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Commit ff4a13ed authored by Vladislav Rykov's avatar Vladislav Rykov
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env/lib/python3.5/site-packages/flask/_compat.py 0 → 100644
View file @ ff4a13ed
# -*- coding: utf-8 -*-
"""
flask._compat
~~~~~~~~~~~~~
Some py2/py3 compatibility support based on a stripped down
version of six so we don't have to depend on a specific version
of it.
:copyright: 2010 Pallets
:license: BSD-3-Clause
"""
import sys
PY2 = sys.version_info[0] == 2
_identity = lambda x: x
try: # Python 2
text_type = unicode
string_types = (str, unicode)
integer_types = (int, long)
except NameError: # Python 3
text_type = str
string_types = (str,)
integer_types = (int,)
if not PY2:
iterkeys = lambda d: iter(d.keys())
itervalues = lambda d: iter(d.values())
iteritems = lambda d: iter(d.items())
from inspect import getfullargspec as getargspec
from io import StringIO
import collections.abc as collections_abc
def reraise(tp, value, tb=None):
if value.__traceback__ is not tb:
raise value.with_traceback(tb)
raise value
implements_to_string = _identity
else:
iterkeys = lambda d: d.iterkeys()
itervalues = lambda d: d.itervalues()
iteritems = lambda d: d.iteritems()
from inspect import getargspec
from cStringIO import StringIO
import collections as collections_abc
exec("def reraise(tp, value, tb=None):\n raise tp, value, tb")
def implements_to_string(cls):
cls.__unicode__ = cls.__str__
cls.__str__ = lambda x: x.__unicode__().encode("utf-8")
return cls
def with_metaclass(meta, *bases):
"""Create a base class with a metaclass."""
# This requires a bit of explanation: the basic idea is to make a
# dummy metaclass for one level of class instantiation that replaces
# itself with the actual metaclass.
class metaclass(type):
def __new__(metacls, name, this_bases, d):
return meta(name, bases, d)
return type.__new__(metaclass, "temporary_class", (), {})
# Certain versions of pypy have a bug where clearing the exception stack
# breaks the __exit__ function in a very peculiar way. The second level of
# exception blocks is necessary because pypy seems to forget to check if an
# exception happened until the next bytecode instruction?
#
# Relevant PyPy bugfix commit:
# https://bitbucket.org/pypy/pypy/commits/77ecf91c635a287e88e60d8ddb0f4e9df4003301
# According to ronan on #pypy IRC, it is released in PyPy2 2.3 and later
# versions.
#
# Ubuntu 14.04 has PyPy 2.2.1, which does exhibit this bug.
BROKEN_PYPY_CTXMGR_EXIT = False
if hasattr(sys, "pypy_version_info"):
class _Mgr(object):
def __enter__(self):
return self
def __exit__(self, *args):
if hasattr(sys, "exc_clear"):
# Python 3 (PyPy3) doesn't have exc_clear
sys.exc_clear()
try:
try:
with _Mgr():
raise AssertionError()
except: # noqa: B001
# We intentionally use a bare except here. See the comment above
# regarding a pypy bug as to why.
raise
except TypeError:
BROKEN_PYPY_CTXMGR_EXIT = True
except AssertionError:
pass
try:
from os import fspath
except ImportError:
# Backwards compatibility as proposed in PEP 0519:
# https://www.python.org/dev/peps/pep-0519/#backwards-compatibility
def fspath(path):
return path.__fspath__() if hasattr(path, "__fspath__") else path
class _DeprecatedBool(object):
def __init__(self, name, version, value):
self.message = "'{}' is deprecated and will be removed in version {}.".format(
name, version
)
self.value = value
def _warn(self):
import warnings
warnings.warn(self.message, DeprecationWarning, stacklevel=2)
def __eq__(self, other):
self._warn()
return other == self.value
def __ne__(self, other):
self._warn()
return other != self.value
def __bool__(self):
self._warn()
return self.value
__nonzero__ = __bool__
json_available = _DeprecatedBool("flask.json_available", "2.0.0", True)
env/lib/python3.5/site-packages/flask/app.py 0 → 100644
View file @ ff4a13ed
# -*- coding: utf-8 -*-
"""
flask.app
~~~~~~~~~
This module implements the central WSGI application object.
:copyright: 2010 Pallets
:license: BSD-3-Clause
"""
import os
import sys
import warnings
from datetime import timedelta
from functools import update_wrapper
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 default_exceptions
from werkzeug.exceptions import HTTPException
from werkzeug.exceptions import InternalServerError
from werkzeug.exceptions import MethodNotAllowed
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 ._compat import integer_types
from ._compat import reraise
from ._compat import string_types
from ._compat import text_type
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 _endpoint_from_view_func
from .helpers import _PackageBoundObject
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 .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 _default_template_ctx_processor
from .templating import DispatchingJinjaLoader
from .templating import Environment
from .wrappers import Request
from .wrappers import Response
# a singleton sentinel value for parameter defaults
_sentinel = object()
def _make_timedelta(value):
if not isinstance(value, timedelta):
return timedelta(seconds=value)
return value
def setupmethod(f):
"""Wraps a method so that it performs a check in debug mode if the
first request was already handled.
"""
def wrapper_func(self, *args, **kwargs):
if self.debug and self._got_first_request:
raise AssertionError(
"A setup function was called after the "
"first request was handled. This usually indicates a bug "
"in the application where a module was not imported "
"and decorators or other functionality was called too late.\n"
"To fix this make sure to import all your view modules, "
"database models and everything related at a central place "
"before the application starts serving requests."
)
return f(self, *args, **kwargs)
return update_wrapper(wrapper_func, f)
class Flask(_PackageBoundObject):
"""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: Flask by default will automatically calculate the path
to the root of the application. In certain situations
this cannot be achieved (for instance if the package
is a Python 3 namespace package) and needs to be
manually defined.
"""
#: 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` which is used as default cache_timeout
#: for the :func:`send_file` functions. The default is 12 hours.
#:
#: This attribute can also be configured from the config with the
#: ``SEND_FILE_MAX_AGE_DEFAULT`` configuration key. This configuration
#: variable can also be set with an integer value used as seconds.
#: Defaults to ``timedelta(hours=12)``
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": timedelta(hours=12),
"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,
):
_PackageBoundObject.__init__(
self, import_name, template_folder=template_folder, root_path=root_path
)
self.static_url_path = static_url_path
self.static_folder = static_folder
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 dictionary of all view functions registered. The keys will
#: be function names which are also used to generate URLs and
#: the values are the function objects themselves.
#: To register a view function, use the :meth:`route` decorator.
self.view_functions = {}
#: A dictionary of all registered error handlers. The key is ``None``
#: for error handlers active on the application, otherwise the key is
#: the name of the blueprint. Each key points to another dictionary
#: where the key is the status code of the http exception. The
#: special key ``None`` points to a list of tuples where the first item
#: is the class for the instance check and the second the error handler
#: function.
#:
#: To register an error handler, use the :meth:`errorhandler`
#: decorator.
self.error_handler_spec = {}
#: 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 dictionary with lists of functions that will be called at the
#: beginning of each request. The key of the dictionary is the name of
#: the blueprint this function is active for, or ``None`` for all
#: requests. To register a function, use the :meth:`before_request`
#: decorator.
self.before_request_funcs = {}
#: 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 dictionary with lists of functions that should be called after
#: each request. The key of the dictionary is the name of the blueprint
#: this function is active for, ``None`` for all requests. This can for
#: example be used to close database connections. To register a function
#: here, use the :meth:`after_request` decorator.
self.after_request_funcs = {}
#: A dictionary with lists of functions that are called after
#: each request, even if an exception has occurred. The key of the
#: dictionary is the name of the blueprint this function is active for,
#: ``None`` for all requests. These functions are not allowed to modify
#: the request, and their return values are ignored. If an exception
#: occurred while processing the request, it gets passed to each
#: teardown_request function. To register a function here, use the
#: :meth:`teardown_request` decorator.
#:
#: .. versionadded:: 0.7
self.teardown_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 dictionary with lists of functions that are called before the
#: :attr:`before_request_funcs` functions. The key of the dictionary is
#: the name of the blueprint this function is active for, or ``None``
#: for all requests. To register a function, use
#: :meth:`url_value_preprocessor`.
#:
#: .. versionadded:: 0.7
self.url_value_preprocessors = {}
#: A dictionary with lists of functions that can be used as URL value
#: preprocessors. The key ``None`` here is used for application wide
#: callbacks, otherwise the key is the name of the blueprint.
#: Each of these functions has the chance to modify the dictionary
#: of URL values before they are used as the keyword arguments of the
#: view function. For each function registered this one should also
#: provide a :meth:`url_defaults` function that adds the parameters
#: automatically again that were removed that way.
#:
#: .. versionadded:: 0.7
self.url_default_functions = {}
#: A dictionary with list of functions that are called without argument
#: to populate the template context. The key of the dictionary is the
#: name of the blueprint this function is active for, ``None`` for all
#: requests. Each returns a dictionary that the template context is
#: updated with. To register a function here, use the
#: :meth:`context_processor` decorator.
self.template_context_processors = {None: [_default_template_ctx_processor]}
#: 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. For backwards compatibility extensions should register
#: themselves like this::
#:
#: if not hasattr(app, 'extensions'):
#: app.extensions = {}
#: app.extensions['extensionname'] = SomeObject()
#:
#: 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"
self.add_url_rule(
self.static_url_path + "/<path:filename>",
endpoint="static",
host=static_host,
view_func=self.send_static_file,
)
# 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
@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", 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 :ref:`deployment` 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)
_host = "127.0.0.1"
_port = 5000
server_name = self.config.get("SERVER_NAME")
sn_host, sn_port = None, None
if server_name:
sn_host, _, sn_port = server_name.partition(":")
host = host or sn_host or _host
# pick the first value that's not None (0 is allowed)
port = int(next((p for p in (port, sn_port) if p is not None), _port))
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 :ref:`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)
def open_session(self, request):
"""Creates or opens a new session. Default implementation stores all
session data in a signed cookie. This requires that the
:attr:`secret_key` is set. Instead of overriding this method
we recommend replacing the :class:`session_interface`.
