1. ========================
    
  2. Django 1.5 release notes
    
  3. ========================
    
  4. 
    
  5. *February 26, 2013*
    
  6. 
    
  7. Welcome to Django 1.5!
    
  8. 
    
  9. These release notes cover the :ref:`new features <whats-new-1.5>`, as well as
    
  10. some :ref:`backwards incompatible changes <backwards-incompatible-1.5>` you'll
    
  11. want to be aware of when upgrading from Django 1.4 or older versions. We've
    
  12. also dropped some features, which are detailed in :ref:`our deprecation plan
    
  13. <deprecation-removed-in-1.5>`, and we've :ref:`begun the deprecation process
    
  14. for some features <deprecated-features-1.5>`.
    
  15. 
    
  16. Overview
    
  17. ========
    
  18. 
    
  19. The biggest new feature in Django 1.5 is the `configurable User model`_. Before
    
  20. Django 1.5, applications that wanted to use Django's auth framework
    
  21. (:mod:`django.contrib.auth`) were forced to use Django's definition of a "user".
    
  22. In Django 1.5, you can now swap out the ``User`` model for one that you write
    
  23. yourself. This could be a simple extension to the existing ``User`` model -- for
    
  24. example, you could add a Twitter or Facebook ID field -- or you could completely
    
  25. replace the ``User`` with one totally customized for your site.
    
  26. 
    
  27. Django 1.5 is also the first release with `Python 3 support`_! We're labeling
    
  28. this support "experimental" because we don't yet consider it production-ready,
    
  29. but everything's in place for you to start porting your apps to Python 3.
    
  30. Our next release, Django 1.6, will support Python 3 without reservations.
    
  31. 
    
  32. Other notable new features in Django 1.5 include:
    
  33. 
    
  34. * `Support for saving a subset of model's fields`_ -
    
  35.   :meth:`Model.save() <django.db.models.Model.save()>` now accepts an
    
  36.   ``update_fields`` argument, letting you specify which fields are
    
  37.   written back to the database when you call ``save()``. This can help
    
  38.   in high-concurrency operations, and can improve performance.
    
  39. 
    
  40. * Better `support for streaming responses <#explicit-streaming-responses>`_ via
    
  41.   the new  :class:`~django.http.StreamingHttpResponse` response class.
    
  42. 
    
  43. * `GeoDjango`_ now supports PostGIS 2.0.
    
  44. 
    
  45. * ... and more; `see below <#what-s-new-in-django-1-5>`_.
    
  46. 
    
  47. Wherever possible we try to introduce new features in a backwards-compatible
    
  48. manner per :doc:`our API stability policy </misc/api-stability>`.
    
  49. However, as with previous releases, Django 1.5 ships with some minor
    
  50. :ref:`backwards incompatible changes <backwards-incompatible-1.5>`; people
    
  51. upgrading from previous versions of Django should read that list carefully.
    
  52. 
    
  53. One deprecated feature worth noting is the shift to "new-style" :ttag:`url` tag.
    
  54. Prior to Django 1.3, syntax like ``{% url myview %}`` was interpreted
    
  55. incorrectly (Django considered ``"myview"`` to be a literal name of a view, not
    
  56. a template variable named ``myview``). Django 1.3 and above introduced the
    
  57. ``{% load url from future %}`` syntax to bring in the corrected behavior where
    
  58. ``myview`` was seen as a variable.
    
  59. 
    
  60. The upshot of this is that if you are not using ``{% load url from future %}``
    
  61. in your templates, you'll need to change tags like ``{% url myview %}`` to
    
  62. ``{% url "myview" %}``. If you *were* using ``{% load url from future %}`` you
    
  63. can simply remove that line under Django 1.5
    
  64. 
    
  65. Python compatibility
    
  66. ====================
    
  67. 
    
  68. Django 1.5 requires Python 2.6.5 or above, though we **highly recommend**
    
  69. Python 2.7.3 or above. Support for Python 2.5 and below has been dropped.
    
  70. 
    
  71. This change should affect only a small number of Django users, as most
    
  72. operating-system vendors today are shipping Python 2.6 or newer as their default
    
  73. version. If you're still using Python 2.5, however, you'll need to stick to
    
  74. Django 1.4 until you can upgrade your Python version. Per :doc:`our support
    
  75. policy </internals/release-process>`, Django 1.4 will continue to receive
    
  76. security support until the release of Django 1.6.
    
  77. 
    
  78. Django 1.5 does not run on a Jython final release, because Jython's latest
    
  79. release doesn't currently support Python 2.6. However, Jython currently does
    
  80. offer an alpha release featuring 2.7 support, and Django 1.5 supports that alpha
    
  81. release.
    
  82. 
    
  83. Python 3 support
    
  84. ----------------
    
  85. 
    
  86. Django 1.5 introduces support for Python 3 - specifically, Python
    
  87. 3.2 and above. This comes in the form of a **single** codebase; you don't
    
  88. need to install a different version of Django on Python 3. This means that
    
  89. you can write applications targeted for just Python 2, just Python 3, or single
    
  90. applications that support both platforms.
    
  91. 
    
  92. However, we're labeling this support "experimental" for now: although it's
    
  93. received extensive testing via our automated test suite, it's received very
    
  94. little real-world testing. We've done our best to eliminate bugs, but we can't
    
  95. be sure we covered all possible uses of Django.
    
  96. 
    
