summaryrefslogtreecommitdiff
path: root/docs/releases/1.8.txt
blob: 0200e18d48ebbd31a6b38aa20cfb3b829eb64239 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
============================================
Django 1.8 release notes - UNDER DEVELOPMENT
============================================

Welcome to Django 1.8!

These release notes cover the `new features`_, as well as some `backwards
incompatible changes`_ you'll want to be aware of when upgrading from Django
1.7 or older versions. We've also `begun the deprecation process for some
features`_, and some features have reached the end of their deprecation process
and `have been removed`_.

Django 1.8 has been designated as Django's second :ref:`"Long-Term Support"
(LTS) <lts-releases>` release. It will receive security updates for at least
three years after its release. Support for the previous LTS, Django 1.4, will
end 6 months from the release date of Django 1.8.

.. _`new features`: `What's new in Django 1.8`_
.. _`backwards incompatible changes`: `Backwards incompatible changes in 1.8`_
.. _`begun the deprecation process for some features`: `Features deprecated in 1.8`_
.. _`have been removed`: `Features removed in 1.8`_

Python compatibility
====================

Like Django 1.7, Django 1.8 requires Python 2.7 or above, though we
**highly recommend** the latest minor release.

What's new in Django 1.8
========================

``Model._meta`` API
~~~~~~~~~~~~~~~~~~~

Django now has a formalized API for :doc:`Model._meta </ref/models/meta>`,
providing an officially supported way to :ref:`retrieve fields
<model-meta-field-api>` and filter fields based on their :ref:`attributes
<model-field-attributes>`.

The ``Model._meta`` object has been part of Django since the days of pre-0.96
"Magic Removal" -- it just wasn't an official, stable API. In recognition of
this, we've endeavored to maintain backwards-compatibility with the old
API endpoint where possible. However, API endpoints that aren't part of the
new official API have been deprecated and will eventually be removed. A
:ref:`guide to migrating from the old API to the new API
<migrating-old-meta-api>` has been provided.

Multiple template engines
~~~~~~~~~~~~~~~~~~~~~~~~~

Django 1.8 defines a stable API for integrating template backends. It includes
built-in support for the Django template language and for Jinja2_. It supports
rendering templates with multiple engines within the same project. Learn more
about the new features in the :doc:`topic guide </topics/templates>` and check
the :doc:`upgrade instructions </ref/templates/upgrading>` for details.

.. _Jinja2: http://jinja.pocoo.org/

Security enhancements
~~~~~~~~~~~~~~~~~~~~~

Several features of the django-secure_ third-party library have been
integrated into Django. :class:`django.middleware.security.SecurityMiddleware`
provides several security enhancements to the request/response cycle. The new
:djadminopt:`--deploy` option of the :djadmin:`check` command allows you to
check your production settings file for ways to increase the security of your
site.

.. _django-secure: https://pypi.python.org/pypi/django-secure

New PostgreSQL specific functionality
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Django now has a module with extensions for PostgreSQL specific features, such
as :class:`~django.contrib.postgres.fields.ArrayField`,
:class:`~django.contrib.postgres.fields.HStoreField`, :ref:`range-fields`, and
:lookup:`unaccent` lookup. A full breakdown of the features is available
:doc:`in the documentation </ref/contrib/postgres/index>`.

New data types
~~~~~~~~~~~~~~

* Django now has a :class:`~django.db.models.UUIDField` for storing
  universally unique identifiers. It is stored as the native ``uuid`` data type
  on PostgreSQL and as a fixed length character field on other backends. There
  is a corresponding :class:`form field <django.forms.UUIDField>`.

* Django now has a :class:`~django.db.models.DurationField` for storing periods
  of time - modeled in Python by :class:`~python:datetime.timedelta`. It is
  stored in the native ``interval`` data type on PostgreSQL, as a ``INTERVAL
  DAY(9) TO SECOND(6)`` on Oracle, and as a ``bigint`` of microseconds on other
  backends. Date and time related arithmetic has also been improved on all
  backends. There is a corresponding :class:`form field
  <django.forms.DurationField>`.

Query Expressions, Conditional Expressions, and Database Functions
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

:doc:`Query Expressions </ref/models/expressions>` allow you to create,
customize, and compose complex SQL expressions. This has enabled annotate
to accept expressions other than aggregates. Aggregates are now able to
reference multiple fields, as well as perform arithmetic, similar to ``F()``
objects. :meth:`~django.db.models.query.QuerySet.order_by` has also gained the
ability to accept expressions.

:doc:`Conditional Expressions </ref/models/conditional-expressions>` allow
you to use :keyword:`if` ... :keyword:`elif` ... :keyword:`else` logic within
queries.

A collection of :doc:`database functions </ref/models/database-functions>` is
also included with functionality such as
:class:`~django.db.models.functions.Coalesce`,
:class:`~django.db.models.functions.Concat`, and
:class:`~django.db.models.functions.Substr`.

``TestCase`` data setup
~~~~~~~~~~~~~~~~~~~~~~~

:class:`~django.test.TestCase` has been refactored to allow for data
initialization at the class level using transactions and savepoints. Database
backends which do not support transactions, like MySQL with the MyISAM storage
engine, will still be able to run these tests but won't benefit from the
improvements. Tests are now run within two nested
:func:`~django.db.transaction.atomic()` blocks: one for the whole class and one
for each test.

* The class method
  :meth:`TestCase.setUpTestData() <django.test.TestCase.setUpTestData>` adds
  the ability to setup test data at the class level. Using this technique can
  speed up the tests as compared to using ``setUp()``.

* Fixture loading within ``TestCase`` is now performed once for the whole
  ``TestCase``.

Minor features
~~~~~~~~~~~~~~

:mod:`django.contrib.admin`
^^^^^^^^^^^^^^^^^^^^^^^^^^^

* :class:`~django.contrib.admin.ModelAdmin` now has a
  :meth:`~django.contrib.admin.ModelAdmin.has_module_permission`
  method to allow limiting access to the module on the admin index page.

* :class:`~django.contrib.admin.InlineModelAdmin` now has an attribute
  :attr:`~django.contrib.admin.InlineModelAdmin.show_change_link` that
  supports showing a link to an inline object's change form.

* Use the new ``django.contrib.admin.RelatedOnlyFieldListFilter`` in
  :attr:`ModelAdmin.list_filter <django.contrib.admin.ModelAdmin.list_filter>`
  to limit the ``list_filter`` choices to foreign objects which are attached to
  those from the ``ModelAdmin``.

* The :meth:`ModelAdmin.delete_view()
  <django.contrib.admin.ModelAdmin.delete_view>` displays a summary of objects
  to be deleted on the deletion confirmation page.

* The jQuery library embedded in the admin has been upgraded to version 1.11.2.

* You can now specify :attr:`AdminSite.site_url
  <django.contrib.admin.AdminSite.site_url>` in order to display a link to the
  front-end site.

* You can now specify :attr:`ModelAdmin.show_full_result_count
  <django.contrib.admin.ModelAdmin.show_full_result_count>` to control whether
  or not the full count of objects should be displayed on a filtered admin page.

* The ``AdminSite.password_change()`` method now has an ``extra_context``
  parameter.

* You can now control who may login to the admin site by overriding only
  :meth:`AdminSite.has_permission()
  <django.contrib.admin.AdminSite.has_permission>` and
  :attr:`AdminSite.login_form <django.contrib.admin.AdminSite.login_form>`.
  The ``base.html`` template has a new block ``usertools`` which contains the
  user-specific header. A new context variable ``has_permission``, which gets
  its value from :meth:`~django.contrib.admin.AdminSite.has_permission`,
  indicates whether the user may access the site.

* Foreign key dropdowns now have buttons for changing or deleting related
  objects using a popup.

:mod:`django.contrib.admindocs`
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

* reStructuredText is now parsed in model docstrings.

:mod:`django.contrib.auth`
^^^^^^^^^^^^^^^^^^^^^^^^^^

* Authorization backends can now raise
  :class:`~django.core.exceptions.PermissionDenied` in
  :meth:`~django.contrib.auth.models.User.has_perm`
  and :meth:`~django.contrib.auth.models.User.has_module_perms`
  to short-circuit permission checking.
* :class:`~django.contrib.auth.forms.PasswordResetForm` now
  has a method :meth:`~django.contrib.auth.forms.PasswordResetForm.send_email`
  that can be overridden to customize the mail to be sent.

* The ``max_length`` of :attr:`Permission.name
  <django.contrib.auth.models.Permission.name>` has been increased from 50 to
  255 characters. Please run the database migration.

