JezK
Edit File: app.py
import functools import inspect import json import logging import os import sys import typing as t import weakref from collections.abc import Iterator as _abc_Iterator from datetime import timedelta from itertools import chain from threading import Lock from types import TracebackType import click from werkzeug.datastructures import Headers from werkzeug.datastructures import ImmutableDict from werkzeug.exceptions import Aborter 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 MapAdapter from werkzeug.routing import RequestRedirect from werkzeug.routing import RoutingException from werkzeug.routing import Rule from werkzeug.serving import is_running_from_reloader from werkzeug.urls import url_quote from werkzeug.utils import redirect as _wz_redirect from werkzeug.wrappers import Response as BaseResponse from . import cli from . import typing as ft from .config import Config from .config import ConfigAttribute from .ctx import _AppCtxGlobals from .ctx import AppContext from .ctx import RequestContext from .globals import _cv_app from .globals import _cv_request from .globals import g from .globals import request from .globals import request_ctx from .globals import session from .helpers import _split_blueprint_path from .helpers import get_debug_flag from .helpers import get_flashed_messages from .helpers import get_load_dotenv from .helpers import locked_cached_property from .json.provider import DefaultJSONProvider from .json.provider import JSONProvider from .logging import create_logger from .scaffold import _endpoint_from_view_func from .scaffold import _sentinel from .scaffold import find_package from .scaffold import Scaffold from .scaffold import setupmethod from .sessions import SecureCookieSessionInterface from .sessions import SessionInterface 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 if t.TYPE_CHECKING: # pragma: no cover import typing_extensions as te from .blueprints import Blueprint from .testing import FlaskClient from .testing import FlaskCliRunner T_before_first_request = t.TypeVar( "T_before_first_request", bound=ft.BeforeFirstRequestCallable ) T_shell_context_processor = t.TypeVar( "T_shell_context_processor", bound=ft.ShellContextProcessorCallable ) T_teardown = t.TypeVar("T_teardown", bound=ft.TeardownCallable) T_template_filter = t.TypeVar("T_template_filter", bound=ft.TemplateFilterCallable) T_template_global = t.TypeVar("T_template_global", bound=ft.TemplateGlobalCallable) T_template_test = t.TypeVar("T_template_test", bound=ft.TemplateTestCallable) if sys.version_info >= (3, 8): iscoroutinefunction = inspect.iscoroutinefunction else: def iscoroutinefunction(func: t.Any) -> bool: while inspect.ismethod(func): func = func.__func__ while isinstance(func, functools.partial): func = func.func return inspect.iscoroutinefunction(func) def _make_timedelta(value: t.Union[timedelta, int, None]) -> t.Optional[timedelta]: 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 of the object assigned to :attr:`aborter`, created by #: :meth:`create_aborter`. That object is called by #: :func:`flask.abort` to raise HTTP errors, and can be #: called directly as well. #: #: Defaults to :class:`werkzeug.exceptions.Aborter`. #: #: .. versionadded:: 2.2 aborter_class = Aborter #: 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") @property def session_cookie_name(self) -> str: """The name of the cookie set by the session interface. .. deprecated:: 2.2 Will be removed in Flask 2.3. Use ``app.config["SESSION_COOKIE_NAME"]`` instead. """ import warnings warnings.warn( "'session_cookie_name' is deprecated and will be removed in Flask 2.3. Use" " 'SESSION_COOKIE_NAME' in 'app.config' instead.", DeprecationWarning, stacklevel=2, ) return self.config["SESSION_COOKIE_NAME"] @session_cookie_name.setter def session_cookie_name(self, value: str) -> None: import warnings warnings.warn( "'session_cookie_name' is deprecated and will be removed in Flask 2.3. Use" " 'SESSION_COOKIE_NAME' in 'app.config' instead.", DeprecationWarning, stacklevel=2, ) self.config["SESSION_COOKIE_NAME"] = value #: 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 ) @property def send_file_max_age_default(self) -> t.Optional[timedelta]: """The default value for ``max_age`` for :func:`~flask.send_file`. The default is ``None``, which tells the browser to use conditional requests instead of a timed cache. .. deprecated:: 2.2 Will be removed in Flask 2.3. Use ``app.config["SEND_FILE_MAX_AGE_DEFAULT"]`` instead. .. versionchanged:: 2.0 Defaults to ``None`` instead of 12 hours. """ import warnings warnings.warn( "'send_file_max_age_default' is deprecated and will be removed in Flask" " 2.3. Use 'SEND_FILE_MAX_AGE_DEFAULT' in 'app.config' instead.", DeprecationWarning, stacklevel=2, ) return _make_timedelta(self.config["SEND_FILE_MAX_AGE_DEFAULT"]) @send_file_max_age_default.setter def send_file_max_age_default(self, value: t.Union[int, timedelta, None]) -> None: import warnings warnings.warn( "'send_file_max_age_default' is deprecated and will be removed in Flask" " 2.3. Use 'SEND_FILE_MAX_AGE_DEFAULT' in 'app.config' instead.", DeprecationWarning, stacklevel=2, ) self.config["SEND_FILE_MAX_AGE_DEFAULT"] = _make_timedelta(value) @property def use_x_sendfile(self) -> bool: """Enable this to use the ``X-Sendfile`` feature, assuming the server supports it, from :func:`~flask.send_file`. .. deprecated:: 2.2 Will be removed in Flask 2.3. Use ``app.config["USE_X_SENDFILE"]`` instead. """ import warnings warnings.warn( "'use_x_sendfile' is deprecated and will be removed in Flask 2.3. Use" " 'USE_X_SENDFILE' in 'app.config' instead.", DeprecationWarning, stacklevel=2, ) return self.config["USE_X_SENDFILE"] @use_x_sendfile.setter def use_x_sendfile(self, value: bool) -> None: import warnings warnings.warn( "'use_x_sendfile' is deprecated and will be removed in Flask 2.3. Use" " 'USE_X_SENDFILE' in 'app.config' instead.", DeprecationWarning, stacklevel=2, ) self.config["USE_X_SENDFILE"] = value _json_encoder: t.Union[t.Type[json.JSONEncoder], None] = None _json_decoder: t.Union[t.Type[json.JSONDecoder], None] = None @property # type: ignore[override] def json_encoder(self) -> t.Type[json.JSONEncoder]: # type: ignore[override] """The JSON encoder class to use. Defaults to :class:`~flask.json.JSONEncoder`. .. deprecated:: 2.2 Will be removed in Flask 2.3. Customize :attr:`json_provider_class` instead. .. versionadded:: 0.10 """ import warnings warnings.warn( "'app.json_encoder' is deprecated and will be removed in Flask 2.3." " Customize 'app.json_provider_class' or 'app.json' instead.", DeprecationWarning, stacklevel=2, ) if self._json_encoder is None: from . import json return json.JSONEncoder return self._json_encoder @json_encoder.setter def json_encoder(self, value: t.Type[json.JSONEncoder]) -> None: import warnings warnings.warn( "'app.json_encoder' is deprecated and will be removed in Flask 2.3." " Customize 'app.json_provider_class' or 'app.json' instead.", DeprecationWarning, stacklevel=2, ) self._json_encoder = value @property # type: ignore[override] def json_decoder(self) -> t.Type[json.JSONDecoder]: # type: