-
-
Notifications
You must be signed in to change notification settings - Fork 16.1k
/
app.py
2042 lines (1692 loc) · 78.1 KB
/
app.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
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
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
import os
import sys
import weakref
from datetime import timedelta
from itertools import chain
from threading import Lock
from werkzeug.datastructures import Headers
from werkzeug.datastructures import ImmutableDict
from werkzeug.exceptions import BadRequest
from werkzeug.exceptions import BadRequestKeyError
from werkzeug.exceptions import HTTPException
from werkzeug.exceptions import InternalServerError
from werkzeug.routing import BuildError
from werkzeug.routing import Map
from werkzeug.routing import RequestRedirect
from werkzeug.routing import RoutingException
from werkzeug.routing import Rule
from werkzeug.wrappers import BaseResponse
from . import cli
from . import json
from .config import Config
from .config import ConfigAttribute
from .ctx import _AppCtxGlobals
from .ctx import AppContext
from .ctx import RequestContext
from .globals import _request_ctx_stack
from .globals import g
from .globals import request
from .globals import session
from .helpers import find_package
from .helpers import get_debug_flag
from .helpers import get_env
from .helpers import get_flashed_messages
from .helpers import get_load_dotenv
from .helpers import locked_cached_property
from .helpers import url_for
from .json import jsonify
from .logging import create_logger
from .scaffold import _endpoint_from_view_func
from .scaffold import _sentinel
from .scaffold import Scaffold
from .scaffold import setupmethod
from .sessions import SecureCookieSessionInterface
from .signals import appcontext_tearing_down
from .signals import got_request_exception
from .signals import request_finished
from .signals import request_started
from .signals import request_tearing_down
from .templating import DispatchingJinjaLoader
from .templating import Environment
from .wrappers import Request
from .wrappers import Response
def _make_timedelta(value):
if value is None or isinstance(value, timedelta):
return value
return timedelta(seconds=value)
class Flask(Scaffold):
"""The flask object implements a WSGI application and acts as the central
object. It is passed the name of the module or package of the
application. Once it is created it will act as a central registry for
the view functions, the URL rules, template configuration and much more.
The name of the package is used to resolve resources from inside the
package or the folder the module is contained in depending on if the
package parameter resolves to an actual python package (a folder with
an :file:`__init__.py` file inside) or a standard module (just a ``.py`` file).
For more information about resource loading, see :func:`open_resource`.
Usually you create a :class:`Flask` instance in your main module or
in the :file:`__init__.py` file of your package like this::
from flask import Flask
app = Flask(__name__)
.. admonition:: About the First Parameter
The idea of the first parameter is to give Flask an idea of what
belongs to your application. This name is used to find resources
on the filesystem, can be used by extensions to improve debugging
information and a lot more.
So it's important what you provide there. If you are using a single
module, `__name__` is always the correct value. If you however are
using a package, it's usually recommended to hardcode the name of
your package there.
For example if your application is defined in :file:`yourapplication/app.py`
you should create it with one of the two versions below::
app = Flask('yourapplication')
app = Flask(__name__.split('.')[0])
Why is that? The application will work even with `__name__`, thanks
to how resources are looked up. However it will make debugging more
painful. Certain extensions can make assumptions based on the
import name of your application. For example the Flask-SQLAlchemy
extension will look for the code in your application that triggered
an SQL query in debug mode. If the import name is not properly set
up, that debugging information is lost. (For example it would only
pick up SQL queries in `yourapplication.app` and not
`yourapplication.views.frontend`)
.. versionadded:: 0.7
The `static_url_path`, `static_folder`, and `template_folder`
parameters were added.
.. versionadded:: 0.8
The `instance_path` and `instance_relative_config` parameters were
added.
.. versionadded:: 0.11
The `root_path` parameter was added.
.. versionadded:: 1.0
The ``host_matching`` and ``static_host`` parameters were added.
.. versionadded:: 1.0
The ``subdomain_matching`` parameter was added. Subdomain
matching needs to be enabled manually now. Setting
:data:`SERVER_NAME` does not implicitly enable it.