* :attr:`~django.contrib.auth.models.CustomUser.USERNAME_FIELD` and
  :attr:`~django.contrib.auth.models.CustomUser.REQUIRED_FIELDS` now supports
  :class:`~django.db.models.ForeignKey`\s.

* The default iteration count for the PBKDF2 password hasher has been
  increased by 33%. This backwards compatible change will not affect users who
  have subclassed ``django.contrib.auth.hashers.PBKDF2PasswordHasher`` to
  change the default value.

:mod:`django.contrib.gis`
^^^^^^^^^^^^^^^^^^^^^^^^^^

* A new :doc:`GeoJSON serializer </ref/contrib/gis/serializers>` is now
  available.

* It is now allowed to include a subquery as a geographic lookup argument, for
  example ``City.objects.filter(point__within=Country.objects.filter(continent='Africa').values('mpoly'))``.

* The Spatialite backend now supports ``Collect`` and ``Extent`` aggregates
  when the database version is 3.0 or later.

* The PostGIS 2 ``CREATE EXTENSION postgis`` and the Spatialite
  ``SELECT InitSpatialMetaData`` initialization commands are now automatically
  run by :djadmin:`migrate`.

* The GDAL interface now supports retrieving properties of
  :ref:`raster (image) data file <raster-data-source-objects>`.

* Compatibility shims for ``SpatialRefSys`` and ``GeometryColumns`` changed in
  Django 1.2 have been removed.

* All GDAL-related exceptions are now raised with ``GDALException``. The former
  ``OGRException`` has been kept for backwards compatibility but should not be
  used any longer.

:mod:`django.contrib.sessions`
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

* Session cookie is now deleted after
  :meth:`~django.contrib.sessions.backends.base.SessionBase.flush()` is called.

:mod:`django.contrib.sitemaps`
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

* The new :attr:`Sitemap.i18n <django.contrib.sitemaps.Sitemap.i18n>` attribute
  allows you to generate a sitemap based on the :setting:`LANGUAGES` setting.

:mod:`django.contrib.sites`
^^^^^^^^^^^^^^^^^^^^^^^^^^^

* :func:`~django.contrib.sites.shortcuts.get_current_site` will now lookup
  the current site based on :meth:`request.get_host()
  <django.http.HttpRequest.get_host>` if the :setting:`SITE_ID` setting is not
  defined.

* The default :class:`~django.contrib.sites.models.Site` created when running
  ``migrate`` now respects the :setting:`SITE_ID` setting (instead of always
  using ``pk=1``).

Cache
^^^^^

* The ``incr()`` method of the
  ``django.core.cache.backends.locmem.LocMemCache`` backend is now thread-safe.

Cryptography
^^^^^^^^^^^^

* The ``max_age`` parameter of the
  :meth:`django.core.signing.TimestampSigner.unsign` method now also accept a
  :py:class:`datetime.timedelta` object.

Database backends
^^^^^^^^^^^^^^^^^

* The MySQL backend no longer strips microseconds from ``datetime`` values as
  MySQL 5.6.4 and up supports fractional seconds depending on the declaration
  of the datetime field (when ``DATETIME`` includes fractional precision greater
  than 0). New datetime database columns created with Django 1.8 and MySQL 5.6.4
  and up will support microseconds. See the :ref:`MySQL database notes
  <mysql-fractional-seconds>` for more details.

* The MySQL backend no longer creates explicit indexes for foreign keys when
  using the InnoDB storage engine, as MySQL already creates them automatically.

* The Oracle backend no longer defines the ``connection_persists_old_columns``
  feature as ``True``. Instead, Oracle will now include a cache busting clause
  when getting the description of a table.

Email
^^^^^

* :ref:`Email backends <topic-email-backends>` now support the context manager
  protocol for opening and closing connections.

* The SMTP email backend now supports ``keyfile`` and ``certfile``
  authentication with the :setting:`EMAIL_SSL_CERTFILE` and
  :setting:`EMAIL_SSL_KEYFILE` settings.

* The SMTP :class:`~django.core.mail.backends.smtp.EmailBackend` now supports
  setting the ``timeout`` parameter with the :setting:`EMAIL_TIMEOUT` setting.

* :class:`~django.core.mail.EmailMessage` and ``EmailMultiAlternatives`` now
  support the ``reply_to`` parameter.

File Storage
^^^^^^^^^^^^

* :meth:`Storage.get_available_name()
  <django.core.files.storage.Storage.get_available_name>` and
  :meth:`Storage.save() <django.core.files.storage.Storage.save>`
  now take a ``max_length`` argument to implement storage-level maximum
  filename length constraints. Filenames exceeding this argument will get
  truncated. This prevents a database error when appending a unique suffix to a
  long filename that already exists on the storage. See the :ref:`deprecation
  note <storage-max-length-update>` about adding this argument to your custom
  storage classes.

Forms
^^^^^

* Form widgets now render attributes with a value of ``True`` or ``False``
  as HTML5 boolean attributes.

* The new :meth:`~django.forms.Form.has_error()` method allows checking
  if a specific error has happened.

* If :attr:`~django.forms.Form.required_css_class` is defined on a form, then
  the ``<label>`` tags for required fields will have this class present in its
  attributes.

* The rendering of non-field errors in unordered lists (``<ul>``) now includes
  ``nonfield`` in its list of classes to distinguish them from field-specific
  errors.

* :class:`~django.forms.Field` now accepts a
  :attr:`~django.forms.Field.label_suffix` argument, which will override the
  form's :attr:`~django.forms.Form.label_suffix`. This enables customizing the
  suffix on a per-field basis — previously it wasn't possible to override
  a form's :attr:`~django.forms.Form.label_suffix` while using  shortcuts such
  as ``{{ form.as_p }}`` in templates.

* :class:`~django.forms.SelectDateWidget` now accepts an
  :attr:`~django.forms.SelectDateWidget.empty_label` argument, which will
  override the top list choice label when :class:`~django.forms.DateField`
  is not required.

* After an :class:`~django.forms.ImageField` has been cleaned and validated, the
  ``UploadedFile`` object will have an additional ``image`` attribute containing
  the Pillow ``Image`` instance used to check if the file was a valid image. It
  will also update ``UploadedFile.content_type`` with the image's content type
  as determined by Pillow.

* You can now pass a callable that returns an iterable of choices when
  instantiating a :class:`~django.forms.ChoiceField`.

Generic Views
^^^^^^^^^^^^^

* Generic views that use :class:`~django.views.generic.list.MultipleObjectMixin`
  may now specify the ordering applied to the
  :attr:`~django.views.generic.list.MultipleObjectMixin.queryset` by setting
  :attr:`~django.views.generic.list.MultipleObjectMixin.ordering` or overriding
  :meth:`~django.views.generic.list.MultipleObjectMixin.get_ordering()`.

* The new :attr:`SingleObjectMixin.query_pk_and_slug
  <django.views.generic.detail.SingleObjectMixin.query_pk_and_slug>`
  attribute allows changing the behavior of
  :meth:`~django.views.generic.detail.SingleObjectMixin.get_object()`
  so that it'll perform its lookup using both the primary key and the slug.

* The :meth:`~django.views.generic.edit.FormMixin.get_form()` method doesn't
  require a ``form_class`` to be provided anymore. If not provided ``form_class``
  defaults to :meth:`~django.views.generic.edit.FormMixin.get_form_class()`.

* Placeholders in :attr:`ModelFormMixin.success_url
  <django.views.generic.edit.ModelFormMixin.success_url>` now support the Python
  :py:meth:`str.format()` syntax. The legacy ``%(<foo>)s`` syntax is still
  supported but will be removed in Django 2.0.

Internationalization
^^^^^^^^^^^^^^^^^^^^

* :setting:`FORMAT_MODULE_PATH` can now be a list of strings representing
  module paths. This allows importing several format modules from different
  reusable apps. It also allows overriding those custom formats in your main
  Django project.

Logging
^^^^^^^

* The :class:`django.utils.log.AdminEmailHandler` class now has a
  :meth:`~django.utils.log.AdminEmailHandler.send_mail` method to make it more
  subclass friendly.

Management Commands
^^^^^^^^^^^^^^^^^^^

* Database connections are now always closed after a management command called
  from the command line has finished doing its job.

* Commands from alternate package formats like eggs are now also discovered.

* :djadmin:`dumpdata` now has the option :djadminopt:`--output` which allows
  specifying the file to which the serialized data is written.

