forked from firebase/firebase-admin-python
-
Notifications
You must be signed in to change notification settings - Fork 0
Expand file tree
/
Copy pathdb.py
More file actions
801 lines (643 loc) · 30.1 KB
/
db.py
File metadata and controls
801 lines (643 loc) · 30.1 KB
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
# Copyright 2017 Google Inc.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
"""Firebase Realtime Database module.
This module contains functions and classes that facilitate interacting with the Firebase Realtime
Database. It supports basic data manipulation operations, as well as complex queries such as
limit queries and range queries. However, it does not support realtime update notifications. This
module uses the Firebase REST API underneath.
"""
import collections
import json
import sys
import requests
import six
from six.moves import urllib
import firebase_admin
from firebase_admin import _http_client
from firebase_admin import _utils
_DB_ATTRIBUTE = '_database'
_INVALID_PATH_CHARACTERS = '[].#$'
_RESERVED_FILTERS = ('$key', '$value', '$priority')
_USER_AGENT = 'Firebase/HTTP/{0}/{1}.{2}/AdminPython'.format(
firebase_admin.__version__, sys.version_info.major, sys.version_info.minor)
_TRANSACTION_MAX_RETRIES = 25
def reference(path='/', app=None):
"""Returns a database Reference representing the node at the specified path.
If no path is specified, this function returns a Reference that represents the database root.
Args:
path: Path to a node in the Firebase realtime database (optional).
app: An App instance (optional).
Returns:
Reference: A newly initialized Reference.
Raises:
ValueError: If the specified path or app is invalid.
"""
client = _utils.get_app_service(app, _DB_ATTRIBUTE, _Client.from_app)
return Reference(client=client, path=path)
def _parse_path(path):
"""Parses a path string into a set of segments."""
if not isinstance(path, six.string_types):
raise ValueError('Invalid path: "{0}". Path must be a string.'.format(path))
if any(ch in path for ch in _INVALID_PATH_CHARACTERS):
raise ValueError(
'Invalid path: "{0}". Path contains illegal characters.'.format(path))
return [seg for seg in path.split('/') if seg]
class Reference(object):
"""Reference represents a node in the Firebase realtime database."""
def __init__(self, **kwargs):
"""Creates a new Reference using the provided parameters.
This method is for internal use only. Use db.reference() to obtain an instance of
Reference.
"""
self._client = kwargs.get('client')
if 'segments' in kwargs:
self._segments = kwargs.get('segments')
else:
self._segments = _parse_path(kwargs.get('path'))
self._pathurl = '/' + '/'.join(self._segments)
@property
def key(self):
if self._segments:
return self._segments[-1]
return None
@property
def path(self):
return self._pathurl
@property
def parent(self):
if self._segments:
return Reference(client=self._client, segments=self._segments[:-1])
return None
def child(self, path):
"""Returns a Reference to the specified child node.
The path may point to an immediate child of the current Reference, or a deeply nested
child. Child paths must not begin with '/'.
Args:
path: Path to the child node.
Returns:
Reference: A database Reference representing the specified child node.
Raises:
ValueError: If the child path is not a string, not well-formed or begins with '/'.
"""
if not path or not isinstance(path, six.string_types):
raise ValueError(
'Invalid path argument: "{0}". Path must be a non-empty string.'.format(path))
if path.startswith('/'):
raise ValueError(
'Invalid path argument: "{0}". Child path must not start with "/"'.format(path))
full_path = self._pathurl + '/' + path
return Reference(client=self._client, path=full_path)
def get(self, etag=False, shallow=False):
"""Returns the value, and optionally the ETag, at the current location of the database.
Args:
etag: A boolean indicating whether the Etag value should be returned or not (optional).
shallow: A boolean indicating whether to execute a shallow read (optional). Shallow
reads do not retrieve the child nodes of the current database location. Cannot be
set to True if ``etag`` is also set to True.