.. deprecated: 1.0
Will be removed in 2.0. Use
``session_interface.open_session`` instead.
:param request: an instance of :attr:`request_class`.
"""
warnings.warn(
DeprecationWarning(
'"open_session" is deprecated and will be removed in'
' 2.0. Use "session_interface.open_session" instead.'
)
)
return self.session_interface.open_session(self, request)
def save_session(self, session, response):
"""Saves the session if it needs updates. For the default
implementation, check :meth:`open_session`. Instead of overriding this
method we recommend replacing the :class:`session_interface`.
.. deprecated: 1.0
Will be removed in 2.0. Use
``session_interface.save_session`` instead.
:param session: the session to be saved (a
:class:`~werkzeug.contrib.securecookie.SecureCookie`
object)
:param response: an instance of :attr:`response_class`
"""
warnings.warn(
DeprecationWarning(
'"save_session" is deprecated and will be removed in'
' 2.0. Use "session_interface.save_session" instead.'
)
)
return self.session_interface.save_session(self, session, response)
def make_null_session(self):
"""Creates a new instance of a missing session. Instead of overriding
this method we recommend replacing the :class:`session_interface`.
.. deprecated: 1.0
Will be removed in 2.0. Use
``session_interface.make_null_session`` instead.
.. versionadded:: 0.7
"""
warnings.warn(
DeprecationWarning(
'"make_null_session" is deprecated and will be removed'
' in 2.0. Use "session_interface.make_null_session"'
" instead."
)
)
return self.session_interface.make_null_session(self)
@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 %r and %r. Both"
' share the same name "%s". Blueprints that are created on the'
" fly need unique names."
% (blueprint, self.blueprints[blueprint.name], blueprint.name)
)
else:
self.blueprints[blueprint.name] = blueprint
self._blueprint_order.append(blueprint)
first_registration = True
blueprint.register(self, options, first_registration)
def iter_blueprints(self):
"""Iterates over all blueprints by the order they were registered.
.. versionadded:: 0.11
"""
return iter(self._blueprint_order)
@setupmethod
def add_url_rule(
self,
rule,
endpoint=None,
view_func=None,
provide_automatic_options=None,
**options
):
"""Connects a URL rule. Works exactly like the :meth:`route`
decorator. If a view_func is provided it will be registered with the
endpoint.
Basically this example::
@app.route('/')
def index():
pass
Is equivalent to the following::
def index():
pass
app.add_url_rule('/', 'index', index)
If the view_func is not provided you will need to connect the endpoint
to a view function like so::
app.view_functions['index'] = index
Internally :meth:`route` invokes :meth:`add_url_rule` so if you want
to customize the behavior via subclassing you only need to change
this method.
For more information refer to :ref:`url-route-registrations`.
.. versionchanged:: 0.2
`view_func` parameter added.
.. versionchanged:: 0.6
``OPTIONS`` is added automatically as method.
:param rule: the URL rule as string
:param endpoint: the endpoint for the registered URL rule. Flask
itself assumes the name of the view function as
endpoint
:param view_func: the function to call when serving a request to the
provided endpoint
:param provide_automatic_options: controls whether the ``OPTIONS``
method should be added automatically. This can also be controlled
by setting the ``view_func.provide_automatic_options = False``
before adding the rule.
:param options: the options to be forwarded to the underlying
:class:`~werkzeug.routing.Rule` object. A change
to Werkzeug is handling of method options. methods
is a list of methods this rule should be limited
to (``GET``, ``POST`` etc.). By default a rule
just listens for ``GET`` (and implicitly ``HEAD``).
Starting with Flask 0.6, ``OPTIONS`` is implicitly
added and handled by the standard request handling.
"""
if endpoint is None:
endpoint = _endpoint_from_view_func(view_func)
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, string_types):
raise TypeError(
"Allowed methods have to be iterables of strings, "
'for example: @app.route(..., methods=["POST"])'
)
methods = set(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
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 endpoint function: %s" % endpoint
)
self.view_functions[endpoint] = view_func
def route(self, rule, **options):
"""A decorator that is used to register a view function for a
given URL rule. This does the same thing as :meth:`add_url_rule`
but is intended for decorator usage::
@app.route('/')
def index():
return 'Hello World'
For more information refer to :ref:`url-route-registrations`.
:param rule: the URL rule as string
:param endpoint: the endpoint for the registered URL rule. Flask
itself assumes the name of the view function as
endpoint
:param options: the options to be forwarded to the underlying
:class:`~werkzeug.routing.Rule` object. A change
to Werkzeug is handling of method options. methods
is a list of methods this rule should be limited
to (``GET``, ``POST`` etc.). By default a rule
just listens for ``GET`` (and implicitly ``HEAD``).
Starting with Flask 0.6, ``OPTIONS`` is implicitly
added and handled by the standard request handling.
"""
def decorator(f):
endpoint = options.pop("endpoint", None)
self.add_url_rule(rule, endpoint, f, **options)
return f
return decorator
@setupmethod
def endpoint(self, endpoint):
"""A decorator to register a function as an endpoint.
Example::
@app.endpoint('example.endpoint')
def example():
return "example"
:param endpoint: the name of the endpoint
"""
def decorator(f):
self.view_functions[endpoint] = f
return f
return decorator
@staticmethod
def _get_exc_class_and_code(exc_class_or_code):
"""Get the exception class being handled. For HTTP status codes
or ``HTTPException`` subclasses, return both the exception and
status code.
:param exc_class_or_code: Any exception class, or an HTTP status
code as an integer.
"""
if isinstance(exc_class_or_code, integer_types):
exc_class = default_exceptions[exc_class_or_code]
else:
exc_class = exc_class_or_code
assert issubclass(exc_class, Exception)
if issubclass(exc_class, HTTPException):
return exc_class, exc_class.code
else:
return exc_class, None
@setupmethod
def errorhandler(self, code_or_exception):
"""Register a function to handle errors by code or exception class.
A decorator that is used to register a function given an
error code. Example::
@app.errorhandler(404)
def page_not_found(error):
return 'This page does not exist', 404
You can also register handlers for arbitrary exceptions::
@app.errorhandler(DatabaseError)
def special_exception_handler(error):
return 'Database connection failed', 500
.. versionadded:: 0.7
Use :meth:`register_error_handler` instead of modifying
:attr:`error_handler_spec` directly, for application wide error
handlers.
.. versionadded:: 0.7
One can now additionally also register custom exception types
that do not necessarily have to be a subclass of the
:class:`~werkzeug.exceptions.HTTPException` class.
:param code_or_exception: the code as integer for the handler, or
an arbitrary exception
"""
def decorator(f):
self._register_error_handler(None, code_or_exception, f)
return f
return decorator
@setupmethod
def register_error_handler(self, code_or_exception, f):
"""Alternative error attach function to the :meth:`errorhandler`
decorator that is more straightforward to use for non decorator
usage.
.. versionadded:: 0.7
"""
self._register_error_handler(None, code_or_exception, f)
@setupmethod
def _register_error_handler(self, key, code_or_exception, f):
"""
:type key: None|str
:type code_or_exception: int|T<=Exception
:type f: callable
"""
if isinstance(code_or_exception, HTTPException): # old broken behavior
raise ValueError(
"Tried to register a handler for an exception instance {0!r}."
" Handlers can only be registered for exception classes or"
" HTTP error codes.".format(code_or_exception)
)
try:
exc_class, code = self._get_exc_class_and_code(code_or_exception)
except KeyError:
raise KeyError(
"'{0}' is not a recognized HTTP error code. Use a subclass of"
" HTTPException with that code instead.".format(code_or_exception)
)
handlers = self.error_handler_spec.setdefault(key, {}).setdefault(code, {})
handlers[exc_class] = f
@setupmethod
def template_filter(self, name=None):
"""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):
self.add_template_filter(f, name=name)
return f
return decorator
@setupmethod
def add_template_filter(self, f, name=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=None):
"""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):
self.add_template_test(f, name=name)
return f
return decorator
@setupmethod
def add_template_test(self, f, name=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=None):
"""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):
self.add_template_global(f, name=name)
return f
return decorator
@setupmethod
def add_template_global(self, f, name=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_request(self, f):
"""Registers a function to run before each request.
For example, this can be used to open a database connection, or to load
the logged in user from the session.
The function will be called without any arguments. If it 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.
"""
self.before_request_funcs.setdefault(None, []).append(f)
return f
@setupmethod
def before_first_request(self, f):
"""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.
.. versionadded:: 0.8
"""
self.before_first_request_funcs.append(f)
return f
@setupmethod
def after_request(self, f):
"""Register a function to be run after each request.
Your function must take one parameter, an instance of
:attr:`response_class` and return a new response object or the
same (see :meth:`process_response`).
As of Flask 0.7 this function might not be executed at the end of the
request in case an unhandled exception occurred.
"""
self.after_request_funcs.setdefault(None, []).append(f)
return f
@setupmethod
def teardown_request(self, f):
"""Register a function to be run at the end of each request,
regardless of whether there was an exception or not. These functions
are executed when the request context is popped, even if not an
actual request was performed.