  97. Some features of Django aren't available because they depend on third-party
    
  98. software that hasn't been ported to Python 3 yet, including:
    
  99. 
    
  100. - the MySQL database backend (depends on MySQLdb)
    
  101. - :class:`~django.db.models.ImageField` (depends on PIL)
    
  102. - :class:`~django.test.LiveServerTestCase` (depends on Selenium WebDriver)
    
  103. 
    
  104. Further, Django's more than a web framework; it's an ecosystem of pluggable
    
  105. components. At this point, very few third-party applications have been ported
    
  106. to Python 3, so it's unlikely that a real-world application will have all its
    
  107. dependencies satisfied under Python 3.
    
  108. 
    
  109. Thus, we're recommending that Django 1.5 not be used in production under Python
    
  110. 3. Instead, use this opportunity to begin porting applications to Python 3. If
    
  111. you're an author of a pluggable component, we encourage you to start porting
    
  112. now.
    
  113. 
    
  114. We plan to offer first-class, production-ready support for Python 3 in our next
    
  115. release, Django 1.6.
    
  116. 
    
  117. .. _whats-new-1.5:
    
  118. 
    
  119. What's new in Django 1.5
    
  120. ========================
    
  121. 
    
  122. Configurable User model
    
  123. -----------------------
    
  124. 
    
  125. In Django 1.5, you can now use your own model as the store for user-related
    
  126. data. If your project needs a username with more than 30 characters, or if
    
  127. you want to store user's names in a format other than first name/last name,
    
  128. or you want to put custom profile information onto your User object, you can
    
  129. now do so.
    
  130. 
    
  131. If you have a third-party reusable application that references the User model,
    
  132. you may need to make some changes to the way you reference User instances. You
    
  133. should also document any specific features of the User model that your
    
  134. application relies upon.
    
  135. 
    
  136. See the :ref:`documentation on custom user models <auth-custom-user>` for
    
  137. more details.
    
  138. 
    
  139. Support for saving a subset of model's fields
    
  140. ---------------------------------------------
    
  141. 
    
  142. The method :meth:`Model.save() <django.db.models.Model.save()>` has a new
    
  143. keyword argument ``update_fields``. By using this argument it is possible to
    
  144. save only a select list of model's fields. This can be useful for performance
    
  145. reasons or when trying to avoid overwriting concurrent changes.
    
  146. 
    
  147. Deferred instances (those loaded by ``.only()`` or ``.defer()``) will
    
  148. automatically save just the loaded fields. If any field is set manually after
    
  149. load, that field will also get updated on save.
    
  150. 
    
  151. See the :meth:`Model.save() <django.db.models.Model.save()>` documentation for
    
  152. more details.
    
  153. 
    
  154. Caching of related model instances
    
  155. ----------------------------------
    
  156. 
    
  157. When traversing relations, the ORM will avoid re-fetching objects that were
    
  158. previously loaded. For example, with the tutorial's models::
    
  159. 
    
  160.     >>> first_poll = Poll.objects.all()[0]
    
  161.     >>> first_choice = first_poll.choice_set.all()[0]
    
  162.     >>> first_choice.poll is first_poll
    
  163.     True
    
  164. 
    
  165. In Django 1.5, the third line no longer triggers a new SQL query to fetch
    
  166. ``first_choice.poll``; it was set by the second line.
    
  167. 
    
  168. For one-to-one relationships, both sides can be cached. For many-to-one
    
  169. relationships, only the single side of the relationship can be cached. This
    
  170. is particularly helpful in combination with ``prefetch_related``.
    
  171. 
    
  172. .. _explicit-streaming-responses:
    
  173. 
    
  174. Explicit support for streaming responses
    
  175. ----------------------------------------
    
  176. 
    
  177. Before Django 1.5, it was possible to create a streaming response by passing
    
  178. an iterator to :class:`~django.http.HttpResponse`. But this was unreliable:
    
  179. any middleware that accessed the :attr:`~django.http.HttpResponse.content`
    
  180. attribute would consume the iterator prematurely.
    
  181. 
    
  182. You can now explicitly generate a streaming response with the new
    
  183. :class:`~django.http.StreamingHttpResponse` class. This class exposes a
    
  184. :class:`~django.http.StreamingHttpResponse.streaming_content` attribute which
    
  185. is an iterator.
    
  186. 
    
  187. Since :class:`~django.http.StreamingHttpResponse` does not have a ``content``
    
  188. attribute, middleware that needs access to the response content must test for
    
  189. streaming responses and behave accordingly.
    
  190. 
    
  191. ``{% verbatim %}`` template tag
    
  192. -------------------------------
    
  193. 
    
  194. To make it easier to deal with JavaScript templates which collide with Django's
    
  195. syntax, you can now use the :ttag:`verbatim` block tag to avoid parsing the
    
  196. tag's content.
    
  197. 
    
  198. Retrieval of ``ContentType`` instances associated with proxy models
    
  199. -------------------------------------------------------------------
    
  200. 
    
  201. The methods :meth:`ContentTypeManager.get_for_model() <django.contrib.contenttypes.models.ContentTypeManager.get_for_model()>`
    
  202. and :meth:`ContentTypeManager.get_for_models() <django.contrib.contenttypes.models.ContentTypeManager.get_for_models()>`
    
  203. have a new keyword argument – respectively ``for_concrete_model`` and ``for_concrete_models``.
    