:param import_name: the name of the application package
:param static_url_path: can be used to specify a different path for the
static files on the web. Defaults to the name
of the `static_folder` folder.
:param static_folder: The folder with static files that is served at
``static_url_path``. Relative to the application ``root_path``
or an absolute path. Defaults to ``'static'``.
:param static_host: the host to use when adding the static route.
Defaults to None. Required when using ``host_matching=True``
with a ``static_folder`` configured.
:param host_matching: set ``url_map.host_matching`` attribute.
Defaults to False.
:param subdomain_matching: consider the subdomain relative to
:data:`SERVER_NAME` when matching routes. Defaults to False.
:param template_folder: the folder that contains the templates that should
be used by the application. Defaults to
``'templates'`` folder in the root path of the
application.
:param instance_path: An alternative instance path for the application.
By default the folder ``'instance'`` next to the
package or module is assumed to be the instance
path.
:param instance_relative_config: if set to ``True`` relative filenames
for loading the config are assumed to
be relative to the instance path instead
of the application root.
:param root_path: The path to the root of the application files.
This should only be set manually when it can't be detected
automatically, such as for namespace packages.
"""
#: The class that is used for request objects. See :class:`~flask.Request`
#: for more information.
request_class = Request
#: The class that is used for response objects. See
#: :class:`~flask.Response` for more information.
response_class = Response
#: The class that is used for the Jinja environment.
#:
#: .. versionadded:: 0.11
jinja_environment = Environment
#: The class that is used for the :data:`~flask.g` instance.
#:
#: Example use cases for a custom class:
#:
#: 1. Store arbitrary attributes on flask.g.
#: 2. Add a property for lazy per-request database connectors.
#: 3. Return None instead of AttributeError on unexpected attributes.
#: 4. Raise exception if an unexpected attr is set, a "controlled" flask.g.
#:
#: In Flask 0.9 this property was called `request_globals_class` but it
#: was changed in 0.10 to :attr:`app_ctx_globals_class` because the
#: flask.g object is now application context scoped.
#:
#: .. versionadded:: 0.10
app_ctx_globals_class = _AppCtxGlobals
#: The class that is used for the ``config`` attribute of this app.
#: Defaults to :class:`~flask.Config`.
#:
#: Example use cases for a custom class:
#:
#: 1. Default values for certain config options.
#: 2. Access to config values through attributes in addition to keys.
#:
#: .. versionadded:: 0.11
config_class = Config
#: The testing flag. Set this to ``True`` to enable the test mode of
#: Flask extensions (and in the future probably also Flask itself).
#: For example this might activate test helpers that have an
#: additional runtime cost which should not be enabled by default.
#:
#: If this is enabled and PROPAGATE_EXCEPTIONS is not changed from the
#: default it's implicitly enabled.
#:
#: This attribute can also be configured from the config with the
#: ``TESTING`` configuration key. Defaults to ``False``.
testing = ConfigAttribute("TESTING")
#: If a secret key is set, cryptographic components can use this to
#: sign cookies and other things. Set this to a complex random value
#: when you want to use the secure cookie for instance.
#:
#: This attribute can also be configured from the config with the
#: :data:`SECRET_KEY` configuration key. Defaults to ``None``.
secret_key = ConfigAttribute("SECRET_KEY")
#: The secure cookie uses this for the name of the session cookie.
#:
#: This attribute can also be configured from the config with the
#: ``SESSION_COOKIE_NAME`` configuration key. Defaults to ``'session'``
session_cookie_name = ConfigAttribute("SESSION_COOKIE_NAME")
#: A :class:`~datetime.timedelta` which is used to set the expiration
#: date of a permanent session. The default is 31 days which makes a
#: permanent session survive for roughly one month.
#:
#: This attribute can also be configured from the config with the
#: ``PERMANENT_SESSION_LIFETIME`` configuration key. Defaults to
#: ``timedelta(days=31)``
permanent_session_lifetime = ConfigAttribute(
"PERMANENT_SESSION_LIFETIME", get_converter=_make_timedelta
)
#: A :class:`~datetime.timedelta` or number of seconds which is used
#: as the default ``max_age`` for :func:`send_file`. The default is
#: ``None``, which tells the browser to use conditional requests
#: instead of a timed cache.