Returns:
object: If etag is False returns the decoded JSON value of the current database location.
If etag is True, returns a 2-tuple consisting of the decoded JSON value and the Etag
associated with the current database location.
Raises:
ValueError: If both ``etag`` and ``shallow`` are set to True.
ApiCallError: If an error occurs while communicating with the remote database server.
"""
if etag:
if shallow:
raise ValueError('etag and shallow cannot both be set to True.')
headers, data = self._client.headers_and_body(
'get', self._add_suffix(), headers={'X-Firebase-ETag' : 'true'})
return data, headers.get('ETag')
else:
params = 'shallow=true' if shallow else None
return self._client.body('get', self._add_suffix(), params=params)
def get_if_changed(self, etag):
"""Gets data in this location only if the specified ETag does not match.
Args:
etag: The ETag value to be checked against the ETag of the current location.
Returns:
tuple: A 3-tuple consisting of a boolean, a decoded JSON value and an ETag. If the ETag
specified by the caller did not match, the boolen value will be True and the JSON
and ETag values would reflect the corresponding values in the database. If the ETag
matched, the boolean value will be False and the other elements of the tuple will be
None.
Raises:
ValueError: If the ETag is not a string.
ApiCallError: If an error occurs while communicating with the remote database server.
"""
if not isinstance(etag, six.string_types):
raise ValueError('ETag must be a string.')
resp = self._client.request('get', self._add_suffix(), headers={'if-none-match': etag})
if resp.status_code == 304:
return False, None, None
else:
return True, resp.json(), resp.headers.get('ETag')
def set(self, value):
"""Sets the data at this location to the given value.
The value must be JSON-serializable and not None.
Args:
value: JSON-serializable value to be set at this location.
Raises:
ValueError: If the provided value is None.
TypeError: If the value is not JSON-serializable.
ApiCallError: If an error occurs while communicating with the remote database server.
"""
if value is None:
raise ValueError('Value must not be None.')
self._client.request('put', self._add_suffix(), json=value, params='print=silent')
def set_if_unchanged(self, expected_etag, value):
"""Conditonally sets the data at this location to the given value.
Sets the data at this location to the given value only if ``expected_etag`` is same as the
ETag value in the database.
Args:
expected_etag: Value of ETag we want to check.
value: JSON-serializable value to be set at this location.
Returns:
tuple: A 3-tuple consisting of a boolean, a decoded JSON value and an ETag. The boolean
indicates whether the set operation was successful or not. The decoded JSON and the
ETag corresponds to the latest value in this database location.
Raises:
ValueError: If the value is None, or if expected_etag is not a string.
ApiCallError: If an error occurs while communicating with the remote database server.
"""
# pylint: disable=missing-raises-doc
if not isinstance(expected_etag, six.string_types):
raise ValueError('Expected ETag must be a string.')
if value is None:
raise ValueError('Value must not be none.')
try:
headers = self._client.headers(
'put', self._add_suffix(), json=value, headers={'if-match': expected_etag})
return True, value, headers.get('ETag')
except ApiCallError as error:
detail = error.detail
if detail.response is not None and 'ETag' in detail.response.headers:
etag = detail.response.headers['ETag']
snapshot = detail.response.json()
return False, snapshot, etag
else:
raise error
def push(self, value=''):
"""Creates a new child node.
The optional value argument can be used to provide an initial value for the child node. If
no value is provided, child node will have empty string as the default value.
Args:
value: JSON-serializable initial value for the child node (optional).
Returns:
Reference: A Reference representing the newly created child node.
Raises:
ValueError: If the value is None.
TypeError: If the value is not JSON-serializable.
ApiCallError: If an error occurs while communicating with the remote database server.
"""
if value is None:
raise ValueError('Value must not be None.')
output = self._client.body('post', self._add_suffix(), json=value)
push_id = output.get('name')
return self.child(push_id)
def update(self, value):
"""Updates the specified child keys of this Reference to the provided values.