ignore[override] """The JSON decoder class to use. Defaults to :class:`~flask.json.JSONDecoder`. .. deprecated:: 2.2 Will be removed in Flask 2.3. Customize :attr:`json_provider_class` instead. .. versionadded:: 0.10 """ import warnings warnings.warn( "'app.json_decoder' is deprecated and will be removed in Flask 2.3." " Customize 'app.json_provider_class' or 'app.json' instead.", DeprecationWarning, stacklevel=2, ) if self._json_decoder is None: from . import json return json.JSONDecoder return self._json_decoder @json_decoder.setter def json_decoder(self, value: t.Type[json.JSONDecoder]) -> None: import warnings warnings.warn( "'app.json_decoder' is deprecated and will be removed in Flask 2.3." " Customize 'app.json_provider_class' or 'app.json' instead.", DeprecationWarning, stacklevel=2, ) self._json_decoder = value json_provider_class: t.Type[JSONProvider] = DefaultJSONProvider """A subclass of :class:`~flask.json.provider.JSONProvider`. An instance is created and assigned to :attr:`app.json` when creating the app. The default, :class:`~flask.json.provider.DefaultJSONProvider`, uses Python's built-in :mod:`json` library. A different provider can use a different JSON library. .. versionadded:: 2.2 """ #: 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: dict = {} #: Default configuration parameters. default_config = ImmutableDict( { "ENV": None, "DEBUG": None, "TESTING": False, "PROPAGATE_EXCEPTIONS": 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": None, "JSON_SORT_KEYS": None, "JSONIFY_PRETTYPRINT_REGULAR": None, "JSONIFY_MIMETYPE": None, "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 :meth:`test_client` method creates an instance of this test #: client class. Defaults to :class:`~flask.testing.FlaskClient`. #: #: .. versionadded:: 0.7 test_client_class: t.Optional[t.Type["FlaskClient"]] = 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: t.Optional[t.Type["FlaskCliRunner"]] = None #: the session interface to use. By default an instance of #: :class:`~flask.sessions.SecureCookieSessionInterface` is used here. #: #: .. versionadded:: 0.8 session_interface: SessionInterface = SecureCookieSessionInterface() def __init__( self, import_name: str, static_url_path: t.Optional[str] = None, static_folder: t.Optional[t.Union[str, os.PathLike]] = "static", static_host: t.Optional[str] = None, host_matching: bool = False, subdomain_matching: bool = False, template_folder: t.Optional[str] = "templates", instance_path: t.Optional[str] = None, instance_relative_config: bool = False, root_path: t.Optional[str] = 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) #: An instance of :attr:`aborter_class` created by #: :meth:`make_aborter`. This is called by :func:`flask.abort` #: to raise HTTP errors, and can be called directly as well. #: #: .. versionadded:: 2.2 #: Moved from ``flask.abort``, which calls this object. self.aborter = self.make_aborter() self.json: JSONProvider = self.json_provider_class(self) """Provides access to JSON methods. Functions in ``flask.json`` will call methods on this provider when the application context is active. Used for handling JSON requests and responses. An instance of :attr:`json_provider_class`. Can be customized by changing that attribute on a subclass, or by assigning to this attribute afterwards. The default, :class:`~flask.json.provider.DefaultJSONProvider`, uses Python's built-in :mod:`json` library. A different provider can use a different JSON library. .. versionadded:: 2.2 """ #: A list of functions that are called by #: :meth:`handle_url_build_error` when :meth:`.url_for` raises a #: :exc:`~werkzeug.routing.BuildError`. Each function is called #: with ``error``, ``endpoint`` and ``values``. If a function #: returns ``None`` or raises a ``BuildError``, it is skipped. #: Otherwise, its return value is returned by ``url_for``. #: #: .. versionadded:: 0.9 self.url_build_error_handlers: t.List[ t.Callable[[Exception, str, t.Dict[str, t.Any]], str] ] = [] #: 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. #: #: .. deprecated:: 2.2 #: Will be removed in Flask 2.3. Run setup code when #: creating the application instead. #: #: .. versionadded:: 0.8 self.before_first_request_funcs: t.List[ft.BeforeFirstRequestCallable] = [] #: 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: t.List[ft.TeardownCallable] = [] #: A list of shell context processor functions that should be run #: when a shell context is created. #: #: .. versionadded:: 0.11 self.shell_context_processors: t.List[ft.ShellContextProcessorCallable] = [] #: Maps registered blueprint names to blueprint objects. The #: dict retains the order the blueprints were registered in. #: Blueprints can be registered multiple times, this dict does #: not track how often they were attached. #: #: .. versionadded:: 0.7 self.blueprints: t.Dict[str, "Blueprint"] = {} #: 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: dict = {} #: 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), # type: ignore # noqa: B950 ) # 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 _check_setup_finished(self, f_name: str) -> None: if self._got_first_request: raise AssertionError( f"The setup method '{f_name}' can no longer be called" " on the application. It has already handled its first" " request, any changes will not be applied" " consistently.\n" "Make sure all imports, decorators, functions, etc." " needed to set up the application are done before" " running it." ) @locked_cached_property def name(self) -> str: # type: ignore """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) -> bool: """Returns the value of the ``PROPAGATE_EXCEPTIONS`` configuration value in case it's set, otherwise a sensible default is returned. .. deprecated:: 2.2 Will be removed in Flask 2.3. .. versionadded:: 0.7 """ import warnings warnings.warn( "'propagate_exceptions' is deprecated and will be removed in Flask 2.3.", DeprecationWarning, stacklevel=2, ) rv = self.config["PROPAGATE_EXCEPTIONS"] if rv is not None: return rv return self.testing or self.debug @locked_cached_property def logger(self) -> logging.Logger: """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) -> Environment: """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) -> bool: """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: bool = False) -> Config: """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"] = os.environ.get("FLASK_ENV") or "production" defaults["DEBUG"] = get_debug_flag() return self.config_class(root_path, defaults) def make_aborter(self) -> Aborter: """Create the object to assign to :attr:`aborter`. That object is called by :func:`flask.abort` to raise HTTP errors, and can be called directly as well. By default, this creates an instance of :attr:`aborter_class`, which defaults to :class:`werkzeug.exceptions.Aborter`. .. versionadded:: 2.2 """ return self.aborter_class() def auto_find_instance_path(self) -> str: """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: str, mode: str = "rb") -> t.IO[t.AnyStr]: """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) -> bool: """Reload templates when they are changed. Used