  204. By passing ``False`` using this argument it is now possible to retrieve the
    
  205. :class:`ContentType <django.contrib.contenttypes.models.ContentType>`
    
  206. associated with proxy models.
    
  207. 
    
  208. New ``view`` variable in class-based views context
    
  209. --------------------------------------------------
    
  210. 
    
  211. In all :doc:`generic class-based views </topics/class-based-views/index>`
    
  212. (or any class-based view inheriting from ``ContextMixin``), the context dictionary
    
  213. contains a ``view`` variable that points to the ``View`` instance.
    
  214. 
    
  215. GeoDjango
    
  216. ---------
    
  217. 
    
  218. * :class:`~django.contrib.gis.geos.LineString` and
    
  219.   :class:`~django.contrib.gis.geos.MultiLineString` GEOS objects now support the
    
  220.   :meth:`~django.contrib.gis.geos.GEOSGeometry.interpolate()` and
    
  221.   :meth:`~django.contrib.gis.geos.GEOSGeometry.project()` methods
    
  222.   (so-called linear referencing).
    
  223. 
    
  224. * The ``wkb`` and ``hex`` properties of
    
  225.   :class:`~django.contrib.gis.geos.GEOSGeometry` objects preserve the Z
    
  226.   dimension.
    
  227. 
    
  228. * Support for PostGIS 2.0 has been added and support for GDAL < 1.5 has been
    
  229.   dropped.
    
  230. 
    
  231. New tutorials
    
  232. -------------
    
  233. 
    
  234. Additions to the docs include a revamped :doc:`Tutorial 3</intro/tutorial03>`
    
  235. and a new :doc:`tutorial on testing</intro/tutorial05>`. A new section,
    
  236. "Advanced Tutorials", offers :doc:`How to write reusable apps
    
  237. </intro/reusable-apps>` as well as a step-by-step guide for new contributors in
    
  238. :doc:`Writing your first patch for Django </intro/contributing>`.
    
  239. 
    
  240. Minor features
    
  241. --------------
    
  242. 
    
  243. Django 1.5 also includes several smaller improvements worth noting:
    
  244. 
    
  245. * The template engine now interprets ``True``, ``False`` and ``None`` as the
    
  246.   corresponding Python objects.
    
  247. 
    
  248. * :mod:`django.utils.timezone` provides a helper for converting aware
    
  249.   datetimes between time zones. See :func:`~django.utils.timezone.localtime`.
    
  250. 
    
  251. * The generic views support OPTIONS requests.
    
  252. 
    
  253. * Management commands do not raise ``SystemExit`` any more when called by code
    
  254.   from :func:`~django.core.management.call_command`. Any exception raised by
    
  255.   the command (mostly :exc:`~django.core.management.CommandError`) is
    
  256.   propagated.
    
  257. 
    
  258.   Moreover, when you output errors or messages in your custom commands, you
    
  259.   should now use ``self.stdout.write('message')`` and
    
  260.   ``self.stderr.write('error')`` (see the note on
    
  261.   :ref:`management commands output <management-commands-output>`).
    
  262. 
    
  263. * The :djadmin:`dumpdata` management command outputs one row at a time,
    
  264.   preventing out-of-memory errors when dumping large datasets.
    
  265. 
    
  266. * In the localflavor for Canada, ``pq`` was added to the acceptable codes for
    
  267.   Quebec. It's an old abbreviation.
    
  268. 
    
  269. * The :ref:`receiver <connecting-receiver-functions>` decorator is now able to
    
  270.   connect to more than one signal by supplying a list of signals.
    
  271. 
    
  272. * In the admin, you can now filter users by groups which they are members of.
    
  273. 
    
  274. * :meth:`QuerySet.bulk_create()
    
  275.   <django.db.models.query.QuerySet.bulk_create>` now has a batch_size
    
  276.   argument. By default the batch_size is unlimited except for SQLite where
    
  277.   single batch is limited so that 999 parameters per query isn't exceeded.
    
  278. 
    
  279. * The :setting:`LOGIN_URL` and :setting:`LOGIN_REDIRECT_URL` settings now also
    
  280.   accept view function names and
    
  281.   :ref:`named URL patterns <naming-url-patterns>`. This allows you to reduce
    
  282.   configuration duplication. More information can be found in the
    
  283.   :func:`~django.contrib.auth.decorators.login_required` documentation.
    
  284. 
    
  285. * Django now provides a mod_wsgi :doc:`auth handler
    
  286.   </howto/deployment/wsgi/apache-auth>`.
    
  287. 
    
  288. * The :meth:`QuerySet.delete() <django.db.models.query.QuerySet.delete>`
    
  289.   and :meth:`Model.delete() <django.db.models.Model.delete()>` can now take
    
  290.   fast-path in some cases. The fast-path allows for less queries and less
    
  291.   objects fetched into memory. See :meth:`QuerySet.delete()
    
  292.   <django.db.models.query.QuerySet.delete>` for details.
    
  293. 
    
  294. * An instance of ``ResolverMatch`` is stored on the request as
    
  295.   ``resolver_match``.
    
  296. 
    
  297. * By default, all logging messages reaching the ``django`` logger when
    
  298.   :setting:`DEBUG` is ``True`` are sent to the console (unless you redefine the
    
  299.   logger in your :setting:`LOGGING` setting).
    
  300. 
    