* :djadmin:`makemessages` and :djadmin:`compilemessages` now have the option
  :djadminopt:`--exclude` which allows exclusion of specific locales from
  processing.

* :djadmin:`compilemessages` now has a ``--use-fuzzy`` or ``-f`` option which
  includes fuzzy translations into compiled files.

* The :djadminopt:`--ignorenonexistent` option of the :djadmin:`loaddata`
  management command now ignores data for models that no longer exist.

* :djadmin:`runserver` now uses daemon threads for faster reloading.

* :djadmin:`inspectdb` now outputs ``Meta.unique_together``. It is also able to
  introspect :class:`~django.db.models.AutoField` for MySQL and PostgreSQL
  databases.

* :djadmin:`inspectdb` now introspects database views on all database backends.
  In previous versions, only tables (not views) were inspected.

* When calling management commands from code through :ref:`call_command
  <call-command>` and passing options, the option name can match the command
  line option name (without the initial dashes) or the final option destination
  variable name, but in either case, the resulting option received by the
  command is now always the ``dest`` name specified in the command option
  definition (as long as the command uses the new :py:mod:`argparse` module).

* The :djadmin:`dbshell` command now supports MySQL's optional SSL certificate
  authority setting (``--ssl-ca``).

* The :djadminopt:`--name` option for :djadmin:`makemigrations` allows you to
  to give the migration(s) a custom name instead of a generated one.

* The :djadmin:`loaddata` command now prevents repeated fixture loading. If
  :setting:`FIXTURE_DIRS` contains duplicates or a default fixture directory
  path (``app_name/fixtures``), an exception is raised.

* :djadmin:`makemigrations` now supports an :djadminopt:`--exit` option to
  exit with an error code if no migrations are created.

* The new :djadmin:`showmigrations` command allows listing all migrations and
  their dependencies in a project.

Middleware
^^^^^^^^^^

* The :attr:`CommonMiddleware.response_redirect_class
  <django.middleware.common.CommonMiddleware.response_redirect_class>`
  attribute allows you to customize the redirects issued by the middleware.

* A debug message will be logged to the ``django.request`` logger when a
  middleware raises a :exc:`~django.core.exceptions.MiddlewareNotUsed` exception
  in :setting:`DEBUG` mode.

Migrations
^^^^^^^^^^

* The :class:`~django.db.migrations.operations.RunSQL` operation can now handle
  parameters passed to the SQL statements.

* It is now possible to have migrations (most probably :ref:`data migrations
  <data-migrations>`) for applications without models.

* Migrations can now :ref:`serialize model managers
  <using-managers-in-migrations>` as part of the model state.

* A :ref:`generic mechanism to handle the deprecation of model fields
  <migrations-removing-model-fields>` was added.

* The :meth:`RunPython.noop() <django.db.migrations.operations.RunPython.noop>`
  and :attr:`RunSQL.noop <django.db.migrations.operations.RunSQL.noop>` class
  method/attribute were added to ease in making ``RunPython`` and ``RunSQL``
  operations reversible.

* The :class:`~django.db.migrations.operations.RunPython` and
  :class:`~django.db.migrations.operations.RunSQL` operations now accept a
  ``hints`` parameter that will be passed to :meth:`allow_migrate`. To take
  advantage of this feature you must ensure that the ``allow_migrate()`` method
  of all your routers accept ``**hints``.

Models
^^^^^^

* Django now logs at most 9000 queries in ``connections.queries``, in order
  to prevent excessive memory usage in long-running processes in debug mode.

* There is now a model ``Meta`` option to define a
  :attr:`default related name <django.db.models.Options.default_related_name>`
  for all relational fields of a model.

* Pickling models and querysets across different versions of Django isn't
  officially supported (it may work, but there's no guarantee). An extra
  variable that specifies the current Django version is now added to the
  pickled state of models and querysets, and Django raises a ``RuntimeWarning``
  when these objects are unpickled in a different version than the one in
  which they were pickled.

* Added :meth:`Model.from_db() <django.db.models.Model.from_db()>` which
  Django uses whenever objects are loaded using the ORM. The method allows
  customizing model loading behavior.

* ``extra(select={...})`` now allows you to escape a literal ``%s`` sequence
  using ``%%s``.

* :doc:`Custom Lookups</howto/custom-lookups>` can now be registered using
  a decorator pattern.

* The new :attr:`Transform.bilateral <django.db.models.Transform.bilateral>`
  attribute allows creating bilateral transformations. These transformations
  are applied to both ``lhs`` and ``rhs`` when used in a lookup expression,
  providing opportunities for more sophisticated lookups.

* SQL special characters (\, %, _) are now escaped properly when a pattern
  lookup (e.g. ``contains``, ``startswith``, etc.) is used with an ``F()``
  expression as the right-hand side. In those cases, the escaping is performed
  by the database, which can lead to somewhat complex queries involving nested
  ``REPLACE`` function calls.

* You can now refresh model instances by using :meth:`Model.refresh_from_db()
  <django.db.models.Model.refresh_from_db>`.

* You can now get the set of deferred fields for a model using
  :meth:`Model.get_deferred_fields() <django.db.models.Model.get_deferred_fields>`.

* Model field ``default``’s are now used when primary key field's are set to
  ``None``.

Signals
^^^^^^^

* Exceptions from the ``(receiver, exception)`` tuples returned by
  :meth:`Signal.send_robust() <django.dispatch.Signal.send_robust>` now have
  their traceback attached as a ``__traceback__`` attribute.

* The ``environ`` argument, which contains the WSGI environment structure from
  the request, was added to the :data:`~django.core.signals.request_started`
  signal.

* You can now import the :func:`~django.test.signals.setting_changed` signal
  from ``django.core.signals`` to avoid loading ``django.test`` in non-test
  situations. Django no longer does so itself.

System Check Framework
^^^^^^^^^^^^^^^^^^^^^^

* :attr:`~django.core.checks.register` can now be used as a function.

Templates
^^^^^^^^^

* :tfilter:`urlize` now supports domain-only links that include characters after
  the top-level domain (e.g. ``djangoproject.com/`` and
  ``djangoproject.com/download/``).

* :tfilter:`urlize` doesn't treat exclamation marks at the end of a domain or
  its query string as part of the URL (the URL in e.g. ``'djangoproject.com!``
  is ``djangoproject.com``)

* Added a :class:`locmem.Loader <django.template.loaders.locmem.Loader>`
  class that loads Django templates from a Python dictionary.

* The :ttag:`now` tag can now store its output in a context variable with the
  usual syntax: ``{% now 'j n Y' as varname %}``.

Requests and Responses
^^^^^^^^^^^^^^^^^^^^^^

* ``WSGIRequest`` now respects paths starting with ``//``.

* The :meth:`HttpRequest.build_absolute_uri()
  <django.http.HttpRequest.build_absolute_uri>` method now handles paths
  starting with ``//`` correctly.

* If :setting:`DEBUG` is ``True`` and a request raises a
  :exc:`~django.core.exceptions.SuspiciousOperation`, the response will be
  rendered with a detailed error page.

* The ``query_string`` argument of :class:`~django.http.QueryDict` is now
  optional, defaulting to ``None``, so a blank ``QueryDict`` can now be
  instantiated with ``QueryDict()`` instead of ``QueryDict(None)`` or
  ``QueryDict('')``.

* The ``GET`` and ``POST`` attributes of an :class:`~django.http.HttpRequest`
  object are now :class:`~django.http.QueryDict`\s rather than dictionaries,
  and the ``FILES`` attribute is now a ``MultiValueDict``.
  This brings this class into line with the documentation and with
  ``WSGIRequest``.

* The :attr:`HttpResponse.charset <django.http.HttpResponse.charset>` attribute
  was added.

* ``WSGIRequestHandler`` now follows RFC in converting URI to IRI, using
  ``uri_to_iri()``.

* The :meth:`HttpRequest.get_full_path()
  <django.http.HttpRequest.get_full_path>` method now escapes unsafe characters
  from the path portion of a Uniform Resource Identifier (URI) properly.

* :class:`~django.http.HttpResponse` now implements a few additional methods
  like :meth:`~django.http.HttpResponse.getvalue` so that instances can be used
  as stream objects.

* The new :meth:`HttpResponse.setdefault()
  <django.http.HttpResponse.setdefault>` method allows setting a header unless
  it has already been set.

* You can use the new :class:`~django.http.FileResponse` to stream files.

* The :func:`~django.views.decorators.http.condition` decorator for
  conditional view processing now supports the ``If-unmodified-since`` header.