#:
#: Configured with the :data:`SEND_FILE_MAX_AGE_DEFAULT`
#: configuration key.
#:
#: .. versionchanged:: 2.0
#: Defaults to ``None`` instead of 12 hours.
send_file_max_age_default = ConfigAttribute(
"SEND_FILE_MAX_AGE_DEFAULT", get_converter=_make_timedelta
)
#: Enable this if you want to use the X-Sendfile feature. Keep in
#: mind that the server has to support this. This only affects files
#: sent with the :func:`send_file` method.
#:
#: .. versionadded:: 0.2
#:
#: This attribute can also be configured from the config with the
#: ``USE_X_SENDFILE`` configuration key. Defaults to ``False``.
use_x_sendfile = ConfigAttribute("USE_X_SENDFILE")
#: The JSON encoder class to use. Defaults to :class:`~flask.json.JSONEncoder`.
#:
#: .. versionadded:: 0.10
json_encoder = json.JSONEncoder
#: The JSON decoder class to use. Defaults to :class:`~flask.json.JSONDecoder`.
#:
#: .. versionadded:: 0.10
json_decoder = json.JSONDecoder
#: Options that are passed to the Jinja environment in
#: :meth:`create_jinja_environment`. Changing these options after
#: the environment is created (accessing :attr:`jinja_env`) will
#: have no effect.
#:
#: .. versionchanged:: 1.1.0
#: This is a ``dict`` instead of an ``ImmutableDict`` to allow
#: easier configuration.
#:
jinja_options = {"extensions": ["jinja2.ext.autoescape", "jinja2.ext.with_"]}
#: Default configuration parameters.
default_config = ImmutableDict(
{
"ENV": None,
"DEBUG": None,
"TESTING": False,
"PROPAGATE_EXCEPTIONS": None,
"PRESERVE_CONTEXT_ON_EXCEPTION": None,
"SECRET_KEY": None,
"PERMANENT_SESSION_LIFETIME": timedelta(days=31),
"USE_X_SENDFILE": False,
"SERVER_NAME": None,
"APPLICATION_ROOT": "/",
"SESSION_COOKIE_NAME": "session",
"SESSION_COOKIE_DOMAIN": None,
"SESSION_COOKIE_PATH": None,
"SESSION_COOKIE_HTTPONLY": True,
"SESSION_COOKIE_SECURE": False,
"SESSION_COOKIE_SAMESITE": None,
"SESSION_REFRESH_EACH_REQUEST": True,
"MAX_CONTENT_LENGTH": None,
"SEND_FILE_MAX_AGE_DEFAULT": None,
"TRAP_BAD_REQUEST_ERRORS": None,
"TRAP_HTTP_EXCEPTIONS": False,
"EXPLAIN_TEMPLATE_LOADING": False,
"PREFERRED_URL_SCHEME": "http",
"JSON_AS_ASCII": True,
"JSON_SORT_KEYS": True,
"JSONIFY_PRETTYPRINT_REGULAR": False,
"JSONIFY_MIMETYPE": "application/json",
"TEMPLATES_AUTO_RELOAD": None,
"MAX_COOKIE_SIZE": 4093,
}
)
#: The rule object to use for URL rules created. This is used by
#: :meth:`add_url_rule`. Defaults to :class:`werkzeug.routing.Rule`.
#:
#: .. versionadded:: 0.7
url_rule_class = Rule
#: The map object to use for storing the URL rules and routing
#: configuration parameters. Defaults to :class:`werkzeug.routing.Map`.
#:
#: .. versionadded:: 1.1.0
url_map_class = Map
#: the test client that is used with when `test_client` is used.
#:
#: .. versionadded:: 0.7
test_client_class = None
#: The :class:`~click.testing.CliRunner` subclass, by default
#: :class:`~flask.testing.FlaskCliRunner` that is used by
#: :meth:`test_cli_runner`. Its ``__init__`` method should take a
#: Flask app object as the first argument.