by :meth:`create_jinja_environment`. It is enabled by default in debug mode. .. deprecated:: 2.2 Will be removed in Flask 2.3. Use ``app.config["TEMPLATES_AUTO_RELOAD"]`` instead. .. versionadded:: 1.0 This property was added but the underlying config and behavior already existed. """ import warnings warnings.warn( "'templates_auto_reload' is deprecated and will be removed in Flask 2.3." " Use 'TEMPLATES_AUTO_RELOAD' in 'app.config' instead.", DeprecationWarning, stacklevel=2, ) 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: bool) -> None: import warnings warnings.warn( "'templates_auto_reload' is deprecated and will be removed in Flask 2.3." " Use 'TEMPLATES_AUTO_RELOAD' in 'app.config' instead.", DeprecationWarning, stacklevel=2, ) self.config["TEMPLATES_AUTO_RELOAD"] = value def create_jinja_environment(self) -> Environment: """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: auto_reload = self.config["TEMPLATES_AUTO_RELOAD"] if auto_reload is None: auto_reload = self.debug options["auto_reload"] = auto_reload rv = self.jinja_environment(self, **options) rv.globals.update( url_for=self.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.policies["json.dumps_function"] = self.json.dumps return rv def create_global_jinja_loader(self) -> DispatchingJinjaLoader: """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: str) -> bool: """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: dict) -> None: """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. """ names: t.Iterable[t.Optional[str]] = (None,) # A template may be rendered outside a request context. if request: names = chain(names, reversed(request.blueprints)) # The values passed to render_template take precedence. Keep a # copy to re-apply after all context functions. orig_ctx = context.copy() for name in names: if name in self.template_context_processors: for func in self.template_context_processors[name]: context.update(func()) context.update(orig_ctx) def make_shell_context(self) -> dict: """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 @property def env(self) -> str: """What environment the app is running in. This maps to the :data:`ENV` config key. **Do not enable development when deploying in production.** Default: ``'production'`` .. deprecated:: 2.2 Will be removed in Flask 2.3. """ import warnings warnings.warn( "'app.env' is deprecated and will be removed in Flask 2.3." " Use 'app.debug' instead.", DeprecationWarning, stacklevel=2, ) return self.config["ENV"] @env.setter def env(self, value: str) -> None: import warnings warnings.warn( "'app.env' is deprecated and will be removed in Flask 2.3." " Use 'app.debug' instead.", DeprecationWarning, stacklevel=2, ) self.config["ENV"] = value @property def debug(self) -> bool: """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. It may not behave as expected if set late. **Do not enable debug mode when deploying in production.** Default: ``False`` """ return self.config["DEBUG"] @debug.setter def debug(self, value: bool) -> None: self.config["DEBUG"] = value if self.config["TEMPLATES_AUTO_RELOAD"] is None: self.jinja_env.auto_reload = value def run( self, host: t.Optional[str] = None, port: t.Optional[int] = None, debug: t.Optional[bool] = None, load_dotenv: bool = True, **options: t.Any, ) -> None: """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. The :envvar:`FLASK_DEBUG` environment variable will override :attr:`debug`. Threaded mode is enabled by default. .. versionchanged:: 0.10 The default port is now picked from the ``SERVER_NAME`` variable. """ # Ignore this call so that it doesn't start another server if # the 'flask run' command is used. if os.environ.get("FLASK_RUN_FROM_CLI") == "true": if not is_running_from_reloader(): click.secho( " * Ignoring a call to 'app.run()' that would block" " the current 'flask' CLI command.\n" " Only call 'app.run()' in an 'if __name__ ==" ' "__main__"\' guard.', fg="red", ) return if get_load_dotenv(load_dotenv): cli.load_dotenv() # if set, let env vars override previous values if "FLASK_ENV" in os.environ: print( "'FLASK_ENV' is deprecated and will not be used in" " Flask 2.3. Use 'FLASK_DEBUG' instead.", file=sys.stderr, ) self.config["ENV"] = os.environ.get("FLASK_ENV") or "production" 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.debug, self.name) from werkzeug.serving import run_simple try: run_simple(t.cast(str, 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: bool = True, **kwargs: t.Any) -> "FlaskClient": """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 # type: ignore return cls( # type: ignore self, self.response_class, use_cookies=use_cookies, **kwargs ) def test_cli_runner(self, **kwargs: t.Any) -> "FlaskCliRunner": """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 # type: ignore return cls(self, **kwargs) # type: ignore @setupmethod def register_blueprint(self, blueprint: "Blueprint", **options: t.Any) -> None: """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. .. versionchanged:: 2.0.1 The ``name`` option can be used to change the (pre-dotted) name the blueprint is registered with. This allows the same blueprint to be registered multiple times with unique names for ``url_for``. .. versionadded:: 0.7 """ blueprint.register(self, options) def iter_blueprints(self) -> t.ValuesView["Blueprint"]: """Iterates over all blueprints by the order they were registered. .. versionadded:: 0.11 """ return self.blueprints.values() @setupmethod def add_url_rule( self, rule: str, endpoint: t.Optional[str] = None, view_func: t.Optional[ft.RouteCallable] = None, provide_automatic_options: t.Optional[bool] = None, **options: t.Any, ) -> None: if endpoint is None: endpoint = _endpoint_from_view_func(view_func) # type: ignore options["endpoint"] = endpoint methods = options.pop("methods", None) # if the methods are not given and the view_func object knows its # methods we can use that instead. If neither exists, we go with # a tuple of only ``GET`` as default. if methods is None: methods = getattr(view_func, "methods", None) or ("GET",) if isinstance(methods, str): raise TypeError( "Allowed methods must be a list of strings, for" ' example: @app.route(..., methods=["POST"])' ) methods = {item.upper() for item in methods} # Methods that should always be added required_methods = set(getattr(view_func, "required_methods", ())) # starting with Flask 0.8 the view_func object can disable and # force-enable the automatic options handling. if provide_automatic_options is None: provide_automatic_options = getattr( view_func, "provide_automatic_options", None ) if provide_automatic_options is None: if "OPTIONS" not in methods: provide_automatic_options = True required_methods.add("OPTIONS") else: provide_automatic_options = False # Add the required methods now. methods |= required_methods rule = self.url_rule_class(rule, methods=methods, **options) rule.provide_automatic_options = provide_automatic_options # type: ignore self.url_map.add(rule) if view_func is not None: old_func = self.view_functions.get(endpoint) if old_func is not None and old_func != view_func: raise AssertionError( "View function mapping is overwriting an existing" f" endpoint function: {endpoint}" ) self.view_functions[endpoint] = view_func @setupmethod def template_filter( self, name: t.Optional[str] = None ) -> t.Callable[[T_template_filter], T_template_filter]: """A decorator that is used to register custom template filter. You can specify a name for the filter, otherwise the function name will be used. Example:: @app.template_filter() def reverse(s): return s[::-1] :param name: the optional name of the filter, otherwise the function name will be used. """ def decorator(f: T_template_filter) -> T_template_filter: self.add_template_filter(f, name=name) return f return decorator @setupmethod def add_template_filter( self, f: ft.TemplateFilterCallable, name: t.Optional[str] = None ) -> None: """Register a custom template filter. Works exactly like the :meth:`template_filter` decorator. :param name: the optional name of the filter, otherwise the function name will be used. """ self.jinja_env.filters[name or f.