  301. * When using :class:`~django.template.RequestContext`, it is now possible to
    
  302.   look up permissions by using ``{% if 'someapp.someperm' in perms %}``
    
  303.   in templates.
    
  304. 
    
  305. * It's not required any more to have ``404.html`` and ``500.html`` templates in
    
  306.   the root templates directory. Django will output some basic error messages for
    
  307.   both situations when those templates are not found. It's still recommended as
    
  308.   good practice to provide those templates in order to present pretty error
    
  309.   pages to the user.
    
  310. 
    
  311. * :mod:`django.contrib.auth` provides a new signal that is emitted
    
  312.   whenever a user fails to login successfully. See
    
  313.   :data:`~django.contrib.auth.signals.user_login_failed`
    
  314. 
    
  315. * The new :option:`loaddata --ignorenonexistent` option ignore data for fields
    
  316.   that no longer exist.
    
  317. 
    
  318. * :meth:`~django.test.SimpleTestCase.assertXMLEqual` and
    
  319.   :meth:`~django.test.SimpleTestCase.assertXMLNotEqual` new assertions allow
    
  320.   you to test equality for XML content at a semantic level, without caring for
    
  321.   syntax differences (spaces, attribute order, etc.).
    
  322. 
    
  323. * RemoteUserMiddleware now forces logout when the REMOTE_USER header
    
  324.   disappears during the same browser session.
    
  325. 
    
  326. * The :ref:`cache-based session backend <cached-sessions-backend>` can store
    
  327.   session data in a non-default cache.
    
  328. 
    
  329. * Multi-column indexes can now be created on models. Read the
    
  330.   :attr:`~django.db.models.Options.index_together` documentation for more
    
  331.   information.
    
  332. 
    
  333. * During Django's logging configuration verbose Deprecation warnings are
    
  334.   enabled and warnings are captured into the logging system. Logged warnings
    
  335.   are routed through the ``console`` logging handler, which by default requires
    
  336.   :setting:`DEBUG` to be True for output to be generated. The result is that
    
  337.   DeprecationWarnings should be printed to the console in development
    
  338.   environments the way they have been in Python versions < 2.7.
    
  339. 
    
  340. * The API for :meth:`django.contrib.admin.ModelAdmin.message_user` method has
    
  341.   been modified to accept additional arguments adding capabilities similar to
    
  342.   :func:`django.contrib.messages.add_message`. This is useful for generating
    
  343.   error messages from admin actions.
    
  344. 
    
  345. * The admin's list filters can now be customized per-request thanks to the new
    
  346.   :meth:`django.contrib.admin.ModelAdmin.get_list_filter` method.
    
  347. 
    
  348. .. _backwards-incompatible-1.5:
    
  349. 
    
  350. Backwards incompatible changes in 1.5
    
  351. =====================================
    
  352. 
    
  353. .. warning::
    
  354. 
    
  355.     In addition to the changes outlined in this section, be sure to review the
    
  356.     :ref:`deprecation plan <deprecation-removed-in-1.5>` for any features that
    
  357.     have been removed. If you haven't updated your code within the
    
  358.     deprecation timeline for a given feature, its removal may appear as a
    
  359.     backwards incompatible change.
    
  360. 
    
  361. ``ALLOWED_HOSTS`` required in production
    
  362. ----------------------------------------
    
  363. 
    
  364. The new :setting:`ALLOWED_HOSTS` setting validates the request's ``Host``
    
  365. header and protects against host-poisoning attacks. This setting is now
    
  366. required whenever :setting:`DEBUG` is ``False``, or else
    
  367. :meth:`django.http.HttpRequest.get_host()` will raise
    
  368. :exc:`~django.core.exceptions.SuspiciousOperation`. For more details see the
    
  369. :setting:`full documentation<ALLOWED_HOSTS>` for the new setting.
    
  370. 
    
  371. Managers on abstract models
    
  372. ---------------------------
    
  373. 
    
  374. Abstract models are able to define a custom manager, and that manager
    
  375. :ref:`will be inherited by any concrete models extending the abstract model
    
  376. <custom-managers-and-inheritance>`. However, if you try to use the abstract
    
  377. model to call a method on the manager, an exception will now be raised.
    
  378. Previously, the call would have been permitted, but would have failed as soon
    
  379. as any database operation was attempted (usually with a "table does not exist"
    
  380. error from the database).
    
  381. 
    
  382. If you have functionality on a manager that you have been invoking using
    
  383. the abstract class, you should migrate that logic to a Python
    
  384. ``staticmethod`` or ``classmethod`` on the abstract class.
    
  385. 
    
  386. Context in year archive class-based views
    
  387. -----------------------------------------
    
  388. 
    
  389. For consistency with the other date-based generic views,
    
  390. :class:`~django.views.generic.dates.YearArchiveView` now passes ``year`` in
    
  391. the context as a :class:`datetime.date` rather than a string.  If you are
    
  392. using ``{{ year }}`` in your templates, you must replace it with ``{{
    
  393. year|date:"Y" }}``.
    
  394. 
    
  395. ``next_year`` and ``previous_year`` were also added in the context. They are
    
  396. calculated according to ``allow_empty`` and ``allow_future``.
    
  397. 
    
  398. Context in year and month archive class-based views
    
  399. ---------------------------------------------------
    
  400. 
    