Example::
ctx = app.test_request_context()
ctx.push()
...
ctx.pop()
When ``ctx.pop()`` is executed in the above example, the teardown
functions are called just before the request context moves from the
stack of active contexts. This becomes relevant if you are using
such constructs in tests.
Generally teardown functions must take every necessary step to avoid
that they will fail. If they do execute code that might fail they
will have to surround the execution of these code by try/except
statements and log occurring errors.
When a teardown function was called because of an exception it will
be passed an error object.
The return values of teardown functions are ignored.
.. admonition:: Debug Note
In debug mode Flask will not tear down a request on an exception
immediately. Instead it will keep it alive so that the interactive
debugger can still access it. This behavior can be controlled
by the ``PRESERVE_CONTEXT_ON_EXCEPTION`` configuration variable.
"""
self.teardown_request_funcs.setdefault(None, []).append(f)
return f
@setupmethod
def teardown_appcontext(self, f):
"""Registers a function to be called when the application context
ends. These functions are typically also called when the request
context is popped.
Example::
ctx = app.app_context()
ctx.push()
...
ctx.pop()
When ``ctx.pop()`` is executed in the above example, the teardown
functions are called just before the app context moves from the
stack of active contexts. This becomes relevant if you are using
such constructs in tests.
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.
The return values of teardown functions are ignored.
.. versionadded:: 0.9
"""
self.teardown_appcontext_funcs.append(f)
return f
@setupmethod
def context_processor(self, f):
"""Registers a template context processor function."""
self.template_context_processors[None].append(f)
return f
@setupmethod
def shell_context_processor(self, f):
"""Registers a shell context processor function.
.. versionadded:: 0.11
"""
self.shell_context_processors.append(f)
return f
@setupmethod
def url_value_preprocessor(self, f):
"""Register a URL value preprocessor function for all view
functions in the application. These functions will be called before the
:meth:`before_request` functions.
The function can modify the values captured from the matched url before
they are passed to the view. For example, this can be used to pop a
common language code value and place it in ``g`` rather than pass it to
every view.
The function is passed the endpoint name and values dict. The return
value is ignored.
"""
self.url_value_preprocessors.setdefault(None, []).append(f)
return f
@setupmethod
def url_defaults(self, f):
"""Callback function for URL defaults for all view functions of the
application. It's called with the endpoint and values and should
update the values passed in place.
"""
self.url_default_functions.setdefault(None, []).append(f)
return f
def _find_error_handler(self, e):
"""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))
for name, c in (
(request.blueprint, code),
(None, code),
(request.blueprint, None),
(None, None),
):
handler_map = self.error_handler_spec.setdefault(name, {}).get(c)
if not handler_map:
continue
for cls in exc_class.__mro__:
handler = handler_map.get(cls)
if handler is not None:
return handler
def handle_http_exception(self, e):
"""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
``HTTPExcpetion`` 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 handler(e)
def trap_http_exception(self, e):
"""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):
"""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
"""
exc_type, exc_value, tb = sys.exc_info()
assert exc_value is e
# ensure not to trash sys.exc_info() at that point in case someone
# wants the traceback preserved in handle_http_exception. Of course
# we cannot prevent users from trashing it themselves in a custom
# trap_http_exception method so that's their fault then.
if isinstance(e, BadRequestKeyError):
if self.debug or self.config["TRAP_BAD_REQUEST_ERRORS"]:
e.show_exception = True
# Werkzeug < 0.15 doesn't add the KeyError to the 400
# message, add it in manually.
# TODO: clean up once Werkzeug >= 0.15.5 is required
if e.args[0] not in e.get_description():
e.description = "KeyError: '{}'".format(*e.args)
elif not hasattr(BadRequestKeyError, "show_exception"):
e.args = ()
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:
reraise(exc_type, exc_value, tb)
return handler(e)
def handle_exception(self, e):
"""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``.
.. note::
Prior to Werkzeug 1.0.0, ``InternalServerError`` will not
always have an ``original_exception`` attribute. Use
``getattr(e, "original_exception", None)`` to simulate the
behavior for compatibility.
.. 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_type, exc_value, tb = sys.exc_info()
got_request_exception.send(self, exception=e)
if self.propagate_exceptions:
# if we want to repropagate the exception, we can attempt to
# raise it with the whole traceback in case we can do that
# (the function was actually called from the except part)
# otherwise, we just raise the error again
if exc_value is e:
reraise(exc_type, exc_value, tb)
else:
raise e
self.log_exception((exc_type, exc_value, tb))
server_error = InternalServerError()
# TODO: pass as param when Werkzeug>=1.0.0 is required
# TODO: also remove note about this from docstring and docs
server_error.original_exception = e
handler = self._find_error_handler(server_error)
if handler is not None:
server_error = handler(server_error)
return self.finalize_request(server_error, from_error_handler=True)
def log_exception(self, exc_info):
"""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(
"Exception on %s [%s]" % (request.path, request.method), exc_info=exc_info
)
def raise_routing_exception(self, request):
"""Exceptions that are recording during routing are reraised with
this method. During debug we are not reraising redirect requests
for non ``GET``, ``HEAD``, or ``OPTIONS`` requests and we're raising
a different error instead to help debug situations.
:internal:
"""
if (
not self.debug
or not isinstance(request.routing_exception, RequestRedirect)
or request.method in ("GET", "HEAD", "OPTIONS")
):
raise request.routing_exception
from .debughelpers import FormDataRoutingRedirect
raise FormDataRoutingRedirect(request)
def dispatch_request(self):
"""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_stack.top.request
if req.routing_exception is not None:
self.raise_routing_exception(req)
rule = req.url_rule
# 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
return self.view_functions[rule.endpoint](**req.view_args)
def full_dispatch_request(self):
"""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
"""
self.try_trigger_before_first_request_functions()
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, from_error_handler=False):
"""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 try_trigger_before_first_request_functions(self):
"""Called before each request and will ensure that it triggers
the :attr:`before_first_request_funcs` and only exactly once per
application instance (which means process usually).
:internal:
"""
if self._got_first_request:
return
with self._before_request_lock:
if self._got_first_request:
return
for func in self.before_first_request_funcs:
func()
self._got_first_request = True
def make_default_options_response(self):
"""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_stack.top.url_adapter
if hasattr(adapter, "allowed_methods"):
methods = adapter.allowed_methods()
else:
# fallback for Werkzeug < 0.7
methods = []
try:
adapter.match(method="--")
except MethodNotAllowed as e:
methods = e.valid_methods
except HTTPException:
pass
rv = self.response_class()
rv.allow.update(methods)
return rv
def should_ignore_error(self, error):
"""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 make_response(self, rv):
"""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`` (``unicode`` in Python 2)
A response object is created with the string encoded to UTF-8
as the body.
``bytes`` (``str`` in Python 2)
A response object is created with the bytes as the body.
``dict``
A dictionary that will be jsonify'd before being returned.
``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:: 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
# 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
# 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(
"The view function 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, (text_type, bytes, bytearray)):
# 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)
status = headers = None
elif isinstance(rv, dict):
rv = jsonify(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)
except TypeError as e:
new_error = TypeError(
"{e}\nThe view function did not return a valid"
" response. The return type must be a string, dict, tuple,"
" Response instance, or WSGI callable, but it was a"
" {rv.__class__.__name__}.".format(e=e, rv=rv)
)
reraise(TypeError, new_error, sys.exc_info()[2])
else:
raise TypeError(
"The view function did not return a valid"
" response. The return type must be a string, dict, tuple,"
" Response instance, or WSGI callable, but it was a"
" {rv.__class__.__name__}.".format(rv=rv)
)
# prefer the status if it was provided
if status is not None:
if isinstance(status, (text_type, bytes, bytearray)):
rv.status = status
else:
rv.status_code = status
# extend existing headers with provided headers
if headers:
rv.headers.extend(headers)
return rv
def create_url_adapter(self, request):
"""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.
subdomain = (
(self.url_map.default_subdomain or None)
if not self.subdomain_matching
else 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"],
)
def inject_url_defaults(self, endpoint, values):
"""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
"""
funcs = self.url_default_functions.get(None, ())
if "." in endpoint:
bp = endpoint.rsplit(".", 1)[0]
funcs = chain(funcs, self.url_default_functions.get(bp, ()))
for func in funcs:
func(endpoint, values)
def handle_url_build_error(self, error, endpoint, values):
"""Handle :class:`~werkzeug.routing.BuildError` on :meth:`url_for`.
"""
exc_type, exc_value, tb = sys.exc_info()
for handler in self.url_build_error_handlers:
try:
rv = handler(error, endpoint, values)
if rv is not None:
return rv
except BuildError as e:
# make error available outside except block (py3)
error = e
# At this point we want to reraise the exception. If the error is
# still the same one we can reraise it with the original traceback,
# otherwise we raise it from here.
if error is exc_value:
reraise(exc_type, exc_value, tb)
raise error
def preprocess_request(self):
"""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.