#:
#: .. versionadded:: 1.0
test_cli_runner_class = None
#: the session interface to use. By default an instance of
#: :class:`~flask.sessions.SecureCookieSessionInterface` is used here.
#:
#: .. versionadded:: 0.8
session_interface = SecureCookieSessionInterface()
# TODO remove the next three attrs when Sphinx :inherited-members: works
# https://github.com/sphinx-doc/sphinx/issues/741
#: The name of the package or module that this app belongs to. Do not
#: change this once it is set by the constructor.
import_name = None
#: Location of the template files to be added to the template lookup.
#: ``None`` if templates should not be added.
template_folder = None
#: Absolute path to the package on the filesystem. Used to look up
#: resources contained in the package.
root_path = None
def __init__(
self,
import_name,
static_url_path=None,
static_folder="static",
static_host=None,
host_matching=False,
subdomain_matching=False,
template_folder="templates",
instance_path=None,
instance_relative_config=False,
root_path=None,
):
super().__init__(
import_name=import_name,
static_folder=static_folder,
static_url_path=static_url_path,
template_folder=template_folder,
root_path=root_path,
)
if instance_path is None:
instance_path = self.auto_find_instance_path()
elif not os.path.isabs(instance_path):
raise ValueError(
"If an instance path is provided it must be absolute."
" A relative path was given instead."
)
#: Holds the path to the instance folder.
#:
#: .. versionadded:: 0.8
self.instance_path = instance_path
#: The configuration dictionary as :class:`Config`. This behaves
#: exactly like a regular dictionary but supports additional methods
#: to load a config from files.
self.config = self.make_config(instance_relative_config)
#: A list of functions that are called when :meth:`url_for` raises a
#: :exc:`~werkzeug.routing.BuildError`. Each function registered here
#: is called with `error`, `endpoint` and `values`. If a function
#: returns ``None`` or raises a :exc:`BuildError` the next function is
#: tried.
#:
#: .. versionadded:: 0.9
self.url_build_error_handlers = []
#: A list of functions that will be called at the beginning of the
#: first request to this instance. To register a function, use the
#: :meth:`before_first_request` decorator.
#:
#: .. versionadded:: 0.8
self.before_first_request_funcs = []
#: A list of functions that are called when the application context
#: is destroyed. Since the application context is also torn down
#: if the request ends this is the place to store code that disconnects
#: from databases.
#:
#: .. versionadded:: 0.9
self.teardown_appcontext_funcs = []
#: A list of shell context processor functions that should be run
#: when a shell context is created.
#:
#: .. versionadded:: 0.11
self.shell_context_processors = []
#: all the attached blueprints in a dictionary by name. Blueprints
#: can be attached multiple times so this dictionary does not tell
#: you how often they got attached.
#:
#: .. versionadded:: 0.7
self.blueprints = {}
self._blueprint_order = []
#: a place where extensions can store application specific state. For
#: example this is where an extension could store database engines and
#: similar things.
#:
#: The key must match the name of the extension module. For example in
#: case of a "Flask-Foo" extension in `flask_foo`, the key would be
#: ``'foo'``.
#:
#: .. versionadded:: 0.7
self.extensions = {}
#: The :class:`~werkzeug.routing.Map` for this instance. You can use
#: this to change the routing converters after the class was created
#: but before any routes are connected. Example::
#:
#: from werkzeug.routing import BaseConverter
#:
#: class ListConverter(BaseConverter):
#: def to_python(self, value):
#: return value.split(',')
#: def to_url(self, values):
#: return ','.join(super(ListConverter, self).to_url(value)
#: for value in values)
#:
#: app = Flask(__name__)
#: app.url_map.converters['list'] = ListConverter
self.url_map = self.url_map_class()
self.url_map.host_matching = host_matching
self.subdomain_matching = subdomain_matching
# tracks internally if the application already handled at least one
# request.
self._got_first_request = False
self._before_request_lock = Lock()