__name__] = f @setupmethod def template_test( self, name: t.Optional[str] = None ) -> t.Callable[[T_template_test], T_template_test]: """A decorator that is used to register custom template test. You can specify a name for the test, otherwise the function name will be used. Example:: @app.template_test() def is_prime(n): if n == 2: return True for i in range(2, int(math.ceil(math.sqrt(n))) + 1): if n % i == 0: return False return True .. versionadded:: 0.10 :param name: the optional name of the test, otherwise the function name will be used. """ def decorator(f: T_template_test) -> T_template_test: self.add_template_test(f, name=name) return f return decorator @setupmethod def add_template_test( self, f: ft.TemplateTestCallable, name: t.Optional[str] = None ) -> None: """Register a custom template test. Works exactly like the :meth:`template_test` decorator. .. versionadded:: 0.10 :param name: the optional name of the test, otherwise the function name will be used. """ self.jinja_env.tests[name or f.__name__] = f @setupmethod def template_global( self, name: t.Optional[str] = None ) -> t.Callable[[T_template_global], T_template_global]: """A decorator that is used to register a custom template global function. You can specify a name for the global function, otherwise the function name will be used. Example:: @app.template_global() def double(n): return 2 * n .. versionadded:: 0.10 :param name: the optional name of the global function, otherwise the function name will be used. """ def decorator(f: T_template_global) -> T_template_global: self.add_template_global(f, name=name) return f return decorator @setupmethod def add_template_global( self, f: ft.TemplateGlobalCallable, name: t.Optional[str] = None ) -> None: """Register a custom template global function. Works exactly like the :meth:`template_global` decorator. .. versionadded:: 0.10 :param name: the optional name of the global function, otherwise the function name will be used. """ self.jinja_env.globals[name or f.__name__] = f @setupmethod def before_first_request(self, f: T_before_first_request) -> T_before_first_request: """Registers a function to be run before the first request to this instance of the application. The function will be called without any arguments and its return value is ignored. .. deprecated:: 2.2 Will be removed in Flask 2.3. Run setup code when creating the application instead. .. versionadded:: 0.8 """ import warnings warnings.warn( "'before_first_request' is deprecated and will be removed" " in Flask 2.3. Run setup code while creating the" " application instead.", DeprecationWarning, stacklevel=2, ) self.before_first_request_funcs.append(f) return f @setupmethod def teardown_appcontext(self, f: T_teardown) -> T_teardown: """Registers a function to be called when the application context is popped. The application context is typically popped after the request context for each request, at the end of CLI commands, or after a manually pushed context ends. .. code-block:: python with app.app_context(): ... When the ``with`` block exits (or ``ctx.pop()`` is called), the teardown functions are called just before the app context is made inactive. Since a request context typically also manages an application context it would also be called when you pop a request context. When a teardown function was called because of an unhandled exception it will be passed an error object. If an :meth:`errorhandler` is registered, it will handle the exception and the teardown will not receive it. Teardown functions must avoid raising exceptions. If they execute code that might fail they must surround that code with a ``try``/``except`` block and log any errors. The return values of teardown functions are ignored. .. versionadded:: 0.9 """ self.teardown_appcontext_funcs.append(f) return f @setupmethod def shell_context_processor( self, f: T_shell_context_processor ) -> T_shell_context_processor: """Registers a shell context processor function. .. versionadded:: 0.11 """ self.shell_context_processors.append(f) return f def _find_error_handler(self, e: Exception) -> t.Optional[ft.ErrorHandlerCallable]: """Return a registered error handler for an exception in this order: blueprint handler for a specific code, app handler for a specific code, blueprint handler for an exception class, app handler for an exception class, or ``None`` if a suitable handler is not found. """ exc_class, code = self._get_exc_class_and_code(type(e)) names = (*request.blueprints, None) for c in (code, None) if code is not None else (None,): for name in names: handler_map = self.error_handler_spec[name][c] if not handler_map: continue for cls in exc_class.__mro__: handler = handler_map.get(cls) if handler is not None: return handler return None def handle_http_exception( self, e: HTTPException ) -> t.Union[HTTPException, ft.ResponseReturnValue]: """Handles an HTTP exception. By default this will invoke the registered error handlers and fall back to returning the exception as response. .. versionchanged:: 1.0.3 ``RoutingException``, used internally for actions such as slash redirects during routing, is not passed to error handlers. .. versionchanged:: 1.0 Exceptions are looked up by code *and* by MRO, so ``HTTPException`` subclasses can be handled with a catch-all handler for the base ``HTTPException``. .. versionadded:: 0.3 """ # Proxy exceptions don't have error codes. We want to always return # those unchanged as errors if e.code is None: return e # RoutingExceptions are used internally to trigger routing # actions, such as slash redirects raising RequestRedirect. They # are not raised or handled in user code. if isinstance(e, RoutingException): return e handler = self._find_error_handler(e) if handler is None: return e return self.ensure_sync(handler)(e) def trap_http_exception(self, e: Exception) -> bool: """Checks if an HTTP exception should be trapped or not. By default this will return ``False`` for all exceptions except for a bad request key error if ``TRAP_BAD_REQUEST_ERRORS`` is set to ``True``. It also returns ``True`` if ``TRAP_HTTP_EXCEPTIONS`` is set to ``True``. This is called for all HTTP exceptions