Tests
^^^^^

* The :class:`RequestFactory.trace() <django.test.RequestFactory>`
  and :class:`Client.trace() <django.test.Client.trace>` methods were
  implemented, allowing you to create ``TRACE`` requests in your tests.

* The ``count`` argument was added to
  :meth:`~django.test.SimpleTestCase.assertTemplateUsed`. This allows you to
  assert that a template was rendered a specific number of times.

* The new :meth:`~django.test.SimpleTestCase.assertJSONNotEqual` assertion
  allows you to test that two JSON fragments are not equal.

* Added options to the :djadmin:`test` command to preserve the test database
  (:djadminopt:`--keepdb`), to run the test cases in reverse order
  (:djadminopt:`--reverse`), and to enable SQL logging for failing tests
  (:djadminopt:`--debug-sql`).

* Added the :attr:`~django.test.Response.resolver_match` attribute to test
  client responses.

* Added several settings that allow customization of test tablespace parameters
  for Oracle: :setting:`DATAFILE`, :setting:`DATAFILE_TMP`,
  :setting:`DATAFILE_MAXSIZE` and :setting:`DATAFILE_TMP_MAXSIZE`.

* The :func:`~django.test.override_settings` decorator can now affect the
  master router in :setting:`DATABASE_ROUTERS`.

* Added test client support for file uploads with file-like objects.

* A shared cache is now used when testing with a SQLite in-memory database when
  using Python 3.4+ and SQLite 3.7.13+. This allows sharing the database
  between threads.

Validators
^^^^^^^^^^

* :class:`~django.core.validators.URLValidator` now supports IPv6 addresses,
  unicode domains, and URLs containing authentication data.

Backwards incompatible changes in 1.8
=====================================

.. warning::

    In addition to the changes outlined in this section, be sure to review the
    :ref:`deprecation plan <deprecation-removed-in-1.8>` for any features that
    have 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.

Related object operations are run in a transaction
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Some operations on related objects such as
:meth:`~django.db.models.fields.related.RelatedManager.add()` or
:ref:`direct assignment<direct-assignment>` ran multiple data modifying
queries without wrapping them in transactions. To reduce the risk of data
corruption, all data modifying methods that affect multiple related objects
(i.e. ``add()``, ``remove()``, ``clear()``, and :ref:`direct assignment
<direct-assignment>`) now perform their data modifying queries from within a
transaction, provided your database supports transactions.

This has one backwards incompatible side effect, signal handlers triggered from
these methods are now executed within the method's transaction and any
exception in a signal handler will prevent the whole operation.

Assigning unsaved objects to relations raises an error
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Assigning unsaved objects to a :class:`~django.db.models.ForeignKey`,
:class:`~django.contrib.contenttypes.fields.GenericForeignKey`, and
:class:`~django.db.models.OneToOneField` now raises a :exc:`ValueError`.

Previously, the assignment of an unsaved object would be silently ignored.
For example::

    >>> book = Book.objects.create(name="Django")
    >>> book.author = Author(name="John")
    >>> book.author.save()
    >>> book.save()

    >>> Book.objects.get(name="Django")
    >>> book.author
    >>>

Now, an error will be raised to prevent data loss::

    >>> book.author = Author(name="john")
    Traceback (most recent call last):
    ...
    ValueError: Cannot assign "<Author: John>": "Author" instance isn't saved in the database.

Accessing foreign keys in ``ModelForm.save()``
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

In older versions, you could access unsaved foreign key objects in
``ModelForm.save()`` when adding new objects. For example, given ``Book`` with
a ``ForeignKey`` to ``Author``::

    class BookForm(forms.ModelForm):
        def save(self, *args, **kwargs):
            book = super(BookForm, self).save(*args, **kwargs)
            book.title = "%s by %s" % (book.title, book.author.name)
            return book

Now if the related instance hasn't been saved (for example, when adding an
author and some inlined books in the admin), accessing the foreign key
``book.author`` in the example) will raise ``RelatedObjectDoesNotExist``. This
change was necessary to avoid assigning unsaved objects to relations (as
described in the previous section).

To adapt the example above, you could replace ``book.author.name`` with
``self.cleaned_data['author'].name``.

Management commands that only accept positional arguments
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

If you have written a custom management command that only accepts positional
arguments and you didn't specify the
:attr:`~django.core.management.BaseCommand.args` command variable, you might
get an error like ``Error: unrecognized arguments: ...``, as variable parsing
is now based on :py:mod:`argparse` which doesn't implicitly accept positional
arguments. You can make your command backwards compatible by simply setting the
:attr:`~django.core.management.BaseCommand.args` class variable. However, if
you don't have to keep compatibility with older Django versions, it's better to
implement the new :meth:`~django.core.management.BaseCommand.add_arguments`
method as described in :doc:`/howto/custom-management-commands`.

Custom test management command arguments through test runner
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

The method to add custom arguments to the `test` management command through the
test runner has changed. Previously, you could provide an `option_list` class
variable on the test runner to add more arguments (à la :py:mod:`optparse`).
Now to implement the same behavior, you have to create an
``add_arguments(cls, parser)`` class method on the test runner and call
``parser.add_argument`` to add any custom arguments, as parser is now an
:py:class:`argparse.ArgumentParser` instance.

Model check ensures auto-generated column names are within limits specified by database
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

A field name that's longer than the column name length supported by a database
can create problems. For example, with MySQL you'll get an exception trying to
create the column, and with PostgreSQL the column name is truncated by the
database (you may see a warning in the PostgreSQL logs).

A model check has been introduced to better alert users to this scenario before
the actual creation of database tables.

If you have an existing model where this check seems to be a false positive,
for example on PostgreSQL where the name was already being truncated, simply
use :attr:`~django.db.models.Field.db_column` to specify the name that's being
used.

The check also applies to the columns generated in an implicit
``ManyToManyField.through`` model. If you run into an issue there, use
:attr:`~django.db.models.ManyToManyField.through` to create an explicit model
and then specify :attr:`~django.db.models.Field.db_column` on its column(s)
as needed.

Query relation lookups now check object types
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Querying for model lookups now checks if the object passed is of correct type
and raises a :exc:`ValueError` if not. Previously, Django didn't care if the
object was of correct type; it just used the object's related field attribute
(e.g. ``id``) for the lookup. Now, an error is raised to prevent incorrect
lookups::

    >>> book = Book.objects.create(name="Django")
    >>> book = Book.objects.filter(author=book)
    Traceback (most recent call last):
    ...
    ValueError: Cannot query "<Book: Django>": Must be "Author" instance.

``select_related()`` now checks given fields
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

``select_related()`` now validates that the given fields actually exist.
Previously, nonexistent fields were silently ignored. Now, an error is raised::

    >>> book = Book.objects.select_related('nonexistent_field')
    Traceback (most recent call last):
    ...
    FieldError: Invalid field name(s) given in select_related: 'nonexistent_field'

The validation also makes sure that the given field is relational::

    >>> book = Book.objects.select_related('name')
    Traceback (most recent call last):
    ...
    FieldError: Non-relational field given in select_related: 'name'

Default ``EmailField.max_length`` increased to 254
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

The old default 75 character ``max_length`` was not capable of storing all
possible RFC3696/5321-compliant email addresses. In order to store all
possible valid email addresses, the ``max_length`` has been increased to 254
characters. You will need to generate and apply database migrations for your
affected models (or add ``max_length=75`` if you wish to keep the length on
your current fields). A migration for
:attr:`django.contrib.auth.models.User.email` is included.

Support for PostgreSQL versions older than 9.0
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

The end of upstream support periods was reached in July 2014 for PostgreSQL 8.4.
As a consequence, Django 1.8 sets 9.0 as the minimum PostgreSQL version it
officially supports.

This also includes dropping support for PostGIS 1.3 and 1.4 as these versions
are not supported on versions of PostgreSQL later than 8.4.

Django also now requires the use of Psycopg2 version 2.4.5 or higher (or 2.5+
if you want to use :mod:`django.contrib.postgres`).

Support for MySQL versions older than 5.5
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

The end of upstream support periods was reached in January 2012 for MySQL 5.0
and December 2013 for MySQL 5.1. As a consequence, Django 1.8 sets 5.5 as the
minimum MySQL version it officially supports.

Support for Oracle versions older than 11.1
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

The end of upstream support periods was reached in July 2010 for Oracle 9.2,
January 2012 for Oracle 10.1, and July 2013 for Oracle 10.2. As a consequence,
Django 1.8 sets 11.1 as the minimum Oracle version it officially supports.