  401. :class:`~django.views.generic.dates.YearArchiveView` and
    
  402. :class:`~django.views.generic.dates.MonthArchiveView` were documented to
    
  403. provide a ``date_list`` sorted in ascending order in the context, like their
    
  404. function-based predecessors, but it actually was in descending order. In 1.5,
    
  405. the documented order was restored. You may want to add (or remove) the
    
  406. ``reversed`` keyword when you're iterating on ``date_list`` in a template::
    
  407. 
    
  408.     {% for date in date_list reversed %}
    
  409. 
    
  410. :class:`~django.views.generic.dates.ArchiveIndexView` still provides a
    
  411. ``date_list`` in descending order.
    
  412. 
    
  413. Context in TemplateView
    
  414. -----------------------
    
  415. 
    
  416. For consistency with the design of the other generic views,
    
  417. :class:`~django.views.generic.base.TemplateView` no longer passes a ``params``
    
  418. dictionary into the context, instead passing the variables from the URLconf
    
  419. directly into the context.
    
  420. 
    
  421. Non-form data in HTTP requests
    
  422. ------------------------------
    
  423. 
    
  424. :attr:`request.POST <django.http.HttpRequest.POST>` will no longer include data
    
  425. posted via HTTP requests with non form-specific content-types in the header.
    
  426. In prior versions, data posted with content-types other than
    
  427. :mimetype:`multipart/form-data` or
    
  428. :mimetype:`application/x-www-form-urlencoded` would still end up represented in
    
  429. the :attr:`request.POST <django.http.HttpRequest.POST>` attribute. Developers
    
  430. wishing to access the raw POST data for these cases, should use the
    
  431. :attr:`request.body <django.http.HttpRequest.body>` attribute instead.
    
  432. 
    
  433. :data:`~django.core.signals.request_finished` signal
    
  434. ----------------------------------------------------
    
  435. 
    
  436. Django used to send the :data:`~django.core.signals.request_finished` signal
    
  437. as soon as the view function returned a response. This interacted badly with
    
  438. :ref:`streaming responses <httpresponse-streaming>` that delay content
    
  439. generation.
    
  440. 
    
  441. This signal is now sent after the content is fully consumed by the WSGI
    
  442. gateway. This might be backwards incompatible if you rely on the signal being
    
  443. fired before sending the response content to the client. If you do, you should
    
  444. consider using :doc:`middleware </topics/http/middleware>` instead.
    
  445. 
    
  446. .. note::
    
  447. 
    
  448.     Some WSGI servers and middleware do not always call ``close`` on the
    
  449.     response object after handling a request, most notably uWSGI prior to 1.2.6
    
  450.     and Sentry's error reporting middleware up to 2.0.7. In those cases the
    
  451.     ``request_finished`` signal isn't sent at all. This can result in idle
    
  452.     connections to database and memcache servers.
    
  453. 
    
  454. OPTIONS, PUT and DELETE requests in the test client
    
  455. ---------------------------------------------------
    
  456. 
    
  457. Unlike GET and POST, these HTTP methods aren't implemented by web browsers.
    
  458. Rather, they're used in APIs, which transfer data in various formats such as
    
  459. JSON or XML. Since such requests may contain arbitrary data, Django doesn't
    
  460. attempt to decode their body.
    
  461. 
    
  462. However, the test client used to build a query string for OPTIONS and DELETE
    
  463. requests like for GET, and a request body for PUT requests like for POST. This
    
  464. encoding was arbitrary and inconsistent with Django's behavior when it
    
  465. receives the requests, so it was removed in Django 1.5.
    
  466. 
    
  467. If you were using the ``data`` parameter in an OPTIONS or a DELETE request,
    
  468. you must convert it to a query string and append it to the ``path`` parameter.
    
  469. 
    
  470. If you were using the ``data`` parameter in a PUT request without a
    
  471. ``content_type``, you must encode your data before passing it to the test
    
  472. client and set the ``content_type`` argument.
    
  473. 
    
  474. .. _simplejson-incompatibilities:
    
  475. 
    
  476. System version of ``simplejson`` no longer used
    
  477. -----------------------------------------------
    
  478. 
    
  479. :ref:`As explained below <simplejson-deprecation>`, Django 1.5 deprecates
    
  480. ``django.utils.simplejson`` in favor of Python 2.6's built-in :mod:`json`
    
  481. module. In theory, this change is harmless. Unfortunately, because of
    
  482. incompatibilities between versions of ``simplejson``, it may trigger errors
    
  483. in some circumstances.
    
  484. 
    
  485. JSON-related features in Django 1.4 always used ``django.utils.simplejson``.
    
  486. This module was actually:
    
  487. 
    
  488. - A system version of ``simplejson``, if one was available (i.e. ``import
    
  489.   simplejson`` works), if it was more recent than Django's built-in copy or it
    
  490.   had the C speedups, or
    
  491. - The :mod:`json` module from the standard library, if it was available (i.e.
    
  492.   Python 2.6 or greater), or
    
  493. - A built-in copy of version 2.0.7 of ``simplejson``.
    
  494. 
    
  495. In Django 1.5, those features use Python's :mod:`json` module, which is based
    
  496. on version 2.0.9 of ``simplejson``.
    
  497. 
    
  498. There are no known incompatibilities between Django's copy of version 2.0.7 and
    
  499. Python's copy of version 2.0.9. However, there are some incompatibilities
    
  500. between other versions of ``simplejson``:
    
  501. 
    