raised by a view function. If it returns ``True`` for any exception the error handler for this exception is not called and it shows up as regular exception in the traceback. This is helpful for debugging implicitly raised HTTP exceptions. .. versionchanged:: 1.0 Bad request errors are not trapped by default in debug mode. .. versionadded:: 0.8 """ if self.config["TRAP_HTTP_EXCEPTIONS"]: return True trap_bad_request = self.config["TRAP_BAD_REQUEST_ERRORS"] # if unset, trap key errors in debug mode if ( trap_bad_request is None and self.debug and isinstance(e, BadRequestKeyError) ): return True if trap_bad_request: return isinstance(e, BadRequest) return False def handle_user_exception( self, e: Exception ) -> t.Union[HTTPException, ft.ResponseReturnValue]: """This method is called whenever an exception occurs that should be handled. A special case is :class:`~werkzeug .exceptions.HTTPException` which is forwarded to the :meth:`handle_http_exception` method. This function will either return a response value or reraise the exception with the same traceback. .. versionchanged:: 1.0 Key errors raised from request data like ``form`` show the bad key in debug mode rather than a generic bad request message. .. versionadded:: 0.7 """ if isinstance(e, BadRequestKeyError) and ( self.debug or self.config["TRAP_BAD_REQUEST_ERRORS"] ): e.show_exception = True if isinstance(e, HTTPException) and not self.trap_http_exception(e): return self.handle_http_exception(e) handler = self._find_error_handler(e) if handler is None: raise return self.ensure_sync(handler)(e) def handle_exception(self, e: Exception) -> Response: """Handle an exception that did not have an error handler associated with it, or that was raised from an error handler. This always causes a 500 ``InternalServerError``. Always sends the :data:`got_request_exception` signal. If :attr:`propagate_exceptions` is ``True``, such as in debug mode, the error will be re-raised so that the debugger can display it. Otherwise, the original exception is logged, and an :exc:`~werkzeug.exceptions.InternalServerError` is returned. If an error handler is registered for ``InternalServerError`` or ``500``, it will be used. For consistency, the handler will always receive the ``InternalServerError``. The original unhandled exception is available as ``e.original_exception``. .. versionchanged:: 1.1.0 Always passes the ``InternalServerError`` instance to the handler, setting ``original_exception`` to the unhandled error. .. versionchanged:: 1.1.0 ``after_request`` functions and other finalization is done even for the default 500 response when there is no handler. .. versionadded:: 0.3 """ exc_info = sys.exc_info() got_request_exception.send(self, exception=e) propagate = self.config["PROPAGATE_EXCEPTIONS"] if propagate is None: propagate = self.testing or self.debug if propagate: # Re-raise if called with an active exception, otherwise # raise the passed in exception. if exc_info[1] is e: raise raise e self.log_exception(exc_info) server_error: t.Union[InternalServerError, ft.ResponseReturnValue] server_error = InternalServerError(original_exception=e) handler = self._find_error_handler(server_error) if handler is not None: server_error = self.ensure_sync(handler)(server_error) return self.finalize_request(server_error, from_error_handler=True) def log_exception( self, exc_info: t.Union[ t.Tuple[type, BaseException, TracebackType], t.Tuple[None, None, None] ], ) -> None: """Logs an exception. This is called by :meth:`handle_exception` if debugging is disabled and right before the handler is called. The default implementation logs the exception as error on the :attr:`logger`. .. versionadded:: 0.8 """ self.logger.error( f"Exception on {request.path} [{request.method}]", exc_info=exc_info ) def raise_routing_exception(self, request: Request) -> "te.NoReturn": """Intercept routing exceptions and possibly do something else. In debug mode, intercept a routing redirect and replace it with an error if the body will be discarded. With modern Werkzeug this shouldn't occur, since it now uses a 308 status which tells the browser to resend the method and body. .. versionchanged:: 2.1 Don't intercept 307 and 308 redirects. :meta private: :internal: """ if ( not self.debug or not isinstance(request.routing_exception, RequestRedirect) or request.routing_exception.code in {307, 308} or request.method in {"GET", "HEAD", "OPTIONS"} ): raise request.routing_exception # type: ignore from .debughelpers import FormDataRoutingRedirect raise FormDataRoutingRedirect(request) def dispatch_request(self) -> ft.ResponseReturnValue: """Does the request dispatching. Matches the URL and returns the return value of the view or error handler. This does not have to be a response object. In order to convert the return value to a proper response object, call :func:`make_response`. .. versionchanged:: 0.7 This no longer does the exception handling, this code was moved to the new :meth:`full_dispatch_request`. """ req = request_ctx.request if req.routing_exception is not None: self.raise_routing_exception(req) rule: Rule = req.url_rule # type: ignore[assignment] # if we provide automatic options for this URL and the # request came with the OPTIONS method, reply automatically if ( getattr(rule, "provide_automatic_options", False) and req.method == "OPTIONS" ): return self.make_default_options_response() # otherwise dispatch to the handler for that endpoint view_args: t.Dict[str, t.Any] = req.view_args # type: ignore[assignment] return self.ensure_sync(self.view_functions[rule.endpoint])(**view_args) def full_dispatch_request(self) -> Response: """Dispatches the request and on top of that performs request pre and postprocessing as well as HTTP exception catching and error handling. .. versionadded:: 0.7 """ # Run before_first_request functions if this is the thread's first request. # Inlined to avoid a method call on subsequent requests. # This is deprecated, will be removed in Flask 2.3. if not self._got_first_request: with self._before_request_lock: if not self._got_first_request: for func in self.before_first_request_funcs: self.ensure_sync(func)() self._got_first_request = True try: request_started.send(self) rv = self.preprocess_request() if rv is None: rv = self.dispatch_request() except Exception as e: rv = self.handle_user_exception(e) return self.finalize_request(rv) def finalize_request( self, rv: t.Union[ft.ResponseReturnValue, HTTPException], from_error_handler: bool = False, ) -> Response: """Given the return value from a view function this finalizes the request by converting it into a response and invoking the postprocessing functions. This is invoked for both normal request dispatching as well as error handlers. Because this means that it might be called as a result of a failure a special safe mode is available which can be enabled with the `from_error_handler` flag. If enabled, failures in response processing will be logged and otherwise ignored. :internal: """ response = self.make_response(rv) try: response = self.process_response(response) request_finished.send(self, response=response) except Exception: if not