"""
bp = _request_ctx_stack.top.request.blueprint
funcs = self.url_value_preprocessors.get(None, ())
if bp is not None and bp in self.url_value_preprocessors:
funcs = chain(funcs, self.url_value_preprocessors[bp])
for func in funcs:
func(request.endpoint, request.view_args)
funcs = self.before_request_funcs.get(None, ())
if bp is not None and bp in self.before_request_funcs:
funcs = chain(funcs, self.before_request_funcs[bp])
for func in funcs:
rv = func()
if rv is not None:
return rv
def process_response(self, 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_stack.top
bp = ctx.request.blueprint
funcs = ctx._after_request_functions
if bp is not None and bp in self.after_request_funcs:
funcs = chain(funcs, reversed(self.after_request_funcs[bp]))
if None in self.after_request_funcs:
funcs = chain(funcs, reversed(self.after_request_funcs[None]))
for handler in funcs:
response = handler(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=_sentinel):
"""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]
funcs = reversed(self.teardown_request_funcs.get(None, ()))
bp = _request_ctx_stack.top.request.blueprint
if bp is not None and bp in self.teardown_request_funcs:
funcs = chain(funcs, reversed(self.teardown_request_funcs[bp]))
for func in funcs:
func(exc)
request_tearing_down.send(self, exc=exc)
def do_teardown_appcontext(self, exc=_sentinel):
"""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):
func(exc)
appcontext_tearing_down.send(self, exc=exc)
def app_context(self):
"""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):
"""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, **kwargs):
"""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, start_response):
"""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 = 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 self.should_ignore_error(error):
error = None
ctx.auto_pop(error)
def __call__(self, environ, start_response):
"""The WSGI server calls the Flask application object as the
WSGI application. This calls :meth:`wsgi_app` which can be
wrapped to applying middleware."""
return self.wsgi_app(environ, start_response)
def __repr__(self):
return "<%s %r>" % (self.__class__.__name__, self.name)
env/lib/python3.5/site-packages/flask/blueprints.py 0 → 100644
View file @ ff4a13ed
# -*- coding: utf-8 -*-
"""
flask.blueprints
~~~~~~~~~~~~~~~~
Blueprints are the recommended way to implement larger or more
pluggable applications in Flask 0.7 and later.
:copyright: 2010 Pallets
:license: BSD-3-Clause
"""
from functools import update_wrapper
from .helpers import _endpoint_from_view_func
from .helpers import _PackageBoundObject
# a singleton sentinel value for parameter defaults
_sentinel = object()
class BlueprintSetupState(object):
"""Temporary holder object for registering a blueprint with the
application. An instance of this class is created by the
:meth:`~flask.Blueprint.make_setup_state` method and later passed
to all register callback functions.
"""
def __init__(self, blueprint, app, options, first_registration):
#: a reference to the current application
self.app = app
#: a reference to the blueprint that created this setup state.
self.blueprint = blueprint
#: a dictionary with all options that were passed to the
#: :meth:`~flask.Flask.register_blueprint` method.
self.options = options
#: as blueprints can be registered multiple times with the
#: application and not everything wants to be registered
#: multiple times on it, this attribute can be used to figure
#: out if the blueprint was registered in the past already.
self.first_registration = first_registration
subdomain = self.options.get("subdomain")
if subdomain is None:
subdomain = self.blueprint.subdomain
#: The subdomain that the blueprint should be active for, ``None``
#: otherwise.
self.subdomain = subdomain
url_prefix = self.options.get("url_prefix")
if url_prefix is None:
url_prefix = self.blueprint.url_prefix
#: The prefix that should be used for all URLs defined on the
#: blueprint.
self.url_prefix = url_prefix
#: A dictionary with URL defaults that is added to each and every
#: URL that was defined with the blueprint.
self.url_defaults = dict(self.blueprint.url_values_defaults)
self.url_defaults.update(self.options.get("url_defaults", ()))
def add_url_rule(self, rule, endpoint=None, view_func=None, **options):
"""A helper method to register a rule (and optionally a view function)
to the application. The endpoint is automatically prefixed with the
blueprint's name.
"""
if self.url_prefix is not None:
if rule:
rule = "/".join((self.url_prefix.rstrip("/"), rule.lstrip("/")))
else:
rule = self.url_prefix
options.setdefault("subdomain", self.subdomain)
if endpoint is None:
endpoint = _endpoint_from_view_func(view_func)
defaults = self.url_defaults
if "defaults" in options:
defaults = dict(defaults, **options.pop("defaults"))
self.app.add_url_rule(
rule,
"%s.%s" % (self.blueprint.name, endpoint),
view_func,
defaults=defaults,
**options
)
class Blueprint(_PackageBoundObject):
"""Represents a blueprint, a collection of routes and other
app-related functions that can be registered on a real application
later.
A blueprint is an object that allows defining application functions
without requiring an application object ahead of time. It uses the
same decorators as :class:`~flask.Flask`, but defers the need for an
application by recording them for later registration.
Decorating a function with a blueprint creates a deferred function
that is called with :class:`~flask.blueprints.BlueprintSetupState`
when the blueprint is registered on an application.
See :ref:`blueprints` for more information.
.. versionchanged:: 1.1.0
Blueprints have a ``cli`` group to register nested CLI commands.
The ``cli_group`` parameter controls the name of the group under
the ``flask`` command.
.. versionadded:: 0.7
:param name: The name of the blueprint. Will be prepended to each
endpoint name.
:param import_name: The name of the blueprint package, usually
``__name__``. This helps locate the ``root_path`` for the
blueprint.
:param static_folder: A folder with static files that should be
served by the blueprint's static route. The path is relative to
the blueprint's root path. Blueprint static files are disabled
by default.
:param static_url_path: The url to serve static files from.
Defaults to ``static_folder``. If the blueprint does not have
a ``url_prefix``, the app's static route will take precedence,
and the blueprint's static files won't be accessible.
:param template_folder: A folder with templates that should be added
to the app's template search path. The path is relative to the
blueprint's root path. Blueprint templates are disabled by
default. Blueprint templates have a lower precedence than those
in the app's templates folder.
:param url_prefix: A path to prepend to all of the blueprint's URLs,
to make them distinct from the rest of the app's routes.
:param subdomain: A subdomain that blueprint routes will match on by
default.
:param url_defaults: A dict of default values that blueprint routes
will receive by default.
:param root_path: By default, the blueprint will automatically this
based on ``import_name``. In certain situations this automatic
detection can fail, so the path can be specified manually
instead.
"""
warn_on_modifications = False
_got_registered_once = False
#: Blueprint local JSON decoder class to use.
#: Set to ``None`` to use the app's :class:`~flask.app.Flask.json_encoder`.
json_encoder = None
#: Blueprint local JSON decoder class to use.
#: Set to ``None`` to use the app's :class:`~flask.app.Flask.json_decoder`.
json_decoder = None
# 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,
name,
import_name,
static_folder=None,
static_url_path=None,
template_folder=None,
url_prefix=None,
subdomain=None,
url_defaults=None,
root_path=None,
cli_group=_sentinel,
):
_PackageBoundObject.__init__(
self, import_name, template_folder, root_path=root_path
)
self.name = name
self.url_prefix = url_prefix
self.subdomain = subdomain
self.static_folder = static_folder
self.static_url_path = static_url_path
self.deferred_functions = []
if url_defaults is None:
url_defaults = {}
self.url_values_defaults = url_defaults
self.cli_group = cli_group
def record(self, func):
"""Registers a function that is called when the blueprint is
registered on the application. This function is called with the
state as argument as returned by the :meth:`make_setup_state`
method.
"""
if self._got_registered_once and self.warn_on_modifications:
from warnings import warn
warn(
Warning(
"The blueprint was already registered once "
"but is getting modified now. These changes "
"will not show up."
)
)
self.deferred_functions.append(func)
def record_once(self, func):
"""Works like :meth:`record` but wraps the function in another
function that will ensure the function is only called once. If the
blueprint is registered a second time on the application, the
function passed is not called.
"""
def wrapper(state):
if state.first_registration:
func(state)
return self.record(update_wrapper(wrapper, func))
def make_setup_state(self, app, options, first_registration=False):
"""Creates an instance of :meth:`~flask.blueprints.BlueprintSetupState`
object that is later passed to the register callback functions.
Subclasses can override this to return a subclass of the setup state.
"""
return BlueprintSetupState(self, app, options, first_registration)
def register(self, app, options, first_registration=False):
"""Called by :meth:`Flask.register_blueprint` to register all views
and callbacks registered on the blueprint with the application. Creates
a :class:`.BlueprintSetupState` and calls each :meth:`record` callback
with it.
:param app: The application this blueprint is being registered with.
:param options: Keyword arguments forwarded from
:meth:`~Flask.register_blueprint`.
:param first_registration: Whether this is the first time this
blueprint has been registered on the application.
"""
self._got_registered_once = True
state = self.make_setup_state(app, options, first_registration)
if self.has_static_folder:
state.add_url_rule(
self.static_url_path + "/<path:filename>",
view_func=self.send_static_file,
endpoint="static",
)
for deferred in self.deferred_functions:
deferred(state)
cli_resolved_group = options.get("cli_group", self.cli_group)
if not self.cli.commands:
return
if cli_resolved_group is None:
app.cli.commands.update(self.cli.commands)
elif cli_resolved_group is _sentinel:
self.cli.name = self.name
app.cli.add_command(self.cli)
else:
self.cli.name = cli_resolved_group
app.cli.add_command(self.cli)
def route(self, rule, **options):
"""Like :meth:`Flask.route` but for a blueprint. The endpoint for the
:func:`url_for` function is prefixed with the name of the blueprint.
"""
def decorator(f):
endpoint = options.pop("endpoint", f.__name__)
self.add_url_rule(rule, endpoint, f, **options)
return f
return decorator
def add_url_rule(self, rule, endpoint=None, view_func=None, **options):
"""Like :meth:`Flask.add_url_rule` but for a blueprint. The endpoint for
the :func:`url_for` function is prefixed with the name of the blueprint.
