-
Notifications
You must be signed in to change notification settings - Fork 34
/
connection_field.py
404 lines (318 loc) · 11.9 KB
/
connection_field.py
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
# Standard Library
from contextlib import suppress
from functools import partial
from typing import cast
# GraphQL
import graphene_sqlalchemy
from graphene.utils.str_converters import to_snake_case
from promise import Promise, dataloader
# Database
from sqlalchemy import inspection, tuple_
from sqlalchemy.orm import Load, aliased, contains_eager
MYPY = False
if MYPY:
from typing import (
Any,
Callable,
Dict,
List,
Optional,
Tuple,
Type,
Union,
) # noqa: F401; pragma: no cover
from graphql import ResolveInfo # noqa: F401; pragma: no cover
from graphene.relay import Connection # noqa: F401; pragma: no cover
from sqlalchemy.orm import Query # noqa: F401; pragma: no cover
from .filters import FilterSet # noqa: F401; pragma: no cover
graphene_sqlalchemy_version_lt_2_1_2 = tuple(
map(int, graphene_sqlalchemy.__version__.split('.'))
) < (2, 1, 2)
if graphene_sqlalchemy_version_lt_2_1_2:
default_connection_field_factory = None # pragma: no cover
else:
from graphene_sqlalchemy.fields import default_connection_field_factory
DEFAULT_FILTER_ARG: str = 'filters'
class FilterableConnectionField(graphene_sqlalchemy.SQLAlchemyConnectionField):
filter_arg: str = DEFAULT_FILTER_ARG
factory: 'Union[FilterableFieldFactory, Callable, None]' = None
filters: dict = {}
def __init_subclass__(cls):
if graphene_sqlalchemy_version_lt_2_1_2:
return # pragma: no cover
if cls.filters and cls.factory is None:
cls.factory = FilterableFieldFactory(cls.filters)
if cls.filter_arg != DEFAULT_FILTER_ARG:
# Update filter arg for nested fields.
cls.factory.model_loader_class = type(
'CustomModelLoader',
(ModelLoader,),
{'filter_arg': cls.filter_arg},
)
elif cls.factory is None:
cls.factory = default_connection_field_factory
def __init__(self, connection, *args, **kwargs):
if self.filter_arg not in kwargs:
model = connection._meta.node._meta.model
with suppress(KeyError):
kwargs[self.filter_arg] = self.filters[model]
super().__init__(connection, *args, **kwargs)
@classmethod
def get_query(cls, model, info: 'ResolveInfo', sort=None, **args):
"""Standard get_query with filtering."""
query = super().get_query(model, info, sort, **args)
request_filters = args.get(cls.filter_arg)
if request_filters:
filter_set = cls.get_filter_set(info)
query = filter_set.filter(info, query, request_filters)
return query
@classmethod
def get_filter_set(cls, info: 'ResolveInfo') -> 'FilterSet':
"""
Get field filter set.
Args:
info: Graphene resolve info object.
Returns:
FilterSet class from field args.
"""
field_name = info.field_asts[0].name.value
schema_field = info.parent_type.fields.get(field_name)
filters_type = schema_field.args[cls.filter_arg].type
filters: 'FilterSet' = filters_type.graphene_type
return filters
class ModelLoader(dataloader.DataLoader):
filter_arg: str = DEFAULT_FILTER_ARG
def __init__(
self,
parent_model: 'Any',
model: 'Any',
info: 'ResolveInfo',
graphql_args: dict,
):
"""
Dataloader for SQLAlchemy model relations.
Args:
parent_model: Parent SQLAlchemy model.
model: SQLAlchemy model.
info: Graphene resolve info object.
graphql_args: Request args: filters, sort, ...
"""
super().__init__()
self.info: 'ResolveInfo' = info
self.graphql_args: dict = graphql_args
self.model: 'Any' = model
self.parent_model: 'Any' = parent_model
self.parent_model_pks: 'Tuple[str, ...]' = self._get_model_pks(
self.parent_model
)
self.parent_model_pk_fields: tuple = tuple(
getattr(self.parent_model, pk) for pk in self.parent_model_pks
)
self.model_relation_field: str = to_snake_case(self.info.field_name)
self.relation: 'Any' = getattr(
self.parent_model, self.model_relation_field
)
def batch_load_fn(self, keys: 'List[tuple]') -> Promise:
"""
Load related objects.
Args:
keys: Primary key values of parent model.
Returns:
Lists of related orm objects.
"""
if len(self.parent_model_pk_fields) == 1:
left_hand_side = self.parent_model_pk_fields[0]
right_hand_side = [k[0] for k in keys]
else:
left_hand_side = tuple_(*self.parent_model_pk_fields)
right_hand_side = keys
query: 'Query' = self._get_query().filter(
left_hand_side.in_(right_hand_side)
)
objects: 'Dict[tuple, Any]' = {
self.parent_model_object_to_key(parent_object): getattr(
parent_object, self.model_relation_field
)
for parent_object in query
}
return Promise.resolve(
[objects.get(object_id, []) for object_id in keys]
)
@staticmethod
def _get_model_pks(model) -> 'Tuple[str, ...]':
"""
Get primary key field name.
Args:
model: SQLAlchemy model.
Returns:
Field name.