# Add a static route using the provided static_url_path, static_host,
# and static_folder if there is a configured static_folder.
# Note we do this without checking if static_folder exists.
# For one, it might be created while the server is running (e.g. during
# development). Also, Google App Engine stores static files somewhere
if self.has_static_folder:
assert (
bool(static_host) == host_matching
), "Invalid static_host/host_matching combination"
# Use a weakref to avoid creating a reference cycle between the app
# and the view function (see #3761).
self_ref = weakref.ref(self)
self.add_url_rule(
f"{self.static_url_path}/<path:filename>",
endpoint="static",
host=static_host,
view_func=lambda **kw: self_ref().send_static_file(**kw),
)
# Set the name of the Click group in case someone wants to add
# the app's commands to another CLI tool.
self.cli.name = self.name
def _is_setup_finished(self):
return self.debug and self._got_first_request
@locked_cached_property
def name(self):
"""The name of the application. This is usually the import name
with the difference that it's guessed from the run file if the
import name is main. This name is used as a display name when
Flask needs the name of the application. It can be set and overridden
to change the value.
.. versionadded:: 0.8
"""
if self.import_name == "__main__":
fn = getattr(sys.modules["__main__"], "__file__", None)
if fn is None:
return "__main__"
return os.path.splitext(os.path.basename(fn))[0]
return self.import_name
@property
def propagate_exceptions(self):
"""Returns the value of the ``PROPAGATE_EXCEPTIONS`` configuration
value in case it's set, otherwise a sensible default is returned.
.. versionadded:: 0.7
"""
rv = self.config["PROPAGATE_EXCEPTIONS"]
if rv is not None:
return rv
return self.testing or self.debug
@property
def preserve_context_on_exception(self):
"""Returns the value of the ``PRESERVE_CONTEXT_ON_EXCEPTION``
configuration value in case it's set, otherwise a sensible default
is returned.
.. versionadded:: 0.7
"""
rv = self.config["PRESERVE_CONTEXT_ON_EXCEPTION"]
if rv is not None:
return rv
return self.debug
@locked_cached_property
def logger(self):
"""A standard Python :class:`~logging.Logger` for the app, with
the same name as :attr:`name`.
In debug mode, the logger's :attr:`~logging.Logger.level` will
be set to :data:`~logging.DEBUG`.
If there are no handlers configured, a default handler will be
added. See :doc:`/logging` for more information.
.. versionchanged:: 1.1.0
The logger takes the same name as :attr:`name` rather than
hard-coding ``"flask.app"``.
.. versionchanged:: 1.0.0
Behavior was simplified. The logger is always named
``"flask.app"``. The level is only set during configuration,
it doesn't check ``app.debug`` each time. Only one format is
used, not different ones depending on ``app.debug``. No
handlers are removed, and a handler is only added if no
handlers are already configured.
.. versionadded:: 0.3
"""
return create_logger(self)
@locked_cached_property
def jinja_env(self):
"""The Jinja environment used to load templates.
The environment is created the first time this property is
accessed. Changing :attr:`jinja_options` after that will have no
effect.
"""
return self.create_jinja_environment()
@property
def got_first_request(self):
"""This attribute is set to ``True`` if the application started
handling the first request.
.. versionadded:: 0.8
"""
return self._got_first_request
def make_config(self, instance_relative=False):
"""Used to create the config attribute by the Flask constructor.
The `instance_relative` parameter is passed in from the constructor
of Flask (there named `instance_relative_config`) and indicates if
the config should be relative to the instance path or the root path
of the application.
.. versionadded:: 0.8
"""
root_path = self.root_path
if instance_relative:
root_path = self.instance_path
defaults = dict(self.default_config)
defaults["ENV"] = get_env()
defaults["DEBUG"] = get_debug_flag()
return self.config_class(root_path, defaults)
def auto_find_instance_path(self):
"""Tries to locate the instance path if it was not provided to the
constructor of the application class. It will basically calculate
the path to a folder named ``instance`` next to your main file or
the package.