"""
if endpoint:
assert "." not in endpoint, "Blueprint endpoints should not contain dots"
if view_func and hasattr(view_func, "__name__"):
assert (
"." not in view_func.__name__
), "Blueprint view function name should not contain dots"
self.record(lambda s: s.add_url_rule(rule, endpoint, view_func, **options))
def endpoint(self, endpoint):
"""Like :meth:`Flask.endpoint` but for a blueprint. This does not
prefix the endpoint with the blueprint name, this has to be done
explicitly by the user of this method. If the endpoint is prefixed
with a `.` it will be registered to the current blueprint, otherwise
it's an application independent endpoint.
"""
def decorator(f):
def register_endpoint(state):
state.app.view_functions[endpoint] = f
self.record_once(register_endpoint)
return f
return decorator
def app_template_filter(self, name=None):
"""Register a custom template filter, available application wide. Like
:meth:`Flask.template_filter` but for a blueprint.
:param name: the optional name of the filter, otherwise the
function name will be used.
"""
def decorator(f):
self.add_app_template_filter(f, name=name)
return f
return decorator
def add_app_template_filter(self, f, name=None):
"""Register a custom template filter, available application wide. Like
:meth:`Flask.add_template_filter` but for a blueprint. Works exactly
like the :meth:`app_template_filter` decorator.
:param name: the optional name of the filter, otherwise the
function name will be used.
"""
def register_template(state):
state.app.jinja_env.filters[name or f.__name__] = f
self.record_once(register_template)
def app_template_test(self, name=None):
"""Register a custom template test, available application wide. Like
:meth:`Flask.template_test` but for a blueprint.
.. versionadded:: 0.10
:param name: the optional name of the test, otherwise the
function name will be used.
"""
def decorator(f):
self.add_app_template_test(f, name=name)
return f
return decorator
def add_app_template_test(self, f, name=None):
"""Register a custom template test, available application wide. Like
:meth:`Flask.add_template_test` but for a blueprint. Works exactly
like the :meth:`app_template_test` decorator.
.. versionadded:: 0.10
:param name: the optional name of the test, otherwise the
function name will be used.
"""
def register_template(state):
state.app.jinja_env.tests[name or f.__name__] = f
self.record_once(register_template)
def app_template_global(self, name=None):
"""Register a custom template global, available application wide. Like
:meth:`Flask.template_global` but for a blueprint.
.. versionadded:: 0.10
:param name: the optional name of the global, otherwise the
function name will be used.
"""
def decorator(f):
self.add_app_template_global(f, name=name)
return f
return decorator
def add_app_template_global(self, f, name=None):
"""Register a custom template global, available application wide. Like
:meth:`Flask.add_template_global` but for a blueprint. Works exactly
like the :meth:`app_template_global` decorator.
.. versionadded:: 0.10
:param name: the optional name of the global, otherwise the
function name will be used.
"""
def register_template(state):
state.app.jinja_env.globals[name or f.__name__] = f
self.record_once(register_template)
def before_request(self, f):
"""Like :meth:`Flask.before_request` but for a blueprint. This function
is only executed before each request that is handled by a function of
that blueprint.
"""
self.record_once(
lambda s: s.app.before_request_funcs.setdefault(self.name, []).append(f)
)
return f
def before_app_request(self, f):
"""Like :meth:`Flask.before_request`. Such a function is executed
before each request, even if outside of a blueprint.
"""
self.record_once(
lambda s: s.app.before_request_funcs.setdefault(None, []).append(f)
)
return f
def before_app_first_request(self, f):
"""Like :meth:`Flask.before_first_request`. Such a function is
executed before the first request to the application.
"""
self.record_once(lambda s: s.app.before_first_request_funcs.append(f))
return f
def after_request(self, f):
"""Like :meth:`Flask.after_request` but for a blueprint. This function
is only executed after each request that is handled by a function of
that blueprint.
"""
self.record_once(
lambda s: s.app.after_request_funcs.setdefault(self.name, []).append(f)
)
return f
def after_app_request(self, f):
"""Like :meth:`Flask.after_request` but for a blueprint. Such a function
is executed after each request, even if outside of the blueprint.
"""
self.record_once(
lambda s: s.app.after_request_funcs.setdefault(None, []).append(f)
)
return f
def teardown_request(self, f):
"""Like :meth:`Flask.teardown_request` but for a blueprint. This
function is only executed when tearing down requests handled by a
function of that blueprint. Teardown request functions are executed
when the request context is popped, even when no actual request was
performed.
"""
self.record_once(
lambda s: s.app.teardown_request_funcs.setdefault(self.name, []).append(f)
)
return f
def teardown_app_request(self, f):
"""Like :meth:`Flask.teardown_request` but for a blueprint. Such a
function is executed when tearing down each request, even if outside of
the blueprint.
"""
self.record_once(
lambda s: s.app.teardown_request_funcs.setdefault(None, []).append(f)
)
return f
def context_processor(self, f):
"""Like :meth:`Flask.context_processor` but for a blueprint. This
function is only executed for requests handled by a blueprint.
"""
self.record_once(
lambda s: s.app.template_context_processors.setdefault(
self.name, []
).append(f)
)
return f
def app_context_processor(self, f):
"""Like :meth:`Flask.context_processor` but for a blueprint. Such a
function is executed each request, even if outside of the blueprint.
"""
self.record_once(
lambda s: s.app.template_context_processors.setdefault(None, []).append(f)
)
return f
def app_errorhandler(self, code):
"""Like :meth:`Flask.errorhandler` but for a blueprint. This
handler is used for all requests, even if outside of the blueprint.
"""
def decorator(f):
self.record_once(lambda s: s.app.errorhandler(code)(f))
return f
return decorator
def url_value_preprocessor(self, f):
"""Registers a function as URL value preprocessor for this
blueprint. It's called before the view functions are called and
can modify the url values provided.
"""
self.record_once(
lambda s: s.app.url_value_preprocessors.setdefault(self.name, []).append(f)
)
return f
def url_defaults(self, f):
"""Callback function for URL defaults for this blueprint. It's called
with the endpoint and values and should update the values passed
in place.
"""
self.record_once(
lambda s: s.app.url_default_functions.setdefault(self.name, []).append(f)
)
return f
def app_url_value_preprocessor(self, f):
"""Same as :meth:`url_value_preprocessor` but application wide.
"""
self.record_once(
lambda s: s.app.url_value_preprocessors.setdefault(None, []).append(f)
)
return f
def app_url_defaults(self, f):
"""Same as :meth:`url_defaults` but application wide.
"""
self.record_once(
lambda s: s.app.url_default_functions.setdefault(None, []).append(f)
)
return f
def errorhandler(self, code_or_exception):
"""Registers an error handler that becomes active for this blueprint
only. Please be aware that routing does not happen local to a
blueprint so an error handler for 404 usually is not handled by
a blueprint unless it is caused inside a view function. Another
special case is the 500 internal server error which is always looked
up from the application.
Otherwise works as the :meth:`~flask.Flask.errorhandler` decorator
of the :class:`~flask.Flask` object.
"""
def decorator(f):
self.record_once(
lambda s: s.app._register_error_handler(self.name, code_or_exception, f)
)
return f
return decorator
def register_error_handler(self, code_or_exception, f):
"""Non-decorator version of the :meth:`errorhandler` error attach
function, akin to the :meth:`~flask.Flask.register_error_handler`
application-wide function of the :class:`~flask.Flask` object but
for error handlers limited to this blueprint.
.. versionadded:: 0.11
"""
self.record_once(
lambda s: s.app._register_error_handler(self.name, code_or_exception, f)
)
env/lib/python3.5/site-packages/flask/cli.py 0 → 100644
View file @ ff4a13ed
# -*- coding: utf-8 -*-
"""
flask.cli
~~~~~~~~~
A simple command line application to run flask apps.
:copyright: 2010 Pallets
:license: BSD-3-Clause
"""
from __future__ import print_function
import ast
import inspect
import os
import platform
import re
import sys
import traceback
from functools import update_wrapper
from operator import attrgetter
from threading import Lock
from threading import Thread
import click
from werkzeug.utils import import_string
from ._compat import getargspec
from ._compat import itervalues
from ._compat import reraise
from ._compat import text_type
from .globals import current_app
from .helpers import get_debug_flag
from .helpers import get_env
from .helpers import get_load_dotenv
try:
import dotenv
except ImportError:
dotenv = None
try:
import ssl
except ImportError:
ssl = None
class NoAppException(click.UsageError):
"""Raised if an application cannot be found or loaded."""
def find_best_app(script_info, module):
"""Given a module instance this tries to find the best possible
application in the module or raises an exception.
"""
from . import Flask
# Search for the most common names first.
for attr_name in ("app", "application"):
app = getattr(module, attr_name, None)
if isinstance(app, Flask):
return app
# Otherwise find the only object that is a Flask instance.
matches = [v for v in itervalues(module.__dict__) if isinstance(v, Flask)]
if len(matches) == 1:
return matches[0]
elif len(matches) > 1:
raise NoAppException(
'Detected multiple Flask applications in module "{module}". Use '
'"FLASK_APP={module}:name" to specify the correct '
"one.".format(module=module.__name__)
)
# Search for app factory functions.
for attr_name in ("create_app", "make_app"):
app_factory = getattr(module, attr_name, None)
if inspect.isfunction(app_factory):
try:
app = call_factory(script_info, app_factory)
if isinstance(app, Flask):
return app
except TypeError:
if not _called_with_wrong_args(app_factory):
raise
raise NoAppException(
'Detected factory "{factory}" in module "{module}", but '
"could not call it without arguments. Use "
"\"FLASK_APP='{module}:{factory}(args)'\" to specify "
"arguments.".format(factory=attr_name, module=module.__name__)
)
raise NoAppException(
'Failed to find Flask application or factory in module "{module}". '
'Use "FLASK_APP={module}:name to specify one.'.format(module=module.__name__)
)
def call_factory(script_info, app_factory, arguments=()):
"""Takes an app factory, a ``script_info` object and optionally a tuple
of arguments. Checks for the existence of a script_info argument and calls
the app_factory depending on that and the arguments provided.