"""
model_pk_fields: 'Tuple[str]' = tuple(
(
cast(str, name)
for name, c in inspection.inspect(model).columns.items()
if c.primary_key
)
)
return model_pk_fields
def parent_model_object_to_key(self, parent_object: 'Any') -> 'Any':
"""
Get primary key value from SQLAlchemy orm object.
Args:
parent_object: SQLAlchemy orm object.
Returns:
Primary key value.
"""
key = tuple(getattr(parent_object, pk) for pk in self.parent_model_pks)
return key
@classmethod
def _get_filter_set(cls, info: 'ResolveInfo') -> 'FilterSet':
"""
Get field filter set.
Args:
info: Graphene resolve info object.
Returns:
FilterSet class from field args.
"""
field_name = info.field_asts[0].name.value
schema_field = info.parent_type.fields.get(field_name)
filters_type = schema_field.args[cls.filter_arg].type
filters: 'FilterSet' = filters_type.graphene_type
return filters
def _get_query(self) -> 'Query':
"""
Build, filter and sort the query.
Returns:
SQLAlchemy query.
"""
subquery = graphene_sqlalchemy.get_query(self.model, self.info.context)
request_filters = self.graphql_args.get(self.filter_arg)
if request_filters:
filter_set = self._get_filter_set(self.info)
subquery = filter_set.filter(self.info, subquery, request_filters)
aliased_model = aliased(
self.model, subquery.subquery(with_labels=True)
)
query = (
graphene_sqlalchemy.get_query(self.parent_model, self.info.context)
.join(aliased_model, self.relation)
.options(
contains_eager(self.relation, alias=aliased_model),
Load(self.parent_model).load_only(*self.parent_model_pks),
)
)
query = self._sorted_query(
query, self.graphql_args.get('sort'), aliased_model
)
return query
def _sorted_query(
self, query: 'Query', sort: 'Optional[list]', by_model: 'Any'
) -> 'Query':
"""Sort query."""
order = []
for s in sort:
sort_field_name = s.value
if not isinstance(sort_field_name, str):
sort_field_name = sort_field_name.element.name
sort_field = getattr(by_model, sort_field_name)
if s.endswith('_ASC'):
sort_field = sort_field.asc()
elif s.endswith('_DESC'):
sort_field = sort_field.desc()
order.append(sort_field)
query = query.order_by(*order)
return query
class NestedFilterableConnectionField(FilterableConnectionField):
dataloaders_field: str = '_sqla_filter_dataloaders'
@classmethod
def _get_or_create_data_loader(
cls, root: 'Any', model: 'Any', info: 'ResolveInfo', args: dict
) -> ModelLoader:
"""
Get or create (and save) dataloader from ResolveInfo
Args:
root: Parent model orm object.
model: SQLAlchemy model.
info: Graphene resolve info object.
args: Request args: filters, sort, ...
Returns:
Dataloader for SQLAlchemy model.
"""
context: 'Union[dict, object]' = info.context
if isinstance(context, dict):
try:
data_loaders = context[cls.dataloaders_field]
except KeyError:
data_loaders = {}
context[cls.dataloaders_field] = data_loaders
else:
data_loaders = getattr(context, cls.dataloaders_field, None)
if data_loaders is None:
data_loaders = {}
setattr(info.context, cls.dataloaders_field, data_loaders)
# Unique dataloader key for context.
data_loader_key = tuple((p for p in info.path if isinstance(p, str)))
try:
current_data_loader: ModelLoader = data_loaders[data_loader_key]
except KeyError:
current_data_loader = ModelLoader(type(root), model, info, args)
data_loaders[data_loader_key] = current_data_loader
return current_data_loader
@classmethod
def connection_resolver(
cls,
resolver: 'Any',
connection_type: 'Any',
model: 'Any',
root: 'Any',
info: 'ResolveInfo',
**kwargs: dict,
) -> 'Union[Promise, Connection]':
"""
Resolve nested connection.
Args:
resolver: Default resolver.
connection_type: Connection class.
model: SQLAlchemy model.
root: Parent SQLAlchemy object.
info: Graphene resolve info object.
**kwargs: Request args: filters, sort, ...
Returns:
Connection object.
"""
data_loader: ModelLoader = cls._get_or_create_data_loader(
root, model, info, kwargs
)
root_pk_value: tuple = data_loader.parent_model_object_to_key(root)
resolved: Promise = data_loader.load(root_pk_value)
on_resolve = partial(
cls.resolve_connection, connection_type, model, info, kwargs
)
return Promise.resolve(resolved).then(on_resolve)
class FilterableFieldFactory:
model_loader_class: 'Type[ModelLoader]' = ModelLoader
field_class: 'Type[NestedFilterableConnectionField]' = (
NestedFilterableConnectionField
)
def __init__(self, model_filters: dict):
self.model_filters: dict = model_filters
def __call__(
self, relationship: 'Any', registry: 'Any' = None, **field_kwargs: dict
) -> NestedFilterableConnectionField:
"""
Get field for relation.
Args:
relationship: SQLAlchemy relation.
registry: graphene-sqlalchemy registry.
**field_kwargs: Field args.
Returns:
Filed object.
"""
model = relationship.mapper.entity
model_type = registry.get_type_for_model(model)
filters: 'Optional[FilterSet]' = self.model_filters.get(model)
if filters is not None:
field_kwargs.setdefault(
self.model_loader_class.filter_arg, filters
)
return self.field_class(model_type._meta.connection, **field_kwargs)