Args:
value: A dictionary containing the child keys to update, and their new values.
Raises:
ValueError: If value is empty or not a dictionary.
ApiCallError: If an error occurs while communicating with the remote database server.
"""
if not value or not isinstance(value, dict):
raise ValueError('Value argument must be a non-empty dictionary.')
if None in value.keys() or None in value.values():
raise ValueError('Dictionary must not contain None keys or values.')
self._client.request('patch', self._add_suffix(), json=value, params='print=silent')
def delete(self):
"""Deletes this node from the database.
Raises:
ApiCallError: If an error occurs while communicating with the remote database server.
"""
self._client.request('delete', self._add_suffix())
def transaction(self, transaction_update):
"""Atomically modifies the data at this location.
Unlike a normal ``set()``, which just overwrites the data regardless of its previous state,
``transaction()`` is used to modify the existing value to a new value, ensuring there are
no conflicts with other clients simultaneously writing to the same location.
This is accomplished by passing an update function which is used to transform the current
value of this reference into a new value. If another client writes to this location before
the new value is successfully saved, the update function is called again with the new
current value, and the write will be retried. In case of repeated failures, this method
will retry the transaction up to 25 times before giving up and raising a TransactionError.
The update function may also force an early abort by raising an exception instead of
returning a value.
Args:
transaction_update: A function which will be passed the current data stored at this
location. The function should return the new value it would like written. If
an exception is raised, the transaction will be aborted, and the data at this
location will not be modified. The exceptions raised by this function are
propagated to the caller of the transaction method.
Returns:
object: New value of the current database Reference (only if the transaction commits).
Raises:
TransactionError: If the transaction aborts after exhausting all retry attempts.
ValueError: If transaction_update is not a function.
"""
if not callable(transaction_update):
raise ValueError('transaction_update must be a function.')
tries = 0
data, etag = self.get(etag=True)
while tries < _TRANSACTION_MAX_RETRIES:
new_data = transaction_update(data)
success, data, etag = self.set_if_unchanged(etag, new_data)
if success:
return new_data
tries += 1
raise TransactionError('Transaction aborted after failed retries.')
def order_by_child(self, path):
"""Returns a Query that orders data by child values.
Returned Query can be used to set additional parameters, and execute complex database
queries (e.g. limit queries, range queries).
Args:
path: Path to a valid child of the current Reference.
Returns:
Query: A database Query instance.
Raises:
ValueError: If the child path is not a string, not well-formed or None.
"""
if path in _RESERVED_FILTERS:
raise ValueError('Illegal child path: {0}'.format(path))
return Query(order_by=path, client=self._client, pathurl=self._add_suffix())
def order_by_key(self):
"""Creates a Query that orderes data by key.
Returned Query can be used to set additional parameters, and execute complex database
queries (e.g. limit queries, range queries).
Returns:
Query: A database Query instance.
"""
return Query(order_by='$key', client=self._client, pathurl=self._add_suffix())
def order_by_value(self):
"""Creates a Query that orderes data by value.
Returned Query can be used to set additional parameters, and execute complex database
queries (e.g. limit queries, range queries).
Returns:
Query: A database Query instance.
"""
return Query(order_by='$value', client=self._client, pathurl=self._add_suffix())
def _add_suffix(self, suffix='.json'):
return self._pathurl + suffix
class Query(object):
"""Represents a complex query that can be executed on a Reference.
Complex queries can consist of up to 2 components: a required ordering constraint, and an
optional filtering constraint. At the server, data is first sorted according to the given
ordering constraint (e.g. order by child). Then the filtering constraint (e.g. limit, range)
is applied on the sorted data to produce the final result. Despite the ordering constraint,
the final result is returned by the server as an unordered collection. Therefore the Query
interface performs another round of sorting at the client-side before returning the results
to the caller. This client-side sorted results are returned to the user as a Python
OrderedDict.