  502. - While the ``simplejson`` API is documented as always returning Unicode
    
  503.   strings, the optional C implementation can return a bytestring. This was
    
  504.   fixed in Python 2.7.
    
  505. - ``simplejson.JSONEncoder`` gained a ``namedtuple_as_object`` keyword
    
  506.   argument in version 2.2.
    
  507. 
    
  508. More information on these incompatibilities is available in
    
  509. :ticket:`ticket #18023 <18023#comment:10>`.
    
  510. 
    
  511. The net result is that, if you have installed ``simplejson`` and your code
    
  512. uses Django's serialization internals directly -- for instance
    
  513. ``django.core.serializers.json.DjangoJSONEncoder``, the switch from
    
  514. ``simplejson`` to :mod:`json` could break your code. (In general, changes to
    
  515. internals aren't documented; we're making an exception here.)
    
  516. 
    
  517. At this point, the maintainers of Django believe that using :mod:`json` from
    
  518. the standard library offers the strongest guarantee of backwards-compatibility.
    
  519. They recommend to use it from now on.
    
  520. 
    
  521. String types of hasher method parameters
    
  522. ----------------------------------------
    
  523. 
    
  524. If you have written a :ref:`custom password hasher <auth_password_storage>`,
    
  525. your ``encode()``, ``verify()`` or ``safe_summary()`` methods should accept
    
  526. Unicode parameters (``password``, ``salt`` or ``encoded``). If any of the
    
  527. hashing methods need bytestrings, you can use the
    
  528. :func:`~django.utils.encoding.force_bytes` utility to encode the strings.
    
  529. 
    
  530. Validation of previous_page_number and next_page_number
    
  531. -------------------------------------------------------
    
  532. 
    
  533. When using :doc:`object pagination </topics/pagination>`,
    
  534. the ``previous_page_number()`` and ``next_page_number()`` methods of the
    
  535. :class:`~django.core.paginator.Page` object did not check if the returned
    
  536. number was inside the existing page range.
    
  537. It does check it now and raises an :exc:`~django.core.paginator.InvalidPage`
    
  538. exception when the number is either too low or too high.
    
  539. 
    
  540. Behavior of autocommit database option on PostgreSQL changed
    
  541. ------------------------------------------------------------
    
  542. 
    
  543. PostgreSQL's autocommit option didn't work as advertised previously. It did
    
  544. work for single transaction block, but after the first block was left the
    
  545. autocommit behavior was never restored. This bug is now fixed in 1.5. While
    
  546. this is only a bug fix, it is worth checking your applications behavior if
    
  547. you are using PostgreSQL together with the autocommit option.
    
  548. 
    
  549. Session not saved on 500 responses
    
  550. ----------------------------------
    
  551. 
    
  552. Django's session middleware will skip saving the session data if the
    
  553. response's status code is 500.
    
  554. 
    
  555. Email checks on failed admin login
    
  556. ----------------------------------
    
  557. 
    
  558. Prior to Django 1.5, if you attempted to log into the admin interface and
    
  559. mistakenly used your email address instead of your username, the admin
    
  560. interface would provide a warning advising that your email address was
    
  561. not your username. In Django 1.5, the introduction of
    
  562. :ref:`custom user models <auth-custom-user>` has required the removal of this
    
  563. warning. This doesn't change the login behavior of the admin site; it only
    
  564. affects the warning message that is displayed under one particular mode of
    
  565. login failure.
    
  566. 
    
  567. Changes in tests execution
    
  568. --------------------------
    
  569. 
    
  570. Some changes have been introduced in the execution of tests that might be
    
  571. backward-incompatible for some testing setups:
    
  572. 
    
  573. Database flushing in ``django.test.TransactionTestCase``
    
  574. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    
  575. 
    
  576. Previously, the test database was truncated *before* each test run in a
    
  577. :class:`~django.test.TransactionTestCase`.
    
  578. 
    
  579. In order to be able to run unit tests in any order and to make sure they are
    
  580. always isolated from each other, :class:`~django.test.TransactionTestCase` will
    
  581. now reset the database *after* each test run instead.
    
  582. 
    
  583. No more implicit DB sequences reset
    
  584. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    
  585. 
    
  586. :class:`~django.test.TransactionTestCase` tests used to reset primary key
    
  587. sequences automatically together with the database flushing actions described
    
  588. above.
    
  589. 
    
  590. This has been changed so no sequences are implicitly reset. This can cause
    
  591. :class:`~django.test.TransactionTestCase` tests that depend on hard-coded
    
  592. primary key values to break.
    
  593. 
    
  594. The new :attr:`~django.test.TransactionTestCase.reset_sequences` attribute can
    
  595. be used to force the old behavior for :class:`~django.test.TransactionTestCase`
    
  596. that might need it.
    
  597. 
    
  598. Ordering of tests
    
  599. ~~~~~~~~~~~~~~~~~
    
  600. 
    
  601. In order to make sure all ``TestCase`` code starts with a clean database,
    
  602. tests are now executed in the following order:
    
  603. 
    
  604. * First, all unit tests (including :class:`unittest.TestCase`,
    
  605.   :class:`~django.test.SimpleTestCase`, :class:`~django.test.TestCase` and
    
  606.   :class:`~django.test.TransactionTestCase`) are run with no particular ordering
    
  607.   guaranteed nor enforced among them.
    
  608. 
    
  609. * Then any other tests (e.g. doctests) that may alter the database without
    
  610.   restoring it to its original state are run.
    
