1Feed`` and
  487. ``django.utils.feedgenerator.RssFeed`` is removed.
  488. * The ``app_name`` argument to ``include()`` is removed.
  489. * Support for passing a 3-tuple (including ``admin.site.urls``) as the first
  490. argument to ``include()`` is removed.
  491. * Support for setting a URL instance namespace without an application namespace
  492. is removed.
  493. * ``Field._get_val_from_obj()`` is removed.
  494. * ``django.template.loaders.eggs.Loader`` is removed.
  495. * The ``current_app`` parameter to the ``contrib.auth`` function-based views is
  496. removed.
  497. * The ``callable_obj`` keyword argument to
  498. ``SimpleTestCase.assertRaisesMessage()`` is removed.
  499. * Support for the ``allow_tags`` attribute on ``ModelAdmin`` methods is
  500. removed.
  501. * The ``enclosure`` keyword argument to ``SyndicationFeed.add_item()`` is
  502. removed.
  503. * The ``django.template.loader.LoaderOrigin`` and
  504. ``django.template.base.StringOrigin`` aliases for
  505. ``django.template.base.Origin`` are removed.
  506. * The ``makemigrations --exit`` option is removed.
  507. * Support for direct assignment to a reverse foreign key or many-to-many
  508. relation is removed.
  509. * The ``get_srid()`` and ``set_srid()`` methods of
  510. ``django.contrib.gis.geos.GEOSGeometry`` are removed.
  511. * The ``get_x()``, ``set_x()``, ``get_y()``, ``set_y()``, ``get_z()``, and
  512. ``set_z()`` methods of ``django.contrib.gis.geos.Point`` are removed.
  513. * The ``get_coords()`` and ``set_coords()`` methods of
  514. ``django.contrib.gis.geos.Point`` are removed.
  515. * The ``cascaded_union`` property of ``django.contrib.gis.geos.MultiPolygon``
  516. is removed.
  517. * ``django.utils.functional.allow_lazy()`` is removed.
  518. * The ``shell --plain`` option is removed.
  519. * The ``django.core.urlresolvers`` module is removed.
  520. * ``CommaSeparatedIntegerField`` is removed, except for support in historical
  521. migrations.
  522. * The template ``Context.has_key()`` method is removed.
  523. * Support for the ``django.core.files.storage.Storage.accessed_time()``,
  524. ``created_time()``, and ``modified_time()`` methods is removed.
  525. * Support for query lookups using the model name when
  526. ``Meta.default_related_name`` is set is removed.
  527. * The MySQL ``__search`` lookup is removed.
  528. * The shim for supporting custom related manager classes without a
  529. ``_apply_rel_filters()`` method is removed.
  530. * Using ``User.is_authenticated()`` and ``User.is_anonymous()`` as methods
  531. rather than properties is no longer supported.
  532. * The ``Model._meta.virtual_fields`` attribute is removed.
  533. * The keyword arguments ``virtual_only`` in ``Field.contribute_to_class()`` and
  534. ``virtual`` in ``Model._meta.add_field()`` are removed.
  535. * The ``javascript_catalog()`` and ``json_catalog()`` views are removed.
  536. * ``django.contrib.gis.utils.precision_wkt()`` is removed.
  537. * In multi-table inheritance, implicit promotion of a ``OneToOneField`` to a
  538. ``parent_link`` is removed.
  539. * Support for ``Widget._format_value()`` is removed.
  540. * ``FileField`` methods ``get_directory_name()`` and ``get_filename()`` are
  541. removed.
  542. * The ``mark_for_escaping()`` function and the classes it uses: ``EscapeData``,
  543. ``EscapeBytes``, ``EscapeText``, ``EscapeString``, and ``EscapeUnicode`` are
  544. removed.
  545. * The ``escape`` filter now uses ``django.utils.html.conditional_escape()``.
  546. * ``Manager.use_for_related_fields`` is removed.
  547. * Model ``Manager`` inheritance follows MRO inheritance rules. The requirement
  548. to use ``Meta.manager_inheritance_from_future`` to opt-in to the behavior is
  549. removed.
  550. * Support for old-style middleware using ``settings.MIDDLEWARE_CLASSES`` is
  551. removed.