.. versionadded:: 0.8
"""
prefix, package_path = find_package(self.import_name)
if prefix is None:
return os.path.join(package_path, "instance")
return os.path.join(prefix, "var", f"{self.name}-instance")
def open_instance_resource(self, resource, mode="rb"):
"""Opens a resource from the application's instance folder
(:attr:`instance_path`). Otherwise works like
:meth:`open_resource`. Instance resources can also be opened for
writing.
:param resource: the name of the resource. To access resources within
subfolders use forward slashes as separator.
:param mode: resource file opening mode, default is 'rb'.
"""
return open(os.path.join(self.instance_path, resource), mode)
@property
def templates_auto_reload(self):
"""Reload templates when they are changed. Used by
:meth:`create_jinja_environment`.
This attribute can be configured with :data:`TEMPLATES_AUTO_RELOAD`. If
not set, it will be enabled in debug mode.
.. versionadded:: 1.0
This property was added but the underlying config and behavior
already existed.
"""
rv = self.config["TEMPLATES_AUTO_RELOAD"]
return rv if rv is not None else self.debug
@templates_auto_reload.setter
def templates_auto_reload(self, value):
self.config["TEMPLATES_AUTO_RELOAD"] = value
def create_jinja_environment(self):
"""Create the Jinja environment based on :attr:`jinja_options`
and the various Jinja-related methods of the app. Changing
:attr:`jinja_options` after this will have no effect. Also adds
Flask-related globals and filters to the environment.
.. versionchanged:: 0.11
``Environment.auto_reload`` set in accordance with
``TEMPLATES_AUTO_RELOAD`` configuration option.
.. versionadded:: 0.5
"""
options = dict(self.jinja_options)
if "autoescape" not in options:
options["autoescape"] = self.select_jinja_autoescape
if "auto_reload" not in options:
options["auto_reload"] = self.templates_auto_reload
rv = self.jinja_environment(self, **options)
rv.globals.update(
url_for=url_for,
get_flashed_messages=get_flashed_messages,
config=self.config,
# request, session and g are normally added with the
# context processor for efficiency reasons but for imported
# templates we also want the proxies in there.
request=request,
session=session,
g=g,
)
rv.filters["tojson"] = json.tojson_filter
return rv
def create_global_jinja_loader(self):
"""Creates the loader for the Jinja2 environment. Can be used to
override just the loader and keeping the rest unchanged. It's
discouraged to override this function. Instead one should override
the :meth:`jinja_loader` function instead.
The global loader dispatches between the loaders of the application
and the individual blueprints.
.. versionadded:: 0.7
"""
return DispatchingJinjaLoader(self)
def select_jinja_autoescape(self, filename):
"""Returns ``True`` if autoescaping should be active for the given
template name. If no template name is given, returns `True`.
.. versionadded:: 0.5
"""
if filename is None:
return True
return filename.endswith((".html", ".htm", ".xml", ".xhtml"))
def update_template_context(self, context):
"""Update the template context with some commonly used variables.
This injects request, session, config and g into the template
context as well as everything template context processors want
to inject. Note that the as of Flask 0.6, the original values
in the context will not be overridden if a context processor
decides to return a value with the same key.
:param context: the context as a dictionary that is updated in place
to add extra variables.
"""
funcs = self.template_context_processors[None]
reqctx = _request_ctx_stack.top
if reqctx is not None:
bp = reqctx.request.blueprint
if bp is not None and bp in self.template_context_processors:
funcs = chain(funcs, self.template_context_processors[bp])
orig_ctx = context.copy()
for func in funcs:
context.update(func())
# make sure the original values win. This makes it possible to
# easier add new variables in context processors without breaking
# existing views.
context.update(orig_ctx)
def make_shell_context(self):
"""Returns the shell context for an interactive shell for this
application. This runs all the registered shell context
processors.
.. versionadded:: 0.11
"""
rv = {"app": self, "g": g}
for processor in self.shell_context_processors:
rv.update(processor())
return rv
#: What environment the app is running in. Flask and extensions may
#: enable behaviors based on the environment, such as enabling debug
#: mode. This maps to the :data:`ENV` config key. This is set by the
#: :envvar:`FLASK_ENV` environment variable and may not behave as
#: expected if set in code.