"""
args_spec = getargspec(app_factory)
arg_names = args_spec.args
arg_defaults = args_spec.defaults
if "script_info" in arg_names:
return app_factory(*arguments, script_info=script_info)
elif arguments:
return app_factory(*arguments)
elif not arguments and len(arg_names) == 1 and arg_defaults is None:
return app_factory(script_info)
return app_factory()
def _called_with_wrong_args(factory):
"""Check whether calling a function raised a ``TypeError`` because
the call failed or because something in the factory raised the
error.
:param factory: the factory function that was called
:return: true if the call failed
"""
tb = sys.exc_info()[2]
try:
while tb is not None:
if tb.tb_frame.f_code is factory.__code__:
# in the factory, it was called successfully
return False
tb = tb.tb_next
# didn't reach the factory
return True
finally:
# explicitly delete tb as it is circular referenced
# https://docs.python.org/2/library/sys.html#sys.exc_info
del tb
def find_app_by_string(script_info, module, app_name):
"""Checks if the given string is a variable name or a function. If it is a
function, it checks for specified arguments and whether it takes a
``script_info`` argument and calls the function with the appropriate
arguments.
"""
from . import Flask
match = re.match(r"^ *([^ ()]+) *(?:\((.*?) *,? *\))? *$", app_name)
if not match:
raise NoAppException(
'"{name}" is not a valid variable name or function '
"expression.".format(name=app_name)
)
name, args = match.groups()
try:
attr = getattr(module, name)
except AttributeError as e:
raise NoAppException(e.args[0])
if inspect.isfunction(attr):
if args:
try:
args = ast.literal_eval("({args},)".format(args=args))
except (ValueError, SyntaxError) as e:
raise NoAppException(
"Could not parse the arguments in "
'"{app_name}".'.format(e=e, app_name=app_name)
)
else:
args = ()
try:
app = call_factory(script_info, attr, args)
except TypeError as e:
if not _called_with_wrong_args(attr):
raise
raise NoAppException(
'{e}\nThe factory "{app_name}" in module "{module}" could not '
"be called with the specified arguments.".format(
e=e, app_name=app_name, module=module.__name__
)
)
else:
app = attr
if isinstance(app, Flask):
return app
raise NoAppException(
"A valid Flask application was not obtained from "
'"{module}:{app_name}".'.format(module=module.__name__, app_name=app_name)
)
def prepare_import(path):
"""Given a filename this will try to calculate the python path, add it
to the search path and return the actual module name that is expected.
"""
path = os.path.realpath(path)
fname, ext = os.path.splitext(path)
if ext == ".py":
path = fname
if os.path.basename(path) == "__init__":
path = os.path.dirname(path)
module_name = []
# move up until outside package structure (no __init__.py)
while True:
path, name = os.path.split(path)
module_name.append(name)
if not os.path.exists(os.path.join(path, "__init__.py")):
break
if sys.path[0] != path:
sys.path.insert(0, path)
return ".".join(module_name[::-1])
def locate_app(script_info, module_name, app_name, raise_if_not_found=True):
__traceback_hide__ = True # noqa: F841
try:
__import__(module_name)
except ImportError:
# Reraise the ImportError if it occurred within the imported module.
# Determine this by checking whether the trace has a depth > 1.
if sys.exc_info()[-1].tb_next:
raise NoAppException(
'While importing "{name}", an ImportError was raised:'
"\n\n{tb}".format(name=module_name, tb=traceback.format_exc())
)
elif raise_if_not_found:
raise NoAppException('Could not import "{name}".'.format(name=module_name))
else:
return
module = sys.modules[module_name]
if app_name is None:
return find_best_app(script_info, module)
else:
return find_app_by_string(script_info, module, app_name)
def get_version(ctx, param, value):
if not value or ctx.resilient_parsing:
return
import werkzeug
from . import __version__
message = "Python %(python)s\nFlask %(flask)s\nWerkzeug %(werkzeug)s"
click.echo(
message
% {
"python": platform.python_version(),
"flask": __version__,
"werkzeug": werkzeug.__version__,
},
color=ctx.color,
)
ctx.exit()
version_option = click.Option(
["--version"],
help="Show the flask version",
expose_value=False,
callback=get_version,
is_flag=True,
is_eager=True,
)
class DispatchingApp(object):
"""Special application that dispatches to a Flask application which
is imported by name in a background thread. If an error happens
it is recorded and shown as part of the WSGI handling which in case
of the Werkzeug debugger means that it shows up in the browser.
"""
def __init__(self, loader, use_eager_loading=False):
self.loader = loader
self._app = None
self._lock = Lock()
self._bg_loading_exc_info = None
if use_eager_loading:
self._load_unlocked()
else:
self._load_in_background()
def _load_in_background(self):
def _load_app():
__traceback_hide__ = True # noqa: F841
with self._lock:
try:
self._load_unlocked()
except Exception:
self._bg_loading_exc_info = sys.exc_info()
t = Thread(target=_load_app, args=())
t.start()
def _flush_bg_loading_exception(self):
__traceback_hide__ = True # noqa: F841
exc_info = self._bg_loading_exc_info
if exc_info is not None:
self._bg_loading_exc_info = None
reraise(*exc_info)
def _load_unlocked(self):
__traceback_hide__ = True # noqa: F841
self._app = rv = self.loader()
self._bg_loading_exc_info = None
return rv
def __call__(self, environ, start_response):
__traceback_hide__ = True # noqa: F841
if self._app is not None:
return self._app(environ, start_response)
self._flush_bg_loading_exception()
with self._lock:
if self._app is not None:
rv = self._app
else:
rv = self._load_unlocked()
return rv(environ, start_response)
class ScriptInfo(object):
"""Helper object to deal with Flask applications. This is usually not
necessary to interface with as it's used internally in the dispatching
to click. In future versions of Flask this object will most likely play
a bigger role. Typically it's created automatically by the
:class:`FlaskGroup` but you can also manually create it and pass it
onwards as click object.
"""
def __init__(self, app_import_path=None, create_app=None, set_debug_flag=True):
#: Optionally the import path for the Flask application.
self.app_import_path = app_import_path or os.environ.get("FLASK_APP")
#: Optionally a function that is passed the script info to create
#: the instance of the application.
self.create_app = create_app
#: A dictionary with arbitrary data that can be associated with
#: this script info.
self.data = {}
self.set_debug_flag = set_debug_flag
self._loaded_app = None
def load_app(self):
"""Loads the Flask app (if not yet loaded) and returns it. Calling
this multiple times will just result in the already loaded app to
be returned.
"""
__traceback_hide__ = True # noqa: F841
if self._loaded_app is not None:
return self._loaded_app
app = None
if self.create_app is not None:
app = call_factory(self, self.create_app)
else:
if self.app_import_path:
path, name = (
re.split(r":(?![\\/])", self.app_import_path, 1) + [None]
)[:2]
import_name = prepare_import(path)
app = locate_app(self, import_name, name)
else:
for path in ("wsgi.py", "app.py"):
import_name = prepare_import(path)
app = locate_app(self, import_name, None, raise_if_not_found=False)
if app:
break
if not app:
raise NoAppException(
"Could not locate a Flask application. You did not provide "
'the "FLASK_APP" environment variable, and a "wsgi.py" or '
'"app.py" module was not found in the current directory.'
)
if self.set_debug_flag:
# Update the app's debug flag through the descriptor so that
# other values repopulate as well.
app.debug = get_debug_flag()
self._loaded_app = app
return app
pass_script_info = click.make_pass_decorator(ScriptInfo, ensure=True)
def with_appcontext(f):
"""Wraps a callback so that it's guaranteed to be executed with the
script's application context. If callbacks are registered directly
to the ``app.cli`` object then they are wrapped with this function
by default unless it's disabled.
"""
@click.pass_context
def decorator(__ctx, *args, **kwargs):
with __ctx.ensure_object(ScriptInfo).load_app().app_context():
return __ctx.invoke(f, *args, **kwargs)
return update_wrapper(decorator, f)
class AppGroup(click.Group):
"""This works similar to a regular click :class:`~click.Group` but it
changes the behavior of the :meth:`command` decorator so that it
automatically wraps the functions in :func:`with_appcontext`.
Not to be confused with :class:`FlaskGroup`.
"""
def command(self, *args, **kwargs):
"""This works exactly like the method of the same name on a regular
:class:`click.Group` but it wraps callbacks in :func:`with_appcontext`
unless it's disabled by passing ``with_appcontext=False``.
"""
wrap_for_ctx = kwargs.pop("with_appcontext", True)
def decorator(f):
if wrap_for_ctx:
f = with_appcontext(f)
return click.Group.command(self, *args, **kwargs)(f)
return decorator
def group(self, *args, **kwargs):
"""This works exactly like the method of the same name on a regular
:class:`click.Group` but it defaults the group class to
:class:`AppGroup`.
"""
kwargs.setdefault("cls", AppGroup)
return click.Group.group(self, *args, **kwargs)
class FlaskGroup(AppGroup):
"""Special subclass of the :class:`AppGroup` group that supports
loading more commands from the configured Flask app. Normally a
developer does not have to interface with this class but there are
some very advanced use cases for which it makes sense to create an
instance of this.
For information as of why this is useful see :ref:`custom-scripts`.
:param add_default_commands: if this is True then the default run and
shell commands will be added.
:param add_version_option: adds the ``--version`` option.