Specific privileges used instead of roles for tests on Oracle
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Earlier versions of Django granted the CONNECT and RESOURCE roles to the test
user on Oracle. These roles have been deprecated, so Django 1.8 uses the
specific underlying privileges instead. This changes the privileges required
of the main user for running tests (unless the project is configured to avoid
creating a test user). The exact privileges required now are detailed in
:ref:`Oracle notes <oracle-notes>`.

``AbstractUser.last_login`` allows null values
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

The :attr:`AbstractUser.last_login <django.contrib.auth.models.User.last_login>`
field now allows null values. Previously, it defaulted to the time when the user
was created which was misleading if the user never logged in. Please run the
database migration. If your custom user inherits from ``AbstractUser`` and you
wish to set ``last_login`` to ``NULL`` for users who haven't logged in, you can
run this query::

    from django.db import models
    from django.contrib.auth import get_user_model
    from django.contrib.auth.models import AbstractBaseUser

    UserModel = get_user_model()
    if issubclass(UserModel, AbstractBaseUser):
        UserModel._default_manager.filter(
            last_login=models.F('date_joined')
        ).update(last_login=None)

:mod:`django.contrib.gis`
~~~~~~~~~~~~~~~~~~~~~~~~~

* Support for GEOS 3.1 and GDAL 1.6 has been dropped.

* Support for SpatiaLite < 2.4 has been dropped.

* GIS-specific lookups have been refactored to use the
  :class:`django.db.models.Lookup` API.

* The default ``str`` representation of
  :class:`~django.contrib.gis.geos.GEOSGeometry` objects has been changed from
  WKT to EWKT format (including the SRID). As this representation is used in
  the serialization framework, that means that ``dumpdata`` output will now
  contain the SRID value of geometry objects.

Priority of context processors for ``TemplateResponse`` brought in line with ``render``
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

The :class:`~django.template.response.TemplateResponse` constructor is designed to be a
drop-in replacement for the :func:`~django.shortcuts.render` function. However,
it had a slight incompatibility, in that for ``TemplateResponse``, context data
from the passed in context dictionary could be shadowed by context data returned
from context processors, whereas for ``render`` it was the other way
around. This was a bug, and the behavior of ``render`` is more appropriate,
since it allows the globally defined context processors to be overridden locally
in the view. If you were relying on the fact context data in a
``TemplateResponse`` could be overridden using a context processor, you will
need to change your code.

Overriding ``setUpClass`` / ``tearDownClass`` in test cases
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

The decorators :func:`~django.test.override_settings` and
:func:`~django.test.modify_settings` now act at the class level when used as
class decorators. As a consequence, when overriding ``setUpClass()`` or
``tearDownClass()``, the ``super`` implementation should always be called.

Removal of ``django.contrib.formtools``
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

The formtools contrib app has been moved into a separate package.
``django.contrib.formtools`` itself has been removed. The docs provide
:ref:`migration instructions <formtools-how-to-migrate>`.

The new package is available `on Github`_ and on PyPI.

.. _on GitHub: https://github.com/django/django-formtools/

Database connection reloading between tests
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Django previously closed database connections between each test within a
``TestCase``. This is no longer the case as Django now wraps the whole
``TestCase`` within a transaction. If some of your tests relied on the old
behavior, you should have them inherit from ``TransactionTestCase`` instead.

Cleanup of the ``django.template`` namespace
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

If you've been relying on private APIs exposed in the ``django.template``
module, you may have to import them from ``django.template.base`` instead.

Also private APIs ``django.template.base.compile_string()``,
``django.template.loader.find_template()``, and
``django.template.loader.get_template_from_string()`` were removed.

``model`` attribute on private model relations
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

In earlier versions of Django, on a model with a reverse foreign key
relationship (for example), ``model._meta.get_all_related_objects()`` returned
the relationship as a ``django.db.models.related.RelatedObject`` with the
``model`` attribute set to the source of the relationship. Now, this method
returns the relationship as ``django.db.models.fields.related.ManyToOneRel``
(private API ``RelatedObject`` has been removed), and the ``model`` attribute
is set to the target of the relationship instead of the source. The source
model is accessible on the ``related_model`` attribute instead.

Consider this example from the tutorial in Django 1.8::

    >>> p = Poll.objects.get(pk=1)
    >>> p._meta.get_all_related_objects()
    [<ManyToOneRel: polls.choice>]
    >>> p._meta.get_all_related_objects()[0].model
    <class 'polls.models.Poll'>
    >>> p._meta.get_all_related_objects()[0].related_model
    <class 'polls.models.Choice'>

and compare it to the behavior on older versions::

    >>> p._meta.get_all_related_objects()
    [<RelatedObject: polls:choice related to poll>]
    >>> p._meta.get_all_related_objects()[0].model
    <class 'polls.models.Choice'>

To access the source model, you can use a pattern like this to write code that
will work with both Django 1.8 and older versions::

    for relation in opts.get_all_related_objects():
        to_model = getattr(relation, 'related_model', relation.model)

Also note that ``get_all_related_objects()`` is deprecated in 1.8. See the
:ref:`upgrade guide <migrating-old-meta-api>` for the new API.

Database backend API
~~~~~~~~~~~~~~~~~~~~

The following changes to the database backend API are documented to assist
those writing third-party backends in updating their code:

* ``BaseDatabaseXXX`` classes have been moved to ``django.db.backends.base``.
  Please import them from the new locations::

    from django.db.backends.base.base import BaseDatabaseWrapper
    from django.db.backends.base.client import BaseDatabaseClient
    from django.db.backends.base.creation import BaseDatabaseCreation
    from django.db.backends.base.features import BaseDatabaseFeatures
    from django.db.backends.base.introspection import BaseDatabaseIntrospection
    from django.db.backends.base.introspection import FieldInfo, TableInfo
    from django.db.backends.base.operations import BaseDatabaseOperations
    from django.db.backends.base.schema import BaseDatabaseSchemaEditor
    from django.db.backends.base.validation import BaseDatabaseValidation

* The ``data_types``, ``data_types_suffix``, and
  ``data_type_check_constraints`` attributes have moved from the
  ``DatabaseCreation`` class to ``DatabaseWrapper``.

* The ``SQLCompiler.as_sql()`` method now takes a ``subquery`` parameter
  (:ticket:`24164`).

:mod:`django.contrib.admin`
~~~~~~~~~~~~~~~~~~~~~~~~~~~

* ``AdminSite`` no longer takes an ``app_name`` argument and its ``app_name``
  attribute has been removed. The application name is always ``admin`` (as
  opposed to the instance name which you can still customize using
  ``AdminSite(name="...")``.

* The ``ModelAdmin.get_object()`` method (private API) now takes a third
  argument named ``from_field`` in order to specify which field should match
  the provided ``object_id``.

* The :meth:`ModelAdmin.response_delete()
  <django.contrib.admin.ModelAdmin.response_delete>` method
  now takes a second argument named ``obj_id`` which is the serialized
  identifier used to retrieve the object before deletion.

Miscellaneous
~~~~~~~~~~~~~

* ``connections.queries`` is now a read-only attribute.

* Database connections are considered equal only if they're the same object.
  They aren't hashable any more.

* :class:`~django.middleware.gzip.GZipMiddleware` used to disable compression
  for some content types when the request is from Internet Explorer, in order
  to work around a bug in IE6 and earlier. This behavior could affect
  performance on IE7 and later. It was removed.

* ``URLField.to_python`` no longer adds a trailing slash to pathless URLs.

* The :tfilter:`length` template filter now returns ``0`` for an undefined
  variable, rather than an empty string.

* ``ForeignKey.default_error_message['invalid']`` has been changed from
  ``'%(model)s instance with pk %(pk)r does not exist.'`` to
  ``'%(model)s instance with %(field)s %(value)r does not exist.'`` If you are
  using this message in your own code, please update the list of interpolated
  parameters. Internally, Django will continue to provide the
  ``pk`` parameter in ``params`` for backwards compatibility.

* ``UserCreationForm.errors_messages['duplicate_username']`` is no longer used.
  If you wish to customize that error message, :ref:`override it on the form
  <modelforms-overriding-default-fields>` using the ``'unique'`` key in
  ``Meta.errors_messages['username']`` or, if you have a custom form field for
  ``'username'``, using the the ``'unique'`` key in its
  :attr:`~django.forms.Field.error_messages` argument.