#:
#: **Do not enable development when deploying in production.**
#:
#: Default: ``'production'``
env = ConfigAttribute("ENV")
@property
def debug(self):
"""Whether debug mode is enabled. When using ``flask run`` to start
the development server, an interactive debugger will be shown for
unhandled exceptions, and the server will be reloaded when code
changes. This maps to the :data:`DEBUG` config key. This is
enabled when :attr:`env` is ``'development'`` and is overridden
by the ``FLASK_DEBUG`` environment variable. It may not behave as
expected if set in code.
**Do not enable debug mode when deploying in production.**
Default: ``True`` if :attr:`env` is ``'development'``, or
``False`` otherwise.
"""
return self.config["DEBUG"]
@debug.setter
def debug(self, value):
self.config["DEBUG"] = value
self.jinja_env.auto_reload = self.templates_auto_reload
def run(self, host=None, port=None, debug=None, load_dotenv=True, **options):
"""Runs the application on a local development server.
Do not use ``run()`` in a production setting. It is not intended to
meet security and performance requirements for a production server.
Instead, see :doc:`/deploying/index` for WSGI server recommendations.
If the :attr:`debug` flag is set the server will automatically reload
for code changes and show a debugger in case an exception happened.
If you want to run the application in debug mode, but disable the
code execution on the interactive debugger, you can pass
``use_evalex=False`` as parameter. This will keep the debugger's
traceback screen active, but disable code execution.
It is not recommended to use this function for development with
automatic reloading as this is badly supported. Instead you should
be using the :command:`flask` command line script's ``run`` support.
.. admonition:: Keep in Mind
Flask will suppress any server error with a generic error page
unless it is in debug mode. As such to enable just the
interactive debugger without the code reloading, you have to
invoke :meth:`run` with ``debug=True`` and ``use_reloader=False``.
Setting ``use_debugger`` to ``True`` without being in debug mode
won't catch any exceptions because there won't be any to
catch.
:param host: the hostname to listen on. Set this to ``'0.0.0.0'`` to
have the server available externally as well. Defaults to
``'127.0.0.1'`` or the host in the ``SERVER_NAME`` config variable
if present.
:param port: the port of the webserver. Defaults to ``5000`` or the
port defined in the ``SERVER_NAME`` config variable if present.
:param debug: if given, enable or disable debug mode. See
:attr:`debug`.
:param load_dotenv: Load the nearest :file:`.env` and :file:`.flaskenv`
files to set environment variables. Will also change the working
directory to the directory containing the first file found.
:param options: the options to be forwarded to the underlying Werkzeug
server. See :func:`werkzeug.serving.run_simple` for more
information.
.. versionchanged:: 1.0
If installed, python-dotenv will be used to load environment
variables from :file:`.env` and :file:`.flaskenv` files.
If set, the :envvar:`FLASK_ENV` and :envvar:`FLASK_DEBUG`
environment variables will override :attr:`env` and
:attr:`debug`.
Threaded mode is enabled by default.
.. versionchanged:: 0.10
The default port is now picked from the ``SERVER_NAME``
variable.
"""
# Change this into a no-op if the server is invoked from the
# command line. Have a look at cli.py for more information.
if os.environ.get("FLASK_RUN_FROM_CLI") == "true":
from .debughelpers import explain_ignored_app_run
explain_ignored_app_run()
return
if get_load_dotenv(load_dotenv):
cli.load_dotenv()
# if set, let env vars override previous values
if "FLASK_ENV" in os.environ:
self.env = get_env()
self.debug = get_debug_flag()
elif "FLASK_DEBUG" in os.environ:
self.debug = get_debug_flag()
# debug passed to method overrides all other sources
if debug is not None:
self.debug = bool(debug)
server_name = self.config.get("SERVER_NAME")
sn_host = sn_port = None
if server_name:
sn_host, _, sn_port = server_name.partition(":")
if not host:
if sn_host:
host = sn_host
else:
host = "127.0.0.1"
if port or port == 0:
port = int(port)
elif sn_port:
port = int(sn_port)
else:
port = 5000
options.setdefault("use_reloader", self.debug)
options.setdefault("use_debugger", self.debug)
options.setdefault("threaded", True)
cli.show_server_banner(self.env, self.debug, self.name, False)
from werkzeug.serving import run_simple
try:
run_simple(host, port, self, **options)
finally:
