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
|
import json
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.utils.translation import ugettext_lazy as _
__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(JsonAdapter, self).__init__(adapted, dumps=dumps)
def dumps(self, obj):
options = {'cls': self.encoder} if self.encoder else {}
return json.dumps(obj, **options)
class JSONField(Field):
empty_strings_allowed = False
description = _('A JSON object')
default_error_messages = {
'invalid': _("Value must be valid JSON."),
}
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(JSONField, self).__init__(verbose_name, name, **kwargs)
def db_type(self, connection):
return 'jsonb'
def deconstruct(self):
name, path, args, kwargs = super(JSONField, self).deconstruct()
if self.encoder is not None:
kwargs['encoder'] = self.encoder
return name, path, args, kwargs
def get_transform(self, name):
transform = super(JSONField, self).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(JSONField, self).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):
defaults = {'form_class': forms.JSONField}
defaults.update(kwargs)
return super(JSONField, self).formfield(**defaults)
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)
class KeyTransform(Transform):
operator = '->'
nested_operator = '#>'
def __init__(self, key_name, *args, **kwargs):
super(KeyTransform, self).__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), [key_transforms] + params
try:
lookup = int(self.key_name)
except ValueError:
lookup = self.key_name
return '(%s %s %%s)' % (lhs, self.operator), [lookup] + params
class KeyTextTransform(KeyTransform):
operator = '->>'
nested_operator = '#>>'
_output_field = TextField()
class KeyTransformTextLookupMixin(object):
"""
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
)
super(KeyTransformTextLookupMixin, self).__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(object):
def __init__(self, key_name):
self.key_name = key_name
def __call__(self, *args, **kwargs):
return KeyTransform(self.key_name, *args, **kwargs)
|