:param create_app: an optional callback that is passed the script info and
returns the loaded app.
: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 set_debug_flag: Set the app's debug flag based on the active
environment
.. versionchanged:: 1.0
If installed, python-dotenv will be used to load environment variables
from :file:`.env` and :file:`.flaskenv` files.
"""
def __init__(
self,
add_default_commands=True,
create_app=None,
add_version_option=True,
load_dotenv=True,
set_debug_flag=True,
**extra
):
params = list(extra.pop("params", None) or ())
if add_version_option:
params.append(version_option)
AppGroup.__init__(self, params=params, **extra)
self.create_app = create_app
self.load_dotenv = load_dotenv
self.set_debug_flag = set_debug_flag
if add_default_commands:
self.add_command(run_command)
self.add_command(shell_command)
self.add_command(routes_command)
self._loaded_plugin_commands = False
def _load_plugin_commands(self):
if self._loaded_plugin_commands:
return
try:
import pkg_resources
except ImportError:
self._loaded_plugin_commands = True
return
for ep in pkg_resources.iter_entry_points("flask.commands"):
self.add_command(ep.load(), ep.name)
self._loaded_plugin_commands = True
def get_command(self, ctx, name):
self._load_plugin_commands()
# We load built-in commands first as these should always be the
# same no matter what the app does. If the app does want to
# override this it needs to make a custom instance of this group
# and not attach the default commands.
#
# This also means that the script stays functional in case the
# application completely fails.
rv = AppGroup.get_command(self, ctx, name)
if rv is not None:
return rv
info = ctx.ensure_object(ScriptInfo)
try:
rv = info.load_app().cli.get_command(ctx, name)
if rv is not None:
return rv
except NoAppException:
pass
def list_commands(self, ctx):
self._load_plugin_commands()
# The commands available is the list of both the application (if
# available) plus the builtin commands.
rv = set(click.Group.list_commands(self, ctx))
info = ctx.ensure_object(ScriptInfo)
try:
rv.update(info.load_app().cli.list_commands(ctx))
except Exception:
# Here we intentionally swallow all exceptions as we don't
# want the help page to break if the app does not exist.
# If someone attempts to use the command we try to create
# the app again and this will give us the error.
# However, we will not do so silently because that would confuse
# users.
traceback.print_exc()
return sorted(rv)
def main(self, *args, **kwargs):
# Set a global flag that indicates that we were invoked from the
# command line interface. This is detected by Flask.run to make the
# call into a no-op. This is necessary to avoid ugly errors when the
# script that is loaded here also attempts to start a server.
os.environ["FLASK_RUN_FROM_CLI"] = "true"
if get_load_dotenv(self.load_dotenv):
load_dotenv()
obj = kwargs.get("obj")
if obj is None:
obj = ScriptInfo(
create_app=self.create_app, set_debug_flag=self.set_debug_flag
)
kwargs["obj"] = obj
kwargs.setdefault("auto_envvar_prefix", "FLASK")
return super(FlaskGroup, self).main(*args, **kwargs)
def _path_is_ancestor(path, other):
"""Take ``other`` and remove the length of ``path`` from it. Then join it
to ``path``. If it is the original value, ``path`` is an ancestor of
``other``."""
return os.path.join(path, other[len(path) :].lstrip(os.sep)) == other
def load_dotenv(path=None):
"""Load "dotenv" files in order of precedence to set environment variables.
If an env var is already set it is not overwritten, so earlier files in the
list are preferred over later files.
Changes the current working directory to the location of the first file
found, with the assumption that it is in the top level project directory
and will be where the Python path should import local packages from.
This is a no-op if `python-dotenv`_ is not installed.
.. _python-dotenv: https://github.com/theskumar/python-dotenv#readme
:param path: Load the file at this location instead of searching.
:return: ``True`` if a file was loaded.
.. versionchanged:: 1.1.0
Returns ``False`` when python-dotenv is not installed, or when
the given path isn't a file.
.. versionadded:: 1.0
"""
if dotenv is None:
if path or os.path.isfile(".env") or os.path.isfile(".flaskenv"):
click.secho(
" * Tip: There are .env or .flaskenv files present."
' Do "pip install python-dotenv" to use them.',
fg="yellow",
err=True,
)
return False
# if the given path specifies the actual file then return True,
# else False
if path is not None:
if os.path.isfile(path):
return dotenv.load_dotenv(path)
return False
new_dir = None
for name in (".env", ".flaskenv"):
path = dotenv.find_dotenv(name, usecwd=True)
if not path:
continue
if new_dir is None:
new_dir = os.path.dirname(path)
dotenv.load_dotenv(path)
if new_dir and os.getcwd() != new_dir:
os.chdir(new_dir)
return new_dir is not None # at least one file was located and loaded
def show_server_banner(env, debug, app_import_path, eager_loading):
"""Show extra startup messages the first time the server is run,
ignoring the reloader.
"""
if os.environ.get("WERKZEUG_RUN_MAIN") == "true":
return
if app_import_path is not None:
message = ' * Serving Flask app "{0}"'.format(app_import_path)
if not eager_loading:
message += " (lazy loading)"
click.echo(message)
click.echo(" * Environment: {0}".format(env))
if env == "production":
click.secho(
" WARNING: This is a development server. "
"Do not use it in a production deployment.",
fg="red",
)
click.secho(" Use a production WSGI server instead.", dim=True)
if debug is not None:
click.echo(" * Debug mode: {0}".format("on" if debug else "off"))
class CertParamType(click.ParamType):
"""Click option type for the ``--cert`` option. Allows either an
existing file, the string ``'adhoc'``, or an import for a
:class:`~ssl.SSLContext` object.
"""
name = "path"
def __init__(self):
self.path_type = click.Path(exists=True, dir_okay=False, resolve_path=True)
def convert(self, value, param, ctx):
if ssl is None:
raise click.BadParameter(
'Using "--cert" requires Python to be compiled with SSL support.',
ctx,
param,
)
try:
return self.path_type(value, param, ctx)
except click.BadParameter:
value = click.STRING(value, param, ctx).lower()
if value == "adhoc":
try:
import OpenSSL # noqa: F401
except ImportError:
raise click.BadParameter(
"Using ad-hoc certificates requires pyOpenSSL.", ctx, param
)
return value
obj = import_string(value, silent=True)
if sys.version_info < (2, 7, 9):
if obj:
return obj
else:
if isinstance(obj, ssl.SSLContext):
return obj
raise
def _validate_key(ctx, param, value):
"""The ``--key`` option must be specified when ``--cert`` is a file.
Modifies the ``cert`` param to be a ``(cert, key)`` pair if needed.
"""
cert = ctx.params.get("cert")
is_adhoc = cert == "adhoc"
if sys.version_info < (2, 7, 9):
is_context = cert and not isinstance(cert, (text_type, bytes))
else:
is_context = isinstance(cert, ssl.SSLContext)
if value is not None:
if is_adhoc:
raise click.BadParameter(
'When "--cert" is "adhoc", "--key" is not used.', ctx, param
)
if is_context:
raise click.BadParameter(
'When "--cert" is an SSLContext object, "--key is not used.', ctx, param
)
if not cert:
raise click.BadParameter('"--cert" must also be specified.', ctx, param)
ctx.params["cert"] = cert, value
else:
if cert and not (is_adhoc or is_context):
raise click.BadParameter('Required when using "--cert".', ctx, param)
return value
class SeparatedPathType(click.Path):
"""Click option type that accepts a list of values separated by the
OS's path separator (``:``, ``;`` on Windows). Each value is
validated as a :class:`click.Path` type.
"""
def convert(self, value, param, ctx):
items = self.split_envvar_value(value)
super_convert = super(SeparatedPathType, self).convert
return [super_convert(item, param, ctx) for item in items]
@click.command("run", short_help="Run a development server.")
@click.option("--host", "-h", default="127.0.0.1", help="The interface to bind to.")
@click.option("--port", "-p", default=5000, help="The port to bind to.")
@click.option(
"--cert", type=CertParamType(), help="Specify a certificate file to use HTTPS."
)
@click.option(
"--key",
type=click.Path(exists=True, dir_okay=False, resolve_path=True),
callback=_validate_key,
expose_value=False,
help="The key file to use when specifying a certificate.",
)
@click.option(
"--reload/--no-reload",
default=None,
help="Enable or disable the reloader. By default the reloader "
"is active if debug is enabled.",
)
@click.option(
"--debugger/--no-debugger",
default=None,
help="Enable or disable the debugger. By default the debugger "
"is active if debug is enabled.",
)
@click.option(
"--eager-loading/--lazy-loader",
default=None,
help="Enable or disable eager loading. By default eager "
"loading is enabled if the reloader is disabled.",
)
@click.option(
"--with-threads/--without-threads",
default=True,
help="Enable or disable multithreading.",
)
@click.option(
"--extra-files",
default=None,
type=SeparatedPathType(),
help=(
"Extra files that trigger a reload on change. Multiple paths"
" are separated by '{}'.".format(os.path.pathsep)
),
)
@pass_script_info
def run_command(
info, host, port, reload, debugger, eager_loading, with_threads, cert, extra_files
):
"""Run a local development server.
This server is for development purposes only. It does not provide
the stability, security, or performance of production WSGI servers.
The reloader and debugger are enabled by default if
FLASK_ENV=development or FLASK_DEBUG=1.
"""
debug = get_debug_flag()
if reload is None:
reload = debug
if debugger is None:
debugger = debug
if eager_loading is None:
eager_loading = not reload
show_server_banner(get_env(), debug, info.app_import_path, eager_loading)
app = DispatchingApp(info.load_app, use_eager_loading=eager_loading)
from werkzeug.serving import run_simple
run_simple(
host,
port,
app,
use_reloader=reload,
use_debugger=debugger,
threaded=with_threads,
ssl_context=cert,
extra_files=extra_files,
)
@click.command("shell", short_help="Run a shell in the app context.")