# reset the first request information if the development server
# reset normally. This makes it possible to restart the server
# without reloader and that stuff from an interactive shell.
self._got_first_request = False
def test_client(self, use_cookies=True, **kwargs):
"""Creates a test client for this application. For information
about unit testing head over to :doc:`/testing`.
Note that if you are testing for assertions or exceptions in your
application code, you must set ``app.testing = True`` in order for the
exceptions to propagate to the test client. Otherwise, the exception
will be handled by the application (not visible to the test client) and
the only indication of an AssertionError or other exception will be a
500 status code response to the test client. See the :attr:`testing`
attribute. For example::
app.testing = True
client = app.test_client()
The test client can be used in a ``with`` block to defer the closing down
of the context until the end of the ``with`` block. This is useful if
you want to access the context locals for testing::
with app.test_client() as c:
rv = c.get('/?vodka=42')
assert request.args['vodka'] == '42'
Additionally, you may pass optional keyword arguments that will then
be passed to the application's :attr:`test_client_class` constructor.
For example::
from flask.testing import FlaskClient
class CustomClient(FlaskClient):
def __init__(self, *args, **kwargs):
self._authentication = kwargs.pop("authentication")
super(CustomClient,self).__init__( *args, **kwargs)
app.test_client_class = CustomClient
client = app.test_client(authentication='Basic ....')
See :class:`~flask.testing.FlaskClient` for more information.
.. versionchanged:: 0.4
added support for ``with`` block usage for the client.
.. versionadded:: 0.7
The `use_cookies` parameter was added as well as the ability
to override the client to be used by setting the
:attr:`test_client_class` attribute.
.. versionchanged:: 0.11
Added `**kwargs` to support passing additional keyword arguments to
the constructor of :attr:`test_client_class`.
"""
cls = self.test_client_class
if cls is None:
from .testing import FlaskClient as cls
return cls(self, self.response_class, use_cookies=use_cookies, **kwargs)
def test_cli_runner(self, **kwargs):
"""Create a CLI runner for testing CLI commands.
See :ref:`testing-cli`.
Returns an instance of :attr:`test_cli_runner_class`, by default
:class:`~flask.testing.FlaskCliRunner`. The Flask app object is
passed as the first argument.
.. versionadded:: 1.0
"""
cls = self.test_cli_runner_class
if cls is None:
from .testing import FlaskCliRunner as cls
return cls(self, **kwargs)
@setupmethod
def register_blueprint(self, blueprint, **options):
"""Register a :class:`~flask.Blueprint` on the application. Keyword
arguments passed to this method will override the defaults set on the
blueprint.
Calls the blueprint's :meth:`~flask.Blueprint.register` method after
recording the blueprint in the application's :attr:`blueprints`.
:param blueprint: The blueprint to register.
:param url_prefix: Blueprint routes will be prefixed with this.
:param subdomain: Blueprint routes will match on this subdomain.
:param url_defaults: Blueprint routes will use these default values for
view arguments.
:param options: Additional keyword arguments are passed to
:class:`~flask.blueprints.BlueprintSetupState`. They can be
accessed in :meth:`~flask.Blueprint.record` callbacks.
.. versionadded:: 0.7
"""
first_registration = False
if blueprint.name in self.blueprints:
assert self.blueprints[blueprint.name] is blueprint, (
"A name collision occurred between blueprints"
f" {blueprint!r} and {self.blueprints[blueprint.name]!r}."
f" Both share the same name {blueprint.name!r}."
f" Blueprints that are created on the fly need unique"
f" names."
)
else:
self.blueprints[blueprint.name] = blueprint
self._blueprint_order.append(blueprint)