"""
def __init__(self, **kwargs):
order_by = kwargs.pop('order_by')
if not order_by or not isinstance(order_by, six.string_types):
raise ValueError('order_by field must be a non-empty string')
if order_by not in _RESERVED_FILTERS:
if order_by.startswith('/'):
raise ValueError('Invalid path argument: "{0}". Child path must not start '
'with "/"'.format(order_by))
segments = _parse_path(order_by)
order_by = '/'.join(segments)
self._client = kwargs.pop('client')
self._pathurl = kwargs.pop('pathurl')
self._order_by = order_by
self._params = {'orderBy' : json.dumps(order_by)}
if kwargs:
raise ValueError('Unexpected keyword arguments: {0}'.format(kwargs))
def limit_to_first(self, limit):
"""Creates a query with limit, and anchors it to the start of the window.
Args:
limit: The maximum number of child nodes to return.
Returns:
Query: The updated Query instance.
Raises:
ValueError: If the value is not an integer, or set_limit_last() was called previously.
"""
if not isinstance(limit, int) or limit < 0:
raise ValueError('Limit must be a non-negative integer.')
if 'limitToLast' in self._params:
raise ValueError('Cannot set both first and last limits.')
self._params['limitToFirst'] = limit
return self
def limit_to_last(self, limit):
"""Creates a query with limit, and anchors it to the end of the window.
Args:
limit: The maximum number of child nodes to return.
Returns:
Query: The updated Query instance.
Raises:
ValueError: If the value is not an integer, or set_limit_first() was called previously.
"""
if not isinstance(limit, int) or limit < 0:
raise ValueError('Limit must be a non-negative integer.')
if 'limitToFirst' in self._params:
raise ValueError('Cannot set both first and last limits.')
self._params['limitToLast'] = limit
return self
def start_at(self, start):
"""Sets the lower bound for a range query.
The Query will only return child nodes with a value greater than or equal to the specified
value.
Args:
start: JSON-serializable value to start at, inclusive.
Returns:
Query: The updated Query instance.
Raises:
ValueError: If the value is ``None``.
"""
if start is None:
raise ValueError('Start value must not be None.')
self._params['startAt'] = json.dumps(start)
return self
def end_at(self, end):
"""Sets the upper bound for a range query.
The Query will only return child nodes with a value less than or equal to the specified
value.
Args:
end: JSON-serializable value to end at, inclusive.
Returns:
Query: The updated Query instance.
Raises:
ValueError: If the value is ``None``.
"""
if end is None:
raise ValueError('End value must not be None.')
self._params['endAt'] = json.dumps(end)
return self
def equal_to(self, value):
"""Sets an equals constraint on the Query.
The Query will only return child nodes whose value is equal to the specified value.
Args:
value: JSON-serializable value to query for.
Returns:
Query: The updated Query instance.
Raises:
ValueError: If the value is ``None``.
"""
if value is None:
raise ValueError('Equal to value must not be None.')
self._params['equalTo'] = json.dumps(value)
return self
@property
def _querystr(self):
params = []
for key in sorted(self._params):
params.append('{0}={1}'.format(key, self._params[key]))
return '&'.join(params)
def get(self):
"""Executes this Query and returns the results.
The results will be returned as a sorted list or an OrderedDict.
Returns:
object: Decoded JSON result of the Query.
Raises:
ApiCallError: If an error occurs while communicating with the remote database server.
