Fixed #12990, Refs #27694 -- Added JSONField model field.

Thanks to Adam Johnson, Carlton Gibson, Mariusz Felisiak, and Raphael
Michel for mentoring this Google Summer of Code 2019 project and
everyone else who helped with the patch.

Special thanks to Mads Jensen, Nick Pope, and Simon Charette for
extensive reviews.

Co-authored-by: Mariusz Felisiak <felisiak.mariusz@gmail.com>

1 files changed, 30 insertions, 172 deletions

diff --git a/django/contrib/postgres/fields/jsonb.py b/django/contrib/postgres/fields/jsonb.py
index c402dd19d8..7f76b29a13 100644
--- a/django/contrib/postgres/fields/jsonb.py
+++ b/django/contrib/postgres/fields/jsonb.py
@@ -1,185 +1,43 @@
-import json
+import warnings
 
-from psycopg2.extras import Json
-
-from django.contrib.postgres import forms, lookups
-from django.core import exceptions
-from django.db.models import (
-    Field, TextField, Transform, lookups as builtin_lookups,
+from django.db.models import JSONField as BuiltinJSONField
+from django.db.models.fields.json import (
+    KeyTextTransform as BuiltinKeyTextTransform,
+    KeyTransform as BuiltinKeyTransform,
 )
-from django.db.models.fields.mixins import CheckFieldDefaultMixin
-from django.utils.translation import gettext_lazy as _
+from django.utils.deprecation import RemovedInDjango40Warning
 
 __all__ = ['JSONField']
 
 
-class JsonAdapter(Json):
-    """
-    Customized psycopg2.extras.Json to allow for a custom encoder.
-    """
-    def __init__(self, adapted, dumps=None, encoder=None):
-        self.encoder = encoder
-        super().__init__(adapted, dumps=dumps)
-
-    def dumps(self, obj):
-        options = {'cls': self.encoder} if self.encoder else {}
-        return json.dumps(obj, **options)
-
-
-class JSONField(CheckFieldDefaultMixin, Field):
-    empty_strings_allowed = False
-    description = _('A JSON object')
-    default_error_messages = {
-        'invalid': _("Value must be valid JSON."),
+class JSONField(BuiltinJSONField):
+    system_check_deprecated_details = {
+        'msg': (
+            'django.contrib.postgres.fields.JSONField is deprecated. Support '
+            'for it (except in historical migrations) will be removed in '
+            'Django 4.0.'
+        ),
+        'hint': 'Use django.db.models.JSONField instead.',
+        'id': 'fields.W904',
     }
-    _default_hint = ('dict', '{}')
-
-    def __init__(self, verbose_name=None, name=None, encoder=None, **kwargs):
-        if encoder and not callable(encoder):
-            raise ValueError("The encoder parameter must be a callable object.")
-        self.encoder = encoder
-        super().__init__(verbose_name, name, **kwargs)
-
-    def db_type(self, connection):
-        return 'jsonb'
-
-    def deconstruct(self):
-        name, path, args, kwargs = super().deconstruct()
-        if self.encoder is not None:
-            kwargs['encoder'] = self.encoder
-        return name, path, args, kwargs
-
-    def get_transform(self, name):
-        transform = super().get_transform(name)
-        if transform:
-            return transform
-        return KeyTransformFactory(name)
-
-    def get_prep_value(self, value):
-        if value is not None:
-            return JsonAdapter(value, encoder=self.encoder)
-        return value
-
-    def validate(self, value, model_instance):
-        super().validate(value, model_instance)
-        options = {'cls': self.encoder} if self.encoder else {}
-        try:
-            json.dumps(value, **options)
-        except TypeError:
-            raise exceptions.ValidationError(
-                self.error_messages['invalid'],
-                code='invalid',
-                params={'value': value},
-            )
-
-    def value_to_string(self, obj):
-        return self.value_from_object(obj)
 
-    def formfield(self, **kwargs):
-        return super().formfield(**{
-            'form_class': forms.JSONField,
-            **kwargs,
-        })
 