from_error_handler: raise self.logger.exception( "Request finalizing failed with an error while handling an error" ) return response def make_default_options_response(self) -> Response: """This method is called to create the default ``OPTIONS`` response. This can be changed through subclassing to change the default behavior of ``OPTIONS`` responses. .. versionadded:: 0.7 """ adapter = request_ctx.url_adapter methods = adapter.allowed_methods() # type: ignore[union-attr] rv = self.response_class() rv.allow.update(methods) return rv def should_ignore_error(self, error: t.Optional[BaseException]) -> bool: """This is called to figure out if an error should be ignored or not as far as the teardown system is concerned. If this function returns ``True`` then the teardown handlers will not be passed the error. .. versionadded:: 0.10 """ return False def ensure_sync(self, func: t.Callable) -> t.Callable: """Ensure that the function is synchronous for WSGI workers. Plain ``def`` functions are returned as-is. ``async def`` functions are wrapped to run and wait for the response. Override this method to change how the app runs async views. .. versionadded:: 2.0 """ if iscoroutinefunction(func): return self.async_to_sync(func) return func def async_to_sync( self, func: t.Callable[..., t.Coroutine] ) -> t.Callable[..., t.Any]: """Return a sync function that will run the coroutine function. .. code-block:: python result = app.async_to_sync(func)(*args, **kwargs) Override this method to change how the app converts async code to be synchronously callable. .. versionadded:: 2.0 """ try: from asgiref.sync import async_to_sync as asgiref_async_to_sync except ImportError: raise RuntimeError( "Install Flask with the 'async' extra in order to use async views." ) from None return asgiref_async_to_sync(func) def url_for( self, endpoint: str, *, _anchor: t.Optional[str] = None, _method: t.Optional[str] = None, _scheme: t.Optional[str] = None, _external: t.Optional[bool] = None, **values: t.Any, ) -> str: """Generate a URL to the given endpoint with the given values. This is called by :func:`flask.url_for`, and can be called directly as well. An *endpoint* is the name of a URL rule, usually added with :meth:`@app.route() <route>`, and usually the same name as the view function. A route defined in a :class:`~flask.Blueprint` will prepend the blueprint's name separated by a ``.`` to the endpoint. In some cases, such as email messages, you want URLs to include the scheme and domain, like ``https://example.com/hello``. When not in an active request, URLs will be external by default, but this requires setting :data:`SERVER_NAME` so Flask knows what domain to use. :data:`APPLICATION_ROOT` and :data:`PREFERRED_URL_SCHEME` should also be configured as needed. This config is only used when not in an active request. Functions can be decorated with :meth:`url_defaults` to modify keyword arguments before the URL is built. If building fails for some reason, such as an unknown endpoint or incorrect values, the app's :meth:`handle_url_build_error` method is called. If that returns a string, that is returned, otherwise a :exc:`~werkzeug.routing.BuildError` is raised. :param endpoint: The endpoint name associated with the URL to generate. If this starts with a ``.``, the current blueprint name (if any) will be used. :param _anchor: If given, append this as ``#anchor`` to the URL. :param _method: If given, generate the URL associated with this method for the endpoint. :param _scheme: If given, the URL will have this scheme if it is external. :param _external: If given, prefer the URL to be internal (False) or require it to be external (True). External URLs include the scheme and domain. When not in an active request, URLs are external by default. :param values: Values to use for the variable parts of the URL rule. Unknown keys are appended as query string arguments, like ``?a=b&c=d``. .. versionadded:: 2.2 Moved from ``flask.url_for``, which calls this method. """ req_ctx = _cv_request.get(None) if req_ctx is not None: url_adapter = req_ctx.url_adapter blueprint_name = req_ctx.request.blueprint # If the endpoint starts with "." and the request matches a # blueprint, the endpoint is relative to the blueprint. if endpoint[:1] == ".": if blueprint_name is not None: endpoint = f"{blueprint_name}{endpoint}" else: endpoint = endpoint[1:] # When in a request, generate a URL without scheme and # domain by default, unless a scheme is given. if _external is None: _external = _scheme is not None else: app_ctx = _cv_app.get(None) # If called by helpers.url_for, an app context is active, # use its url_adapter. Otherwise, app.url_for was called # directly, build an adapter. if app_ctx is not None: url_adapter = app_ctx.url_adapter else: url_adapter = self.create_url_adapter(None) if url_adapter is None: raise RuntimeError( "Unable to build URLs outside an active request" " without 'SERVER_NAME' configured. Also configure" " 'APPLICATION_ROOT' and 'PREFERRED_URL_SCHEME' as" " needed." ) # When outside a request, generate a URL with scheme and # domain by default. if _external is None: _external = True # It is an error to set _scheme when _external=False, in order # to avoid accidental insecure URLs. if _scheme is not None and not _external: raise ValueError("When specifying '_scheme', '_external' must be True.") self.inject_url_defaults(endpoint, values) try: rv = url_adapter.build( # type: ignore[union-attr] endpoint, values, method=_method, url_scheme=_scheme, force_external=_external, ) except BuildError as error: values.update( _anchor=_anchor, _method=_method, _scheme=_scheme, _external=_external ) return self.handle_url_build_error(error, endpoint, values) if _anchor is not None: rv = f"{rv}#{url_quote(_anchor)}" return rv def redirect(self, location: str, code: int = 302) -> BaseResponse: """Create a redirect response object. This is called by :func:`flask.redirect`, and can be called directly as well. :param location: The URL to redirect to. :param code: The status code for the redirect. .. versionadded:: 2.2 Moved from ``flask.redirect``, which calls this method. """ return _wz_redirect(location, code=code, Response=self.response_class) def make_response(self, rv: ft.ResponseReturnValue) -> Response: """Convert the return value from a view function to an instance of :attr:`response_class`. :param rv: the return value from the view function. The view function must return a response. Returning ``None``, or the view ending without returning, is not allowed. The following types are allowed for ``view_rv``: ``str`` A response object is created with the string encoded to UTF-8 as the body. ``bytes`` A response object is created with the bytes as the body. ``dict`` A dictionary that will be jsonify'd before being returned. ``list`` A list that will be jsonify'd before being returned. ``generator`` or ``iterator`` A generator that returns ``str`` or ``bytes`` to be streamed as the response. ``tuple`` Either ``(body, status, headers)``, ``(body, status)``, or ``(body, headers)``, where ``body`` is any of the other types allowed here, ``status`` is a string or an integer, and ``headers`` is a dictionary or a list of ``(key, value)`` tuples. If ``body`` is a :attr:`response_class` instance, ``status`` overwrites the exiting value and ``headers`` are extended. :attr:`response_class` The object is returned unchanged. other :class:`~werkzeug.wrappers.Response` class The object is coerced to :attr:`response_class`. :func:`callable` The function is called as a WSGI application. The result is used to create a response object. .. versionchanged:: 2.2 A generator will be converted to a streaming response. A list will be converted to a JSON response. .. versionchanged:: 1.1 A dict will be converted to a JSON response. .. versionchanged:: 0.9 Previously a tuple was interpreted as the arguments for the response object. """ status = headers = None # unpack tuple returns if isinstance(rv, tuple): len_rv = len(rv) # a 3-tuple is unpacked directly if len_rv == 3: rv, status, headers = rv # type: ignore[misc] # decide if a 2-tuple has status or headers elif len_rv == 2: if isinstance(rv[1], (Headers, dict, tuple, list)): rv, headers = rv else: rv, status = rv # type: ignore[assignment,misc] # other sized tuples are not allowed else: raise TypeError( "The view function did not return a valid response tuple." " The tuple must have the form (body, status, headers)," " (body, status), or (body, headers)." ) # the body must not be None if rv is None: raise TypeError( f"The view function for {request.endpoint!r} did not" " return a valid response. The function either returned" " None or ended without a return statement." ) # make sure the body is an instance of the response class if not isinstance(rv, self.response_class): if isinstance(rv, (str, bytes, bytearray)) or isinstance(rv, _abc_Iterator): # let the response class set the status and headers instead of # waiting to do it manually, so that the class can handle any # special logic rv = self.response_class( rv, status=status, headers=headers, # type: ignore[arg-type] ) status = headers = None elif isinstance(rv, (dict, list)): rv = self.json.response(rv) elif isinstance(rv, BaseResponse) or callable(rv): # evaluate a WSGI callable, or coerce a different response # class to the correct type try: rv = self.response_class.force_type( rv, request.environ # type: ignore[arg-type] ) except TypeError as e: raise TypeError( f"{e}\nThe view function did not return a valid" " response. The return type must be a string," " dict, list, tuple with headers or status," " Response instance, or WSGI callable, but it" f" was a {type(rv).__name__}." ).with_traceback(sys.exc_info()[2]) from None else: raise TypeError( "The view function did not return a valid" " response. The return type must be a string," " dict, list, tuple with headers or status," " Response instance, or WSGI callable, but it was a" f" {type(rv).__name__}." ) rv = t.cast(Response, rv) # prefer the status if it was provided if status is not None: if isinstance(status, (str, bytes, bytearray)): rv.status = status else: rv.status_code = status # extend existing headers with provided headers if headers: rv.headers.update(headers) # type: ignore[arg-type] return rv def create_url_adapter( self, request: t.Optional[Request] ) -> t.Optional[MapAdapter]: """Creates a URL adapter for the given request. The URL adapter is created at a point where the request context is not yet set up so the request is passed explicitly. .. versionadded:: 0.6 .. versionchanged:: 0.9 This can now also be called without a request object when the URL adapter is created for the application context. .. versionchanged:: 1.0 :data:`SERVER_NAME` no longer implicitly enables subdomain matching. Use :attr:`subdomain_matching` instead. """ if request is not None: # If subdomain matching is disabled (the default), use the # default subdomain in all cases. This should be the default # in Werkzeug but it currently does not have that feature. if not self.subdomain_matching: subdomain = self.url_map.default_subdomain or None else: subdomain = None return self.url_map.bind_to_environ( request.environ, server_name=self.config["SERVER_NAME"], subdomain=subdomain, ) # We need at the very least the server name to be set for this # to work. if self.config["SERVER_NAME"] is not None: return self.url_map.bind( self.config["SERVER_NAME"], script_name=self.config["APPLICATION_ROOT"], url_scheme=self.config["PREFERRED_URL_SCHEME"], ) return None def inject_url_defaults(self, endpoint: str, values: dict) -> None: """Injects the URL defaults for the given endpoint directly into the values dictionary passed. This is used internally and automatically called on URL building. .. versionadded:: 0.7 """ names: t.Iterable[t.Optional[str]] = (None,) # url_for may be called outside a request context, parse the # passed endpoint instead of using request.blueprints. if "." in endpoint: names = chain( names, reversed(_split_blueprint_path(endpoint.rpartition(".")[0])) ) for name in names: if name in self.url_default_functions: for func in self.url_default_functions[name]: func(endpoint, values) def handle_url_build_error( self, error: BuildError, endpoint: str, values: t.Dict[str, t.Any] ) -> str: """Called by :meth:`.url_for` if a :exc:`~werkzeug.routing.BuildError` was raised. If this returns a value, it will be returned by ``url_for``, otherwise the error will be re-raised. Each function in :attr:`url_build_error_handlers` is called with ``error``, ``endpoint`` and ``values``. If a function returns ``None`` or raises a ``BuildError``, it is skipped. Otherwise, its return value is returned by ``url_for``. :param error: The active ``BuildError`` being handled. :param endpoint: The endpoint being built. :param values: The keyword arguments passed to ``url_for``. """ for handler in self.url_build_error_handlers: try: rv = handler(error, endpoint, values) except BuildError as e: # make error available outside except block error = e else: if rv is not None: return rv # Re-raise if called with an active exception, otherwise raise # the passed in exception. if error is sys.exc_info()[1]: raise raise error def preprocess_request(self) -> t.Optional[ft.ResponseReturnValue]: """Called before the request is dispatched. Calls :attr:`url_value_preprocessors` registered with the app and the current blueprint (if any). Then calls :attr:`before_request_funcs` registered with the app and the blueprint. If any :meth:`before_request` handler returns a non-None value, the value is handled as if it was the return value from the view, and further request handling is stopped. """ names = (None, *reversed(request.blueprints)) for name in names: if name in self.url_value_preprocessors: for url_func in self.url_value_preprocessors[name]: url_func(request.endpoint, request.view_args) for name in names: if name in self.before_request_funcs: for before_func in self.before_request_funcs[name]: rv = self.ensure_sync(before_func)() if rv is not None: return rv return None def process_response(self, response: Response) -> Response: """Can be overridden in order to modify the response object before it's sent to the WSGI server. By default this will call all the :meth:`after_request` decorated functions. .. versionchanged:: 