@with_appcontext
def shell_command():
"""Run an interactive Python shell in the context of a given
Flask application. The application will populate the default
namespace of this shell according to it's configuration.
This is useful for executing small snippets of management code
without having to manually configure the application.
"""
import code
from .globals import _app_ctx_stack
app = _app_ctx_stack.top.app
banner = "Python %s on %s\nApp: %s [%s]\nInstance: %s" % (
sys.version,
sys.platform,
app.import_name,
app.env,
app.instance_path,
)
ctx = {}
# Support the regular Python interpreter startup script if someone
# is using it.
startup = os.environ.get("PYTHONSTARTUP")
if startup and os.path.isfile(startup):
with open(startup, "r") as f:
eval(compile(f.read(), startup, "exec"), ctx)
ctx.update(app.make_shell_context())
code.interact(banner=banner, local=ctx)
@click.command("routes", short_help="Show the routes for the app.")
@click.option(
"--sort",
"-s",
type=click.Choice(("endpoint", "methods", "rule", "match")),
default="endpoint",
help=(
'Method to sort routes by. "match" is the order that Flask will match '
"routes when dispatching a request."
),
)
@click.option("--all-methods", is_flag=True, help="Show HEAD and OPTIONS methods.")
@with_appcontext
def routes_command(sort, all_methods):
"""Show all registered routes with endpoints and methods."""
rules = list(current_app.url_map.iter_rules())
if not rules:
click.echo("No routes were registered.")
return
ignored_methods = set(() if all_methods else ("HEAD", "OPTIONS"))
if sort in ("endpoint", "rule"):
rules = sorted(rules, key=attrgetter(sort))
elif sort == "methods":
rules = sorted(rules, key=lambda rule: sorted(rule.methods))
rule_methods = [", ".join(sorted(rule.methods - ignored_methods)) for rule in rules]
headers = ("Endpoint", "Methods", "Rule")
widths = (
max(len(rule.endpoint) for rule in rules),
max(len(methods) for methods in rule_methods),
max(len(rule.rule) for rule in rules),
)
widths = [max(len(h), w) for h, w in zip(headers, widths)]
row = "{{0:<{0}}} {{1:<{1}}} {{2:<{2}}}".format(*widths)
click.echo(row.format(*headers).strip())
click.echo(row.format(*("-" * width for width in widths)))
for rule, methods in zip(rules, rule_methods):
click.echo(row.format(rule.endpoint, methods, rule.rule).rstrip())
cli = FlaskGroup(
help="""\
A general utility script for Flask applications.
Provides commands from Flask, extensions, and the application. Loads the
application defined in the FLASK_APP environment variable, or from a wsgi.py
file. Setting the FLASK_ENV environment variable to 'development' will enable
debug mode.
\b
{prefix}{cmd} FLASK_APP=hello.py
{prefix}{cmd} FLASK_ENV=development
{prefix}flask run
""".format(
cmd="export" if os.name == "posix" else "set",
prefix="$ " if os.name == "posix" else "> ",
)
)
def main(as_module=False):
# TODO omit sys.argv once https://github.com/pallets/click/issues/536 is fixed
cli.main(args=sys.argv[1:], prog_name="python -m flask" if as_module else None)
if __name__ == "__main__":
main(as_module=True)
env/lib/python3.5/site-packages/flask/config.py 0 → 100644
View file @ ff4a13ed
# -*- coding: utf-8 -*-
"""
flask.config
~~~~~~~~~~~~
Implements the configuration related objects.
:copyright: 2010 Pallets
:license: BSD-3-Clause
"""
import errno
import os
import types
from werkzeug.utils import import_string
from . import json
from ._compat import iteritems
from ._compat import string_types
class ConfigAttribute(object):
"""Makes an attribute forward to the config"""
def __init__(self, name, get_converter=None):
self.__name__ = name
self.get_converter = get_converter
def __get__(self, obj, type=None):
if obj is None:
return self
rv = obj.config[self.__name__]
if self.get_converter is not None:
rv = self.get_converter(rv)
return rv
def __set__(self, obj, value):
obj.config[self.__name__] = value
class Config(dict):
"""Works exactly like a dict but provides ways to fill it from files
or special dictionaries. There are two common patterns to populate the
config.
Either you can fill the config from a config file::
app.config.from_pyfile('yourconfig.cfg')
Or alternatively you can define the configuration options in the
module that calls :meth:`from_object` or provide an import path to
a module that should be loaded. It is also possible to tell it to
use the same module and with that provide the configuration values
just before the call::
DEBUG = True
SECRET_KEY = 'development key'
app.config.from_object(__name__)
In both cases (loading from any Python file or loading from modules),
only uppercase keys are added to the config. This makes it possible to use
lowercase values in the config file for temporary values that are not added
to the config or to define the config keys in the same file that implements
the application.
Probably the most interesting way to load configurations is from an
environment variable pointing to a file::
app.config.from_envvar('YOURAPPLICATION_SETTINGS')
In this case before launching the application you have to set this
environment variable to the file you want to use. On Linux and OS X
use the export statement::
export YOURAPPLICATION_SETTINGS='/path/to/config/file'
On windows use `set` instead.
:param root_path: path to which files are read relative from. When the
config object is created by the application, this is
the application's :attr:`~flask.Flask.root_path`.
:param defaults: an optional dictionary of default values
"""
def __init__(self, root_path, defaults=None):
dict.__init__(self, defaults or {})
self.root_path = root_path
def from_envvar(self, variable_name, silent=False):
"""Loads a configuration from an environment variable pointing to
a configuration file. This is basically just a shortcut with nicer
error messages for this line of code::
app.config.from_pyfile(os.environ['YOURAPPLICATION_SETTINGS'])
:param variable_name: name of the environment variable
:param silent: set to ``True`` if you want silent failure for missing
files.
:return: bool. ``True`` if able to load config, ``False`` otherwise.
"""
rv = os.environ.get(variable_name)
if not rv:
if silent:
return False
raise RuntimeError(
"The environment variable %r is not set "
"and as such configuration could not be "
"loaded. Set this variable and make it "
"point to a configuration file" % variable_name
)
return self.from_pyfile(rv, silent=silent)
def from_pyfile(self, filename, silent=False):
"""Updates the values in the config from a Python file. This function
behaves as if the file was imported as module with the
:meth:`from_object` function.
:param filename: the filename of the config. This can either be an
absolute filename or a filename relative to the
root path.
:param silent: set to ``True`` if you want silent failure for missing
files.
.. versionadded:: 0.7
`silent` parameter.
"""
filename = os.path.join(self.root_path, filename)
d = types.ModuleType("config")
d.__file__ = filename
try:
with open(filename, mode="rb") as config_file:
exec(compile(config_file.read(), filename, "exec"), d.__dict__)
except IOError as e:
if silent and e.errno in (errno.ENOENT, errno.EISDIR, errno.ENOTDIR):
return False
e.strerror = "Unable to load configuration file (%s)" % e.strerror
raise
self.from_object(d)
return True
def from_object(self, obj):
"""Updates the values from the given object. An object can be of one
of the following two types:
- a string: in this case the object with that name will be imported
- an actual object reference: that object is used directly
Objects are usually either modules or classes. :meth:`from_object`
loads only the uppercase attributes of the module/class. A ``dict``
object will not work with :meth:`from_object` because the keys of a
``dict`` are not attributes of the ``dict`` class.
Example of module-based configuration::
app.config.from_object('yourapplication.default_config')
from yourapplication import default_config
app.config.from_object(default_config)
Nothing is done to the object before loading. If the object is a
class and has ``@property`` attributes, it needs to be
instantiated before being passed to this method.
You should not use this function to load the actual configuration but
rather configuration defaults. The actual config should be loaded
with :meth:`from_pyfile` and ideally from a location not within the
package because the package might be installed system wide.
See :ref:`config-dev-prod` for an example of class-based configuration
using :meth:`from_object`.
:param obj: an import name or object
"""
if isinstance(obj, string_types):
obj = import_string(obj)
for key in dir(obj):
if key.isupper():
self[key] = getattr(obj, key)
def from_json(self, filename, silent=False):
"""Updates the values in the config from a JSON file. This function
behaves as if the JSON object was a dictionary and passed to the
:meth:`from_mapping` function.
:param filename: the filename of the JSON file. This can either be an
absolute filename or a filename relative to the
root path.
:param silent: set to ``True`` if you want silent failure for missing
files.
.. versionadded:: 0.11
"""
filename = os.path.join(self.root_path, filename)
try:
with open(filename) as json_file:
obj = json.loads(json_file.read())
except IOError as e:
if silent and e.errno in (errno.ENOENT, errno.EISDIR):
return False
e.strerror = "Unable to load configuration file (%s)" % e.strerror
raise
return self.from_mapping(obj)
def from_mapping(self, *mapping, **kwargs):
"""Updates the config like :meth:`update` ignoring items with non-upper
keys.
.. versionadded:: 0.11
"""
mappings = []
if len(mapping) == 1:
if hasattr(mapping[0], "items"):
mappings.append(mapping[0].items())
else:
mappings.append(mapping[0])
elif len(mapping) > 1:
raise TypeError(
"expected at most 1 positional argument, got %d" % len(mapping)
)
mappings.append(kwargs.items())
for mapping in mappings:
for (key, value) in mapping:
if key.isupper():
self[key] = value
return True
def get_namespace(self