"""
result = self._client.body('get', self._pathurl, params=self._querystr)
if isinstance(result, (dict, list)) and self._order_by != '$priority':
return _Sorter(result, self._order_by).get()
return result
class ApiCallError(Exception):
"""Represents an Exception encountered while invoking the Firebase database server API."""
def __init__(self, message, error):
Exception.__init__(self, message)
self.detail = error
class TransactionError(Exception):
"""Represents an Exception encountered while performing a transaction."""
def __init__(self, message):
Exception.__init__(self, message)
class _Sorter(object):
"""Helper class for sorting query results."""
def __init__(self, results, order_by):
if isinstance(results, dict):
self.dict_input = True
entries = [_SortEntry(k, v, order_by) for k, v in results.items()]
elif isinstance(results, list):
self.dict_input = False
entries = [_SortEntry(k, v, order_by) for k, v in enumerate(results)]
else:
raise ValueError('Sorting not supported for "{0}" object.'.format(type(results)))
self.sort_entries = sorted(entries)
def get(self):
if self.dict_input:
return collections.OrderedDict([(e.key, e.value) for e in self.sort_entries])
else:
return [e.value for e in self.sort_entries]
class _SortEntry(object):
"""A wrapper that is capable of sorting items in a dictionary."""
_type_none = 0
_type_bool_false = 1
_type_bool_true = 2
_type_numeric = 3
_type_string = 4
_type_object = 5
def __init__(self, key, value, order_by):
self._key = key
self._value = value
if order_by == '$key' or order_by == '$priority':
self._index = key
elif order_by == '$value':
self._index = value
else:
self._index = _SortEntry._extract_child(value, order_by)
self._index_type = _SortEntry._get_index_type(self._index)
@property
def key(self):
return self._key
@property
def index(self):
return self._index
@property
def index_type(self):
return self._index_type
@property
def value(self):
return self._value
@classmethod
def _get_index_type(cls, index):
"""Assigns an integer code to the type of the index.
The index type determines how differently typed values are sorted. This ordering is based
on https://firebase.google.com/docs/database/rest/retrieve-data#section-rest-ordered-data
"""
if index is None:
return cls._type_none
elif isinstance(index, bool) and not index:
return cls._type_bool_false
elif isinstance(index, bool) and index:
return cls._type_bool_true
elif isinstance(index, (int, float)):
return cls._type_numeric
elif isinstance(index, six.string_types):
return cls._type_string
else:
return cls._type_object
@classmethod
def _extract_child(cls, value, path):
segments = path.split('/')
current = value
for segment in segments:
if isinstance(current, dict):
current = current.get(segment)
else:
return None
return current
def _compare(self, other):
"""Compares two _SortEntry instances.
If the indices have the same numeric or string type, compare them directly. Ties are
broken by comparing the keys. If the indices have the same type, but are neither numeric
nor string, compare the keys. In all other cases compare based on the ordering provided
by index types.
"""
self_key, other_key = self.index_type, other.index_type
if self_key == other_key:
if self_key in (self._type_numeric, self._type_string) and self.index != other.index:
self_key, other_key = self.index, other.index
else:
self_key, other_key = self.key, other.key
if self_key < other_key:
return -1
elif self_key > other_key:
return 1
else:
return 0
def __lt__(self, other):
return self._compare(other) < 0
def __le__(self, other):
return self._compare(other) <= 0
def __gt__(self, other):
return self._compare(other) > 0
def __ge__(self, other):
return self._compare(other) >= 0
def __eq__(self, other):
return self._compare(other) is 0
class _Client(_http_client.JsonHttpClient):
"""HTTP client used to make REST calls.
_Client maintains an HTTP session, and handles authenticating HTTP requests along with
marshalling and unmarshalling of JSON data.
"""
_DEFAULT_AUTH_OVERRIDE = '_admin_'
def __init__(self, credential, base_url, auth_override=_DEFAULT_AUTH_OVERRIDE, timeout=None):
"""Creates a new _Client from the given parameters.
This exists primarily to enable testing. For regular use, obtain _Client instances by
calling the from_app() class method.
Args:
credential: A Google credential that can be used to authenticate requests.
base_url: A URL prefix to be added to all outgoing requests. This is typically the
Firebase Realtime Database URL.
auth_override: A dictionary representing auth variable overrides or None (optional).