0.5 As of Flask 0.5 the functions registered for after request execution are called in reverse order of registration. :param response: a :attr:`response_class` object. :return: a new response object or the same, has to be an instance of :attr:`response_class`. """ ctx = request_ctx._get_current_object() # type: ignore[attr-defined] for func in ctx._after_request_functions: response = self.ensure_sync(func)(response) for name in chain(request.blueprints, (None,)): if name in self.after_request_funcs: for func in reversed(self.after_request_funcs[name]): response = self.ensure_sync(func)(response) if not self.session_interface.is_null_session(ctx.session): self.session_interface.save_session(self, ctx.session, response) return response def do_teardown_request( self, exc: t.Optional[BaseException] = _sentinel # type: ignore ) -> None: """Called after the request is dispatched and the response is returned, right before the request context is popped. This calls all functions decorated with :meth:`teardown_request`, and :meth:`Blueprint.teardown_request` if a blueprint handled the request. Finally, the :data:`request_tearing_down` signal is sent. This is called by :meth:`RequestContext.pop() <flask.ctx.RequestContext.pop>`, which may be delayed during testing to maintain access to resources. :param exc: An unhandled exception raised while dispatching the request. Detected from the current exception information if not passed. Passed to each teardown function. .. versionchanged:: 0.9 Added the ``exc`` argument. """ if exc is _sentinel: exc = sys.exc_info()[1] for name in chain(request.blueprints, (None,)): if name in self.teardown_request_funcs: for func in reversed(self.teardown_request_funcs[name]): self.ensure_sync(func)(exc) request_tearing_down.send(self, exc=exc) def do_teardown_appcontext( self, exc: t.Optional[BaseException] = _sentinel # type: ignore ) -> None: """Called right before the application context is popped. When handling a request, the application context is popped after the request context. See :meth:`do_teardown_request`. This calls all functions decorated with :meth:`teardown_appcontext`. Then the :data:`appcontext_tearing_down` signal is sent. This is called by :meth:`AppContext.pop() <flask.ctx.AppContext.pop>`. .. versionadded:: 0.9 """ if exc is _sentinel: exc = sys.exc_info()[1] for func in reversed(self.teardown_appcontext_funcs): self.ensure_sync(func)(exc) appcontext_tearing_down.send(self, exc=exc) def app_context(self) -> AppContext: """Create an :class:`~flask.ctx.AppContext`. Use as a ``with`` block to push the context, which will make :data:`current_app` point at this application. An application context is automatically pushed by :meth:`RequestContext.push() <flask.ctx.RequestContext.push>` when handling a request, and when running a CLI command. Use this to manually create a context outside of these situations. :: with app.app_context(): init_db() See :doc:`/appcontext`. .. versionadded:: 0.9 """ return AppContext(self) def request_context(self, environ: dict) -> RequestContext: """Create a :class:`~flask.ctx.RequestContext` representing a WSGI environment. Use a ``with`` block to push the context, which will make :data:`request` point at this request. See :doc:`/reqcontext`. Typically you should not call this from your own code. A request context is automatically pushed by the :meth:`wsgi_app` when handling a request. Use :meth:`test_request_context` to create an environment and context instead of this method. :param environ: a WSGI environment """ return RequestContext(self, environ) def test_request_context(self, *args: t.Any, **kwargs: t.Any) -> RequestContext: """Create a :class:`~flask.ctx.RequestContext` for a WSGI environment created from the given values. This is mostly useful during testing, where you may want to run a function that uses request data without dispatching a full request. See :doc:`/reqcontext`. Use a ``with`` block to push the context, which will make :data:`request` point at the request for the created environment. :: with test_request_context(...): generate_report() When using the shell, it may be easier to push and pop the context manually to avoid indentation. :: ctx = app.test_request_context(...) ctx.push() ... ctx.pop() Takes the same arguments as Werkzeug's :class:`~werkzeug.test.EnvironBuilder`, with some defaults from the application. See the linked Werkzeug docs for most of the available arguments. Flask-specific behavior is listed here. :param path: URL path being requested. :param base_url: Base URL where the app is being served, which ``path`` is relative to. If not given, built from :data:`PREFERRED_URL_SCHEME`, ``subdomain``, :data:`SERVER_NAME`, and :data:`APPLICATION_ROOT`. :param subdomain: Subdomain name to append to :data:`SERVER_NAME`. :param url_scheme: Scheme to use instead of :data:`PREFERRED_URL_SCHEME`. :param data: The request body, either as a string or a dict of form keys and values. :param json: If given, this is serialized as JSON and passed as ``data``. Also defaults ``content_type`` to ``application/json``. :param args: other positional arguments passed to :class:`~werkzeug.test.EnvironBuilder`. :param kwargs: other keyword arguments passed to :class:`~werkzeug.test.EnvironBuilder`. """ from .testing import EnvironBuilder builder = EnvironBuilder(self, *args, **kwargs) try: return self.request_context(builder.get_environ()) finally: builder.close() def wsgi_app(self, environ: dict, start_response: t.Callable) -> t.Any: """The actual WSGI application. This is not implemented in :meth:`__call__` so that middlewares can be applied without losing a reference to the app object. Instead of doing this:: app = MyMiddleware(app) It's a better idea to do this instead:: app.wsgi_app = MyMiddleware(app.wsgi_app) Then you still have the original application object around and can continue to call methods on it. .. versionchanged:: 0.7 Teardown events for the request and app contexts are called even if an unhandled error occurs. Other events may not be called depending on when an error occurs during dispatch. See :ref:`callbacks-and-errors`. :param environ: A WSGI environment. :param start_response: A callable accepting a status code, a list of headers, and an optional exception context to start the response. """ ctx = self.request_context(environ) error: t.Optional[BaseException] = None try: try: ctx.push() response = self.full_dispatch_request() except Exception as e: error = e response = self.handle_exception(e) except: # noqa: B001 error = sys.exc_info()[1] raise return response(environ, start_response) finally: if "werkzeug.debug.preserve_context" in environ: environ["werkzeug.debug.preserve_context"](_cv_app.get()) environ["werkzeug.debug.preserve_context"](_cv_request.get()) if error is not None and self.should_ignore_error(error): error = None ctx.pop(error) def __call__(self, environ: dict, start_response: t.Callable) -> t.Any: """The WSGI server calls the Flask application object as the WSGI application. This calls :meth:`wsgi_app`, which can be wrapped to apply middleware. """ return self.wsgi_app(environ, start_response)