  611. 
    
  612. This should not cause any problems unless you have existing doctests which
    
  613. assume a :class:`~django.test.TransactionTestCase` executed earlier left some
    
  614. database state behind or unit tests that rely on some form of state being
    
  615. preserved after the execution of other tests. Such tests are already very
    
  616. fragile, and must now be changed to be able to run independently.
    
  617. 
    
  618. ``cleaned_data`` dictionary kept for invalid forms
    
  619. --------------------------------------------------
    
  620. 
    
  621. The :attr:`~django.forms.Form.cleaned_data` dictionary is now always present
    
  622. after form validation. When the form doesn't validate, it contains only the
    
  623. fields that passed validation. You should test the success of the validation
    
  624. with the :meth:`~django.forms.Form.is_valid()` method and not with the
    
  625. presence or absence of the :attr:`~django.forms.Form.cleaned_data` attribute
    
  626. on the form.
    
  627. 
    
  628. Behavior of ``syncdb`` with multiple databases
    
  629. ----------------------------------------------
    
  630. 
    
  631. ``syncdb`` now queries the database routers to determine if content
    
  632. types (when :mod:`~django.contrib.contenttypes` is enabled) and permissions
    
  633. (when :mod:`~django.contrib.auth` is enabled) should be created in the target
    
  634. database. Previously, it created them in the default database, even when
    
  635. another database was specified with the ``--database`` option.
    
  636. 
    
  637. If you use ``syncdb`` on multiple databases, you should ensure that
    
  638. your routers allow synchronizing content types and permissions to only one of
    
  639. them. See the docs on the :ref:`behavior of contrib apps with multiple
    
  640. databases <contrib_app_multiple_databases>` for more information.
    
  641. 
    
  642. XML deserializer will not parse documents with a DTD
    
  643. ----------------------------------------------------
    
  644. 
    
  645. In order to prevent exposure to denial-of-service attacks related to external
    
  646. entity references and entity expansion, the XML model deserializer now refuses
    
  647. to parse XML documents containing a DTD (DOCTYPE definition). Since the XML
    
  648. serializer does not output a DTD, this will not impact typical usage, only
    
  649. cases where custom-created XML documents are passed to Django's model
    
  650. deserializer.
    
  651. 
    
  652. Formsets default ``max_num``
    
  653. ----------------------------
    
  654. 
    
  655. A (default) value of ``None`` for the ``max_num`` argument to a formset factory
    
  656. no longer defaults to allowing any number of forms in the formset. Instead, in
    
  657. order to prevent memory-exhaustion attacks, it now defaults to a limit of 1000
    
  658. forms. This limit can be raised by explicitly setting a higher value for
    
  659. ``max_num``.
    
  660. 
    
  661. Miscellaneous
    
  662. -------------
    
  663. 
    
  664. * :class:`django.forms.ModelMultipleChoiceField` now returns an empty
    
  665.   ``QuerySet`` as the empty value instead of an empty list.
    
  666. 
    
  667. * :func:`~django.utils.http.int_to_base36` properly raises a
    
  668.   :exc:`TypeError` instead of :exc:`ValueError` for non-integer inputs.
    
  669. 
    
  670. * The ``slugify`` template filter is now available as a standard Python
    
  671.   function at :func:`django.utils.text.slugify`. Similarly, ``remove_tags`` is
    
  672.   available at ``django.utils.html.remove_tags()``.
    
  673. 
    
  674. * Uploaded files are no longer created as executable by default. If you need
    
  675.   them to be executable change :setting:`FILE_UPLOAD_PERMISSIONS` to your
    
  676.   needs. The new default value is ``0o666`` (octal) and the current umask value
    
  677.   is first masked out.
    
  678. 
    
  679. * The :class:`F expressions <django.db.models.F>` supported bitwise operators by
    
  680.   ``&`` and ``|``. These operators are now available using ``.bitand()`` and
    
  681.   ``.bitor()`` instead. The removal of ``&`` and ``|`` was done to be
    
  682.   consistent with :ref:`Q() expressions <complex-lookups-with-q>` and
    
  683.   ``QuerySet`` combining where the operators are used as boolean AND and OR
    
  684.   operators.
    
  685. 
    
  686. * In a ``filter()`` call, when :class:`F expressions <django.db.models.F>`
    
  687.   contained lookups spanning multi-valued relations, they didn't always reuse
    
  688.   the same relations as other lookups along the same chain. This was changed,
    
  689.   and now F() expressions will always use the same relations as other lookups
    
  690.   within the same ``filter()`` call.
    
  691. 
    
  692. * The :ttag:`csrf_token` template tag is no longer enclosed in a div. If you need
    
  693.   HTML validation against pre-HTML5 Strict DTDs, you should add a div around it
    
  694.   in your pages.
    
  695. 
    
  696. * The template tags library ``adminmedia``, which only contained the
    
  697.   deprecated template tag ``{% admin_media_prefix %}``, was removed.
    
  698.   Attempting to load it with ``{% load adminmedia %}`` will fail. If your
    
  699.   templates still contain that line you must remove it.
    
  700. 
    
  701. * Because of an implementation oversight, it was possible to use
    
  702.   :doc:`django.contrib.redirects </ref/contrib/redirects>` without enabling
    
  703.   :doc:`django.contrib.sites </ref/contrib/sites>`. This isn't allowed any
    
  704.   longer. If you're using ``django.contrib.redirects``, make sure
    
  705.   :setting:`INSTALLED_APPS` contains ``django.contrib.sites``.
    