-
-JSONField.register_lookup(lookups.DataContains)
-JSONField.register_lookup(lookups.ContainedBy)
-JSONField.register_lookup(lookups.HasKey)
-JSONField.register_lookup(lookups.HasKeys)
-JSONField.register_lookup(lookups.HasAnyKeys)
-JSONField.register_lookup(lookups.JSONExact)
-
-
-class KeyTransform(Transform):
-    operator = '->'
-    nested_operator = '#>'
-
-    def __init__(self, key_name, *args, **kwargs):
+class KeyTransform(BuiltinKeyTransform):
+    def __init__(self, *args, **kwargs):
+        warnings.warn(
+            'django.contrib.postgres.fields.jsonb.KeyTransform is deprecated '
+            'in favor of django.db.models.fields.json.KeyTransform.',
+            RemovedInDjango40Warning, stacklevel=2,
+        )
         super().__init__(*args, **kwargs)
-        self.key_name = key_name
 
-    def as_sql(self, compiler, connection):
-        key_transforms = [self.key_name]
-        previous = self.lhs
-        while isinstance(previous, KeyTransform):
-            key_transforms.insert(0, previous.key_name)
-            previous = previous.lhs
-        lhs, params = compiler.compile(previous)
-        if len(key_transforms) > 1:
-            return '(%s %s %%s)' % (lhs, self.nested_operator), params + [key_transforms]
-        try:
-            lookup = int(self.key_name)
-        except ValueError:
-            lookup = self.key_name
-        return '(%s %s %%s)' % (lhs, self.operator), tuple(params) + (lookup,)
 
-
-class KeyTextTransform(KeyTransform):
-    operator = '->>'
-    nested_operator = '#>>'
-    output_field = TextField()
-
-
-class KeyTransformTextLookupMixin:
-    """
-    Mixin for combining with a lookup expecting a text lhs from a JSONField
-    key lookup. Make use of the ->> operator instead of casting key values to
-    text and performing the lookup on the resulting representation.
-    """
-    def __init__(self, key_transform, *args, **kwargs):
-        assert isinstance(key_transform, KeyTransform)
-        key_text_transform = KeyTextTransform(
-            key_transform.key_name, *key_transform.source_expressions, **key_transform.extra
+class KeyTextTransform(BuiltinKeyTextTransform):
+    def __init__(self, *args, **kwargs):
+        warnings.warn(
+            'django.contrib.postgres.fields.jsonb.KeyTextTransform is '
+            'deprecated in favor of '
+            'django.db.models.fields.json.KeyTextTransform.',
+            RemovedInDjango40Warning, stacklevel=2,
         )
-        super().__init__(key_text_transform, *args, **kwargs)
-
-
-class KeyTransformIExact(KeyTransformTextLookupMixin, builtin_lookups.IExact):
-    pass
-
-
-class KeyTransformIContains(KeyTransformTextLookupMixin, builtin_lookups.IContains):
-    pass
-
-
-class KeyTransformStartsWith(KeyTransformTextLookupMixin, builtin_lookups.StartsWith):
-    pass
-
-
-class KeyTransformIStartsWith(KeyTransformTextLookupMixin, builtin_lookups.IStartsWith):
-    pass
-
-
-class KeyTransformEndsWith(KeyTransformTextLookupMixin, builtin_lookups.EndsWith):
-    pass
-
-
-class KeyTransformIEndsWith(KeyTransformTextLookupMixin, builtin_lookups.IEndsWith):
-    pass
-
-
-class KeyTransformRegex(KeyTransformTextLookupMixin, builtin_lookups.Regex):
-    pass
-
-
-class KeyTransformIRegex(KeyTransformTextLookupMixin, builtin_lookups.IRegex):
-    pass
-
-
-KeyTransform.register_lookup(KeyTransformIExact)
-KeyTransform.register_lookup(KeyTransformIContains)
-KeyTransform.register_lookup(KeyTransformStartsWith)
-KeyTransform.register_lookup(KeyTransformIStartsWith)
-KeyTransform.register_lookup(KeyTransformEndsWith)
-KeyTransform.register_lookup(KeyTransformIEndsWith)
-KeyTransform.register_lookup(KeyTransformRegex)
-KeyTransform.register_lookup(KeyTransformIRegex)
-
-
-class KeyTransformFactory:
-
-    def __init__(self, key_name):
-        self.key_name = key_name
-
-    def __call__(self, *args, **kwargs):
-        return KeyTransform(self.key_name, *args, **kwargs)
+        super().__init__(*args, **kwargs)