Refs #28370 -- Removed support for the context arg of Field.from_db_value() and Expression.convert_value().

Per deprecation timeline.

django/contrib/postgres/fields/array.py

@@ -6,7 +6,6 @@ from django.contrib.postgres.validators import ArrayMaxLengthValidator
 from django.core import checks, exceptions
 from django.db.models import Field, IntegerField, Transform
 from django.db.models.lookups import Exact, In
-from django.utils.inspect import func_supports_parameter
 from django.utils.translation import gettext_lazy as _
 
 from ..utils import prefix_validation_error
@@ -112,9 +111,7 @@ class ArrayField(CheckFieldDefaultMixin, Field):
         if value is None:
             return value
         return [
-            self.base_field.from_db_value(item, expression, connection, {})
-            if func_supports_parameter(self.base_field.from_db_value, 'context')  # RemovedInDjango30Warning
-            else self.base_field.from_db_value(item, expression, connection)
+            self.base_field.from_db_value(item, expression, connection)
             for item in value
         ]
 

django/core/cache/backends/db.py

@@ -7,7 +7,6 @@ from django.conf import settings
 from django.core.cache.backends.base import DEFAULT_TIMEOUT, BaseCache
 from django.db import DatabaseError, connections, models, router, transaction
 from django.utils import timezone
-from django.utils.inspect import func_supports_parameter
 
 
 class Options:
@@ -85,10 +84,7 @@ class DatabaseCache(BaseDatabaseCache):
         converters = (connection.ops.get_db_converters(expression) + expression.get_db_converters(connection))
         for key, value, expires in rows:
             for converter in converters:
-                if func_supports_parameter(converter, 'context'):  # RemovedInDjango30Warning
-                    expires = converter(expires, expression, connection, {})
-                else:
-                    expires = converter(expires, expression, connection)
+                expires = converter(expires, expression, connection)
             if expires < timezone.now():
                 expired_keys.append(key)
             else:
@@ -160,10 +156,7 @@ class DatabaseCache(BaseDatabaseCache):
                         expression = models.Expression(output_field=models.DateTimeField())
                         for converter in (connection.ops.get_db_converters(expression) +
                                           expression.get_db_converters(connection)):
-                            if func_supports_parameter(converter, 'context'):  # RemovedInDjango30Warning
-                                current_expires = converter(current_expires, expression, connection, {})
-                            else:
-                                current_expires = converter(current_expires, expression, connection)
+                            current_expires = converter(current_expires, expression, connection)
 
                     exp = connection.ops.adapt_datetimefield_value(exp)
                     if result and mode == 'touch':

django/db/models/sql/compiler.py

@@ -1,5 +1,4 @@
 import collections
-import functools
 import re
 import warnings
 from itertools import chain
@@ -14,10 +13,7 @@ from django.db.models.sql.constants import (
 from django.db.models.sql.query import Query, get_order_dir
 from django.db.transaction import TransactionManagementError
 from django.db.utils import DatabaseError, NotSupportedError
-from django.utils.deprecation import (
-    RemovedInDjango30Warning, RemovedInDjango31Warning,
-)
-from django.utils.inspect import func_supports_parameter
+from django.utils.deprecation import RemovedInDjango31Warning
 
 FORCE = object()
 
@@ -1015,20 +1011,7 @@ class SQLCompiler:
                 backend_converters = self.connection.ops.get_db_converters(expression)
                 field_converters = expression.get_db_converters(self.connection)
                 if backend_converters or field_converters:
-                    convs = []
-                    for conv in (backend_converters + field_converters):
-                        if func_supports_parameter(conv, 'context'):
-                            warnings.warn(
-                                'Remove the context parameter from %s.%s(). Support for it '
-                                'will be removed in Django 3.0.' % (
-                                    conv.__self__.__class__.__name__,
-                                    conv.__name__,
-                                ),
-                                RemovedInDjango30Warning,
-                            )
-                            conv = functools.partial(conv, context={})
-                        convs.append(conv)
-                    converters[i] = (convs, expression)
+                    converters[i] = (backend_converters + field_converters, expression)
         return converters
 
     def apply_converters(self, rows, converters):

docs/releases/3.0.txt

@@ -244,6 +244,9 @@ to remove usage of these features.
 
 * ``HttpRequest.xreadlines()`` is removed.
 
+* Support for the ``context`` argument of ``Field.from_db_value()`` and
+  ``Expression.convert_value()`` is removed.
+
 See :ref:`deprecated-features-2.1` for details on these changes, including how
 to remove usage of these features.
 

tests/from_db_value/models.py

@@ -28,12 +28,3 @@ class CashModel(models.Model):
 
     def __str__(self):
         return str(self.cash)
-
-
-class CashFieldDeprecated(CashField):
-    def from_db_value(self, value, expression, connection, context):
-        return super().from_db_value(value, expression, connection)
-
-
-class CashModelDeprecated(models.Model):
-    cash = CashFieldDeprecated()

tests/from_db_value/test_deprecated.py

@@ -1,17 +0,0 @@
-from django.test import TestCase
-from django.utils.deprecation import RemovedInDjango30Warning
-
-from .models import Cash, CashModelDeprecated
-
-
-class FromDBValueDeprecationTests(TestCase):
-
-    def test_deprecation(self):
-        msg = (
-            'Remove the context parameter from CashFieldDeprecated.from_db_value(). '
-            'Support for it will be removed in Django 3.0.'
-        )
-        CashModelDeprecated.objects.create(cash='12.50')
-        with self.assertWarnsMessage(RemovedInDjango30Warning, msg):
-            instance = CashModelDeprecated.objects.get()
-        self.assertIsInstance(instance.cash, Cash)