* The block ``usertools`` in the ``base.html`` template of
  :mod:`django.contrib.admin` now requires the ``has_permission`` context
  variable to be set. If you have any custom admin views that use this
  template, update them to pass :meth:`AdminSite.has_permission()
  <django.contrib.admin.AdminSite.has_permission>` as this new variable's
  value or simply include :meth:`AdminSite.each_context(request)
  <django.contrib.admin.AdminSite.each_context>` in the context.

* Internal changes were made to the :class:`~django.forms.ClearableFileInput`
  widget to allow more customization. The undocumented ``url_markup_template``
  attribute was removed in favor of ``template_with_initial``.

* For consistency with other major vendors, the ``en_GB`` locale now has Monday
  as the first day of the week.

* Seconds have been removed from any locales that had them in ``TIME_FORMAT``,
  ``DATETIME_FORMAT``, or ``SHORT_DATETIME_FORMAT``.

* The default max size of the Oracle test tablespace has increased from 300M
  (or 200M, before 1.7.2) to 500M.

* :func:`~django.core.urlresolvers.reverse` and
  :func:`~django.core.urlresolvers.reverse_lazy` now return Unicode strings
  instead of byte strings.

* The ``CacheClass`` shim has been removed from all cache backends.
  These aliases were provided for backwards compatibility with Django 1.3.
  If you are still using them, please update your project to use the real
  class name found in the :setting:`BACKEND <CACHES-BACKEND>` key of the
  :setting:`CACHES` setting.

* By default, :ref:`call_command <call-command>` now always skips the check
  framework (unless you pass it ``skip_checks=False``).

* When iterating over lines, :class:`~django.core.files.File` now uses
  `universal newlines`_. The following are recognized as ending a line: the
  Unix end-of-line convention ``'\n'``, the Windows convention ``'\r\n'``, and
  the old Macintosh convention ``'\r'``.

  .. _universal newlines: https://www.python.org/dev/peps/pep-0278

* The Memcached cache backends ``MemcachedCache`` and ``PyLibMCCache`` will
  delete a key if ``set()`` fails. This is necessary to ensure the ``cache_db``
  session store always fetches the most current session data.

* Private APIs ``override_template_loaders`` and ``override_with_test_loader``
  in ``django.test.utils`` were removed. Override ``TEMPLATES`` with
  ``override_settings`` instead.

* Warnings from the MySQL database backend are no longer converted to
  exceptions when :setting:`DEBUG` is ``True``.

* :class:`~django.http.HttpRequest` now has a simplified ``repr`` (e.g.
  ``<WSGIRequest: GET '/somepath/'>``). This won't change the behavior of
  the :class:`~django.views.debug.SafeExceptionReporterFilter` class.

* Class-based views that use :class:`~django.views.generic.edit.ModelFormMixin`
  will raise an :exc:`~django.core.exceptions.ImproperlyConfigured` exception
  when both the ``fields`` and ``form_class`` attributes are specified.
  Previously, ``fields`` was silently ignored.

* When following redirects, the test client now raises
  :exc:`~django.test.client.RedirectCycleError` if it detects a loop or hits a
  maximum redirect limit (rather than passing silently).

* Translatable strings set as the ``default`` parameter of the field are cast
  to concrete strings later, so the return type of ``Field.get_default()`` is
  different in some cases. There is no change to default values which are the
  result of a callable.

* ``GenericIPAddressField.empty_strings_allowed`` is now ``False``. Database
  backends that interpret empty strings as null (only Oracle among the backends
  that Django includes) will no longer convert null values back to an empty
  string. This is consistent with other backends.

* When the :attr:`~django.core.management.BaseCommand.leave_locale_alone`
  attribute is ``False``, translations are now deactivated instead of forcing
  the "en-us" locale. In the case your models contained non-English strings and
  you counted on English translations to be activated in management commands,
  this will not happen any longer. It might be that new database migrations are
  generated (once) after migrating to 1.8.

* :func:`django.utils.translation.get_language()` now returns ``None`` instead
  of :setting:`LANGUAGE_CODE` when translations are temporarily deactivated.

* The migration operations :class:`~django.db.migrations.operations.RunPython`
  and :class:`~django.db.migrations.operations.RunSQL` now call the
  :meth:`allow_migrate` method of database routers. In these cases the
  ``model`` argument of ``allow_migrate()`` is set to ``None``, so the router
  must properly handle this value. This is most useful when used together with
  the newly introduced ``hints`` parameter for these operations, but it can
  also be used to disable migrations from running on a particular database.

* The ``name`` field of :class:`django.contrib.contenttypes.models.ContentType`
  has been removed by a migration and replaced by a property. That means it's
  not possible to query or filter a ``ContentType`` by this field any longer.

* :djadmin:`migrate` now accepts the :djadminopt:`--fake-initial` option to
  allow faking initial migrations. In 1.7 initial migrations were always
  automatically faked if all tables created in an initial migration already
  existed.

.. _deprecated-features-1.8:

Features deprecated in 1.8
==========================

Selected methods in ``django.db.models.options.Options``
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

As part of the formalization of the ``Model._meta`` API (from the
:class:`django.db.models.options.Options` class), a number of methods have been
deprecated and will be removed in Django 2.0:

* ``get_all_field_names()``
* ``get_all_related_objects()``
* ``get_all_related_objects_with_model()``
* ``get_all_related_many_to_many_objects()``
* ``get_all_related_m2m_objects_with_model()``
* ``get_concrete_fields_with_model()``
* ``get_field_by_name()``
* ``get_fields_with_model()``
* ``get_m2m_with_model()``

A :ref:`migration guide <migrating-old-meta-api>` has been provided to assist
in converting your code from the old API to the new, official API.

Loading ``cycle`` and ``firstof`` template tags from ``future`` library
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Django 1.6 introduced ``{% load cycle from future %}`` and
``{% load firstof from future %}`` syntax for forward compatibility of the
:ttag:`cycle` and :ttag:`firstof` template tags. This syntax is now deprecated
and will be removed in Django 2.0. You can simply remove the
``{% load ... from future %}`` tags.

``django.conf.urls.patterns()``
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

In the olden days of Django, it was encouraged to reference views as strings
in ``urlpatterns``::

    urlpatterns = patterns('',
        url('^$', 'myapp.views.myview'),
    )

and Django would magically import ``myapp.views.myview`` internally and turn
the string into a real function reference. In order to reduce repetition when
referencing many views from the same module, the ``patterns()`` function takes
a required initial ``prefix`` argument which is prepended to all
views-as-strings in that set of ``urlpatterns``::

    urlpatterns = patterns('myapp.views',
        url('^$', 'myview'),
        url('^other/$', 'otherview'),
    )

In the modern era, we have updated the tutorial to instead recommend importing
your views module and referencing your view functions (or classes) directly.
This has a number of advantages, all deriving from the fact that we are using
normal Python in place of "Django String Magic": the errors when you mistype a
view name are less obscure, IDEs can help with autocompletion of view names,
etc.

So these days, the above use of the ``prefix`` arg is much more likely to be
written (and is better written) as::

    from myapp import views

    urlpatterns = patterns('',
        url('^$', views.myview),
        url('^other/$', views.otherview),
    )

Thus ``patterns()`` serves little purpose and is a burden when teaching new users
(answering the newbie's question "why do I need this empty string as the first
argument to ``patterns()``?"). For these reasons, we are deprecating it.
Updating your code is as simple as ensuring that ``urlpatterns`` is a list of
:func:`django.conf.urls.url` instances. For example::

    from django.conf.urls import url
    from myapp import views

    urlpatterns = [
        url('^$', views.myview),
        url('^other/$', views.otherview),
    ]

Passing a string as ``view`` to :func:`~django.conf.urls.url`
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Related to the previous item, referencing views as strings in the ``url()``
function is deprecated. Pass the callable view as described in the previous
section instead.

Template-related settings
~~~~~~~~~~~~~~~~~~~~~~~~~

As a consequence of the multiple template engines refactor, several settings
are deprecated in favor of :setting:`TEMPLATES`:

* ``ALLOWED_INCLUDE_ROOTS``
* ``TEMPLATE_CONTEXT_PROCESSORS``
* ``TEMPLATE_DEBUG``
* ``TEMPLATE_DIRS``
* ``TEMPLATE_LOADERS``
* ``TEMPLATE_STRING_IF_INVALID``

``django.core.context_processors``
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Built-in template context processors have been moved to
``django.template.context_processors``.

``django.test.SimpleTestCase.urls``
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

The attribute :attr:`SimpleTestCase.urls <django.test.SimpleTestCase.urls>`
for specifying URLconf configuration in tests has been deprecated and will be
removed in Django 2.0. Use :func:`@override_settings(ROOT_URLCONF=...)
<django.test.override_settings>` instead.

``prefix`` argument to :func:`~django.conf.urls.i18n.i18n_patterns`
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Related to the previous item, the ``prefix`` argument to
:func:`django.conf.urls.i18n.i18n_patterns` has been deprecated. Simply pass a
list of :func:`django.conf.urls.url` instances instead.

Using an incorrect count of unpacked values in the :ttag:`for` template tag
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Using an incorrect count of unpacked values in :ttag:`for` tag will raise an
exception rather than fail silently in Django 2.0.

Passing a dotted path to :func:`~django.core.urlresolvers.reverse()` and :ttag:`url`
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Reversing URLs by Python path is an expensive operation as it causes the
path being reversed to be imported. This behavior has also resulted in a
`security issue`_. Use :ref:`named URL patterns <naming-url-patterns>`
for reversing instead.

If you are using :mod:`django.contrib.sitemaps`, add the ``name`` argument to
the ``url`` that references :func:`django.contrib.sitemaps.views.sitemap`::

    from django.contrib.sitemaps.views import sitemap

    url(r'^sitemap\.xml$', sitemap, {'sitemaps': sitemaps},
        name='django.contrib.sitemaps.views.sitemap')

to ensure compatibility when reversing by Python path is removed in Django 2.0.

Similarly for GIS sitemaps, add ``name='django.contrib.gis.sitemaps.views.kml'``
or ``name='django.contrib.gis.sitemaps.views.kmz'``.

.. _security issue: https://www.djangoproject.com/weblog/2014/apr/21/security/#s-issue-unexpected-code-execution-using-reverse

Aggregate methods and modules
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

The ``django.db.models.sql.aggregates`` and
``django.contrib.gis.db.models.sql.aggregates`` modules (both private API), have
been deprecated as ``django.db.models.aggregates`` and
``django.contrib.gis.db.models.aggregates`` are now also responsible
for SQL generation. The old modules will be removed in Django 2.0.

If you were using the old modules, see :doc:`Query Expressions
</ref/models/expressions>` for instructions on rewriting custom aggregates
using the new stable API.

The following methods and properties of ``django.db.models.sql.query.Query``
have also been deprecated and the backwards compatibility shims will be removed
in Django 2.0:

* ``Query.aggregates``, replaced by ``annotations``.
* ``Query.aggregate_select``, replaced by ``annotation_select``.
* ``Query.add_aggregate()``, replaced by ``add_annotation()``.
* ``Query.set_aggregate_mask()``, replaced by ``set_annotation_mask()``.
* ``Query.append_aggregate_mask()``, replaced by ``append_annotation_mask()``.

Extending management command arguments through ``Command.option_list``
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Management commands now use :py:mod:`argparse` instead of :py:mod:`optparse` to
parse command-line arguments passed to commands. This also means that the way
to add custom arguments to commands has changed: instead of extending the
``option_list`` class list, you should now override the
:meth:`~django.core.management.BaseCommand.add_arguments` method and add
arguments through ``argparse.add_argument()``. See
:ref:`this example <custom-commands-options>` for more details.

``django.core.management.NoArgsCommand``
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

The class :class:`~django.core.management.NoArgsCommand` is now deprecated and
will be removed in Django 2.0. Use :class:`~django.core.management.BaseCommand`
instead, which takes no arguments by default.

Listing all migrations in a project
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

The ``--list`` option of the :djadmin:`migrate` management command is
deprecated and will be removed in Django 2.0. Use :djadmin:`showmigrations`
instead.

``cache_choices`` option of ``ModelChoiceField`` and ``ModelMultipleChoiceField``
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

:class:`~django.forms.ModelChoiceField` and
:class:`~django.forms.ModelMultipleChoiceField` took an undocumented, untested
option ``cache_choices``. This cached querysets between multiple renderings of
the same ``Form`` object. This option is subject to an accelerated deprecation
and will be removed in Django 1.9.

``django.template.resolve_variable()``
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

The function has been informally marked as "Deprecated" for some time. Replace
``resolve_variable(path, context)`` with
``django.template.Variable(path).resolve(context)``.

``django.contrib.webdesign``
~~~~~~~~~~~~~~~~~~~~~~~~~~~~

It provided the :ttag:`lorem` template tag which is now included in the
built-in tags. Simply remove ``'django.contrib.webdesign'`` from
:setting:`INSTALLED_APPS` and ``{% load webdesign %}`` from your templates.

``error_message`` argument to ``django.forms.RegexField``
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

It provided backwards compatibility for pre-1.0 code, but its functionality is
redundant. Use ``Field.error_messages['invalid']`` instead.

Old :tfilter:`unordered_list` syntax
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

An older (pre-1.0), more restrictive and verbose input format for the
:tfilter:`unordered_list` template filter has been deprecated::

    ``['States', [['Kansas', [['Lawrence', []], ['Topeka', []]]], ['Illinois', []]]]``

Using the new syntax, this becomes::

    ``['States', ['Kansas', ['Lawrence', 'Topeka'], 'Illinois']]``

``django.forms.Field._has_changed()``
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Rename this method to :meth:`~django.forms.Field.has_changed` by removing the
leading underscore. The old name will still work until Django 2.0.

``django.utils.html.remove_tags()`` and ``removetags`` template filter
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

``django.utils.html.remove_tags()`` as well as the template filter
``removetags`` have been deprecated as they cannot guarantee safe output. Their
existence is likely to lead to their use in security-sensitive contexts where
they are not actually safe.

The unused and undocumented ``django.utils.html.strip_entities()`` function has
also been deprecated.

``is_admin_site`` argument to ``django.contrib.auth.views.password_reset()``
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

It's a legacy option that should no longer be necessary.

``SubfieldBase``
~~~~~~~~~~~~~~~~

``django.db.models.fields.subclassing.SubfieldBase`` has been deprecated and
will be removed in Django 2.0. Historically, it was used to handle fields where
type conversion was needed when loading from the database, but it was not used
in ``.values()`` calls or in aggregates. It has been replaced with
:meth:`~django.db.models.Field.from_db_value`. Note that the new approach does
not call the :meth:`~django.db.models.Field.to_python` method on assignment
as was the case with ``SubfieldBase``.

``django.utils.checksums``
~~~~~~~~~~~~~~~~~~~~~~~~~~

The ``django.utils.checksums`` module has been deprecated and will be removed
in Django 2.0. The functionality it provided (validating checksum using the
Luhn algorithm) was undocumented and not used in Django. The module has been
moved to the `django-localflavor`_ package (version 1.1+).

.. _django-localflavor: https://pypi.python.org/pypi/django-localflavor

``InlineAdminForm.original_content_type_id``
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

The ``original_content_type_id`` attribute on ``InlineAdminForm`` has been
deprecated and will be removed in Django 2.0. Historically, it was used
to construct the "view on site" URL. This URL is now accessible using the
``absolute_url`` attribute of the form.

``django.views.generic.edit.FormMixin.get_form()``’s ``form_class`` argument
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

``FormMixin`` subclasses that override the ``get_form()`` method should make
sure to provide a default value for the ``form_class`` argument since it's
now optional.

Rendering templates loaded by :func:`~django.template.loader.get_template()` with a :class:`~django.template.Context`
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

The return type of :func:`~django.template.loader.get_template()` has changed
in Django 1.8: instead of a :class:`django.template.Template`, it returns a
``Template`` instance whose exact type depends on which backend loaded it.

Both classes provide a ``render()`` method, however, the former takes a
:class:`django.template.Context` as an argument while the latter expects a
:class:`dict`. This change is enforced through a deprecation path for Django
templates.

Since it's easier to understand with examples, the :ref:`upgrade guide
<get_template-upgrade-django-18>` shows how to adapt affected code.

All this also applies to :func:`~django.template.loader.select_template()`.

:class:`~django.template.Template` and :class:`~django.template.Context` classes in template responses
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Some methods of :class:`~django.template.response.SimpleTemplateResponse` and
:class:`~django.template.response.TemplateResponse` accepted
:class:`django.template.Context` and :class:`django.template.Template` objects
as arguments. They should now receive :class:`dict` and backend-dependent
template objects respectively.

This also applies to the return types if you have subclassed either template
response class.

Check the :doc:`template response API documentation </ref/template-response>`
for details.

``current_app`` argument of template-related APIs
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

The following functions and classes will no longer accept a ``current_app``
parameter to set an URL namespace in Django 2.0:

* ``django.shortcuts.render()``
* ``django.template.Context()``
* ``django.template.RequestContext()``
* ``django.template.response.TemplateResponse()``

Set ``request.current_app`` instead, where ``request`` is the first argument
to these functions or classes. If you're using a plain ``Context``, use a
``RequestContext`` instead.