  706. 
    
  707. * :meth:`BoundField.label_tag <django.forms.BoundField.label_tag>` now
    
  708.   escapes its ``contents`` argument. To avoid the HTML escaping, use
    
  709.   :func:`django.utils.safestring.mark_safe` on the argument before passing it.
    
  710. 
    
  711. * Accessing reverse one-to-one relations fetched via
    
  712.   :meth:`~django.db.models.query.QuerySet.select_related` now raises
    
  713.   :exc:`~django.db.models.Model.DoesNotExist` instead of returning ``None``.
    
  714. 
    
  715. .. _deprecated-features-1.5:
    
  716. 
    
  717. Features deprecated in 1.5
    
  718. ==========================
    
  719. 
    
  720. ``django.contrib.localflavor``
    
  721. ------------------------------
    
  722. 
    
  723. The localflavor contrib app has been split into separate packages.
    
  724. ``django.contrib.localflavor`` itself will be removed in Django 1.6,
    
  725. after an accelerated deprecation.
    
  726. 
    
  727. The new packages are available on GitHub. The core team cannot
    
  728. efficiently maintain these packages in the long term — it spans just a
    
  729. dozen countries at this time; similar to translations, maintenance
    
  730. will be handed over to interested members of the community.
    
  731. 
    
  732. ``django.contrib.markup``
    
  733. -------------------------
    
  734. 
    
  735. The markup contrib module has been deprecated and will follow an accelerated
    
  736. deprecation schedule. Direct use of Python markup libraries or 3rd party tag
    
  737. libraries is preferred to Django maintaining this functionality in the
    
  738. framework.
    
  739. 
    
  740. ``AUTH_PROFILE_MODULE``
    
  741. -----------------------
    
  742. 
    
  743. With the introduction of :ref:`custom user models <auth-custom-user>`, there is
    
  744. no longer any need for a built-in mechanism to store user profile data.
    
  745. 
    
  746. You can still define user profiles models that have a one-to-one relation with
    
  747. the User model - in fact, for many applications needing to associate data with
    
  748. a User account, this will be an appropriate design pattern to follow. However,
    
  749. the ``AUTH_PROFILE_MODULE`` setting, and the
    
  750. ``django.contrib.auth.models.User.get_profile()`` method for accessing
    
  751. the user profile model, should not be used any longer.
    
  752. 
    
  753. Streaming behavior of :class:`~django.http.HttpResponse`
    
  754. --------------------------------------------------------
    
  755. 
    
  756. Django 1.5 deprecates the ability to stream a response by passing an iterator
    
  757. to :class:`~django.http.HttpResponse`. If you rely on this behavior, switch to
    
  758. :class:`~django.http.StreamingHttpResponse`. See
    
  759. :ref:`explicit-streaming-responses` above.
    
  760. 
    
  761. In Django 1.7 and above, the iterator will be consumed immediately by
    
  762. :class:`~django.http.HttpResponse`.
    
  763. 
    
  764. .. _simplejson-deprecation:
    
  765. 
    
  766. ``django.utils.simplejson``
    
  767. ---------------------------
    
  768. 
    
  769. Since Django 1.5 drops support for Python 2.5, we can now rely on the
    
  770. :mod:`json` module being available in Python's standard library, so we've
    
  771. removed our own copy of ``simplejson``. You should now import :mod:`json`
    
  772. instead of ``django.utils.simplejson``.
    
  773. 
    
  774. Unfortunately, this change might have unwanted side-effects, because of
    
  775. incompatibilities between versions of ``simplejson`` -- see the
    
  776. :ref:`backwards-incompatible changes <simplejson-incompatibilities>` section.
    
  777. If you rely on features added to ``simplejson`` after it became Python's
    
  778. :mod:`json`, you should import ``simplejson`` explicitly.
    
  779. 
    
  780. ``django.utils.encoding.StrAndUnicode``
    
  781. ---------------------------------------
    
  782. 
    
  783. The ``django.utils.encoding.StrAndUnicode`` mix-in has been deprecated.
    
  784. Define a ``__str__`` method and apply the
    
  785. ``django.utils.encoding.python_2_unicode_compatible`` decorator instead.
    
  786. 
    
  787. ``django.utils.itercompat.product``
    
  788. -----------------------------------
    
  789. 
    
  790. The ``django.utils.itercompat.product`` function has been deprecated. Use
    
  791. the built-in :func:`itertools.product` instead.
    
  792. 
    
  793. ``cleanup`` management command
    
  794. ------------------------------
    
  795. 
    
  796. The ``cleanup`` management command has been deprecated and replaced by
    
  797. :djadmin:`clearsessions`.
    
  798. 
    
  799. ``daily_cleanup.py`` script
    
  800. ---------------------------
    
  801. 
    
  802. The undocumented ``daily_cleanup.py`` script has been deprecated. Use the
    
  803. :djadmin:`clearsessions` management command instead.
    
  804. 
    
  805. ``depth`` keyword argument in ``select_related``
    
  806. ------------------------------------------------
    
  807. 
    
  808. The ``depth`` keyword argument in
    
  809. :meth:`~django.db.models.query.QuerySet.select_related` has been deprecated.
    
  810. You should use field names instead.