Default value provides admin privileges. A None value here provides un-authenticated
guest privileges.
timeout: HTTP request timeout in seconds (optional). If not set connections will never
timeout, which is the default behavior of the underlying requests library.
"""
_http_client.JsonHttpClient.__init__(
self, credential=credential, base_url=base_url, headers={'User-Agent': _USER_AGENT})
if auth_override != self._DEFAULT_AUTH_OVERRIDE and auth_override != {}:
encoded = json.dumps(auth_override, separators=(',', ':'))
self._auth_override = 'auth_variable_override={0}'.format(encoded)
else:
self._auth_override = None
self._timeout = timeout
@classmethod
def from_app(cls, app):
"""Creates a new _Client for a given App"""
credential = app.credential.get_credential()
db_url = cls._get_db_url(app)
auth_override = cls._get_auth_override(app)
timeout = app.options.get('httpTimeout')
return _Client(credential, db_url, auth_override, timeout)
@classmethod
def _get_db_url(cls, app):
"""Retrieves and parses the database URL option."""
url = app.options.get('databaseURL')
if not url or not isinstance(url, six.string_types):
raise ValueError(
'Invalid databaseURL option: "{0}". databaseURL must be a non-empty URL '
'string.'.format(url))
parsed = urllib.parse.urlparse(url)
if parsed.scheme != 'https':
raise ValueError(
'Invalid databaseURL option: "{0}". databaseURL must be an HTTPS URL.'.format(url))
elif not parsed.netloc.endswith('.firebaseio.com'):
raise ValueError(
'Invalid databaseURL option: "{0}". databaseURL must be a valid URL to a '
'Firebase Realtime Database instance.'.format(url))
return 'https://{0}'.format(parsed.netloc)
@classmethod
def _get_auth_override(cls, app):
auth_override = app.options.get('databaseAuthVariableOverride', cls._DEFAULT_AUTH_OVERRIDE)
if auth_override == cls._DEFAULT_AUTH_OVERRIDE or auth_override is None:
return auth_override
if not isinstance(auth_override, dict):
raise ValueError('Invalid databaseAuthVariableOverride option: "{0}". Override '
'value must be a dict or None.'.format(auth_override))
else:
return auth_override
@property
def auth_override(self):
return self._auth_override
@property
def timeout(self):
return self._timeout
def request(self, method, url, **kwargs):
"""Makes an HTTP call using the Python requests library.
Extends the request() method of the parent JsonHttpClient class. Handles auth overrides,
and low-level exceptions.
Args:
method: HTTP method name as a string (e.g. get, post).
url: URL path of the remote endpoint. This will be appended to the server's base URL.
kwargs: An additional set of keyword arguments to be passed into requests API
(e.g. json, params).
Returns:
Response: An HTTP response object.
Raises:
ApiCallError: If an error occurs while making the HTTP call.
"""
if self._auth_override:
params = kwargs.get('params')
if params:
params += '&{0}'.format(self._auth_override)
else:
params = self._auth_override
kwargs['params'] = params
if self._timeout:
kwargs['timeout'] = self._timeout
try:
return super(_Client, self).request(method, url, **kwargs)
except requests.exceptions.RequestException as error:
raise ApiCallError(self._extract_error_message(error), error)
def _extract_error_message(self, error):
"""Extracts an error message from an exception.
If the server has not sent any response, simply converts the exception into a string.
If the server has sent a JSON response with an 'error' field, which is the typical
behavior of the Realtime Database REST API, parses the response to retrieve the error
message. If the server has sent a non-JSON response, returns the full response
as the error message.
Args:
error: An exception raised by the requests library.
Returns:
str: A string error message extracted from the exception.
"""
if error.response is None:
return str(error)
try:
data = error.response.json()
if isinstance(data, dict):
return '{0}\nReason: {1}'.format(error, data.get('error', 'unknown'))
except ValueError:
pass
return '{0}\nReason: {1}'.format(error, error.response.content.decode())