``dictionary`` and ``context_instance`` arguments of rendering functions
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

The following functions will no longer accept the ``dictionary`` and
``context_instance`` parameters in Django 2.0:

* ``django.shortcuts.render()``
* ``django.shortcuts.render_to_response()``
* ``django.template.loader.render_to_string()``

Use the ``context`` parameter instead. When ``dictionary`` is passed as a
positional argument, which is the most common idiom, no changes are needed.

If you're passing a :class:`~django.template.Context` in ``context_instance``,
pass a :class:`dict` in the ``context`` parameter instead. If you're passing a
:class:`~django.template.RequestContext`, pass the request separately in the
``request`` parameter.

``dirs`` argument of template-finding functions
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

The following functions will no longer accept a ``dirs`` parameter to override
``TEMPLATE_DIRS`` in Django 2.0:

* :func:`django.template.loader.get_template()`
* :func:`django.template.loader.select_template()`
* :func:`django.shortcuts.render()`
* :func:`django.shortcuts.render_to_response()`

The parameter didn't work consistently across different template loaders and
didn't work for included templates.

``django.template.loader.BaseLoader``
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

``django.template.loader.BaseLoader`` was renamed to
``django.template.loaders.base.Loader``. If you've written a custom template
loader that inherits ``BaseLoader``, you must inherit ``Loader`` instead.

``django.test.utils.TestTemplateLoader``
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Private API ``django.test.utils.TestTemplateLoader`` is deprecated in favor of
``django.template.loaders.locmem.Loader`` and will be removed in Django 1.9.

.. _storage-max-length-update:

Support for the ``max_length`` argument on custom ``Storage`` classes
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

``Storage`` subclasses should add ``max_length=None`` as a parameter to
:meth:`~django.core.files.storage.Storage.get_available_name` and/or
:meth:`~django.core.files.storage.Storage.save` if they override either method.
Support for storages that do not accept this argument will be removed in
Django 2.0.

``qn`` replaced by ``compiler``
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

In previous Django versions, various internal ORM methods (mostly ``as_sql``
methods) accepted a ``qn`` (for "quote name") argument, which was a reference
to a function that quoted identifiers for sending to the database. In Django
1.8, that argument has been renamed to ``compiler`` and is now a full
``SQLCompiler`` instance. For backwards-compatibility, calling a
``SQLCompiler`` instance performs the same name-quoting that the ``qn``
function used to. However, this backwards-compatibility shim is immediately
deprecated: you should rename your ``qn`` arguments to ``compiler``, and call
``compiler.quote_name_unless_alias(...)`` where you previously called
``qn(...)``.

Default value of ``RedirectView.permanent``
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

The default value of the
:attr:`RedirectView.permanent <django.views.generic.base.RedirectView.permanent>`
attribute will change from ``True`` to ``False`` in Django 1.9.

Using ``AuthenticationMiddleware`` without ``SessionAuthenticationMiddleware``
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

:class:`django.contrib.auth.middleware.SessionAuthenticationMiddleware` was
added in Django 1.7. In Django 1.7.2, its functionality was moved to
``auth.get_user()`` and, for backwards compatibility, enabled only if
``'django.contrib.auth.middleware.SessionAuthenticationMiddleware'`` appears in
:setting:`MIDDLEWARE_CLASSES`.

In Django 2.0, session verification will be enabled regardless of whether or not
``SessionAuthenticationMiddleware`` is enabled (at which point
``SessionAuthenticationMiddleware`` will have no significance). You can add it
to your ``MIDDLEWARE_CLASSES`` sometime before then to opt-in. Please read the
:ref:`upgrade considerations <session-invalidation-on-password-change>` first.

``django.contrib.sitemaps.FlatPageSitemap``
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

``django.contrib.sitemaps.FlatPageSitemap`` has moved to
``django.contrib.flatpages.sitemaps.FlatPageSitemap``. The old import location
is deprecated and will be removed in Django 1.9.

Model ``Field.related``
~~~~~~~~~~~~~~~~~~~~~~~

Private attribute ``django.db.models.Field.related`` is deprecated in favor
of ``Field.rel``.  The latter is an instance of
``django.db.models.fields.related.ForeignObjectRel`` which replaces
``django.db.models.related.RelatedObject``. The ``django.db.models.related``
module has been removed and the ``Field.related`` attribute will be removed in
Django 2.0.

``ssi`` template tag
~~~~~~~~~~~~~~~~~~~~

The :ttag:`ssi` template tag allows files to be included in a template by
absolute path. This is of limited use in most deployment situations, and
the :ttag:`include` tag often makes more sense. This tag is now deprecated and
will be removed in Django 2.0.

``=`` as comparison operator in ``if`` template tag
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Using a single equals sign with the ``{% if %}`` template tag for equality
testing was undocumented and untested. It's now deprecated in favor of ``==``.

``%(<foo>)s`` syntax in ``ModelFormMixin.success_url``
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

The legacy ``%(<foo>)s`` syntax in :attr:`ModelFormMixin.success_url
<django.views.generic.edit.ModelFormMixin.success_url>` is deprecated and
will be removed in Django 2.0.

``GeoQuerySet`` aggregate methods
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

The ``collect()``, ``extent()``, ``extent3d()``, ``makeline()``, and ``union()``
aggregate methods are deprecated and should be replaced by their function-based
aggregate equivalents (``Collect``, ``Extent``, ``Extent3D``, ``MakeLine``, and
``Union``).

.. removed-features-1.8:

Features removed in 1.8
=======================

These features have reached the end of their deprecation cycle and so have been
removed in Django 1.8 (please see the :ref:`deprecation timeline
<deprecation-removed-in-1.8>` for more details):

* ``django.contrib.comments`` is removed.

* The following transaction management APIs are removed:

  - ``TransactionMiddleware``
  - the decorators and context managers ``autocommit``, ``commit_on_success``,
    and ``commit_manually``, defined in ``django.db.transaction``
  - the functions ``commit_unless_managed`` and ``rollback_unless_managed``,
    also defined in ``django.db.transaction``
  - the ``TRANSACTIONS_MANAGED`` setting

* The :ttag:`cycle` and :ttag:`firstof` template tags auto-escape their
  arguments.

* The ``SEND_BROKEN_LINK_EMAILS`` setting is removed.

* ``django.middleware.doc.XViewMiddleware`` is removed.

* The ``Model._meta.module_name`` alias is removed.

* The backward compatible shims introduced to rename ``get_query_set``
  and similar queryset methods are removed. This affects the following classes:
  ``BaseModelAdmin``, ``ChangeList``, ``BaseCommentNode``,
  ``GenericForeignKey``, ``Manager``, ``SingleRelatedObjectDescriptor`` and
  ``ReverseSingleRelatedObjectDescriptor``.

* The backward compatible shims introduced to rename the attributes
  ``ChangeList.root_query_set`` and ``ChangeList.query_set`` are removed.

* ``django.views.defaults.shortcut`` and ``django.conf.urls.shortcut`` are
  removed.

* Support for the Python Imaging Library (PIL) module is removed.

* The following private APIs are removed:

  - ``django.db.backend``
  - ``django.db.close_connection()``
  - ``django.db.backends.creation.BaseDatabaseCreation.set_autocommit()``
  - ``django.db.transaction.is_managed()``
  - ``django.db.transaction.managed()``

* ``django.forms.widgets.RadioInput`` is removed.

* The module ``django.test.simple`` and the class
  ``django.test.simple.DjangoTestSuiteRunner`` are removed.

* The module ``django.test._doctest`` is removed.

* The ``CACHE_MIDDLEWARE_ANONYMOUS_ONLY`` setting is removed.

* Usage of the hard-coded *Hold down "Control", or "Command" on a Mac, to select
  more than one.* string to override or append to user-provided ``help_text`` in
  forms for ``ManyToMany`` model fields is not be performed by Django anymore
  either at the model or forms layer.

* The ``Model._meta.get_(add|change|delete)_permission`` methods are removed.

* The session key ``django_language`` is no longer read for backwards
  compatibility.

* Geographic Sitemaps are removed
  (``django.contrib.gis.sitemaps.views.index`` and
  ``django.contrib.gis.sitemaps.views.sitemap``).

* ``django.utils.html.fix_ampersands``, the ``fix_ampersands`` template filter,
  and ``django.utils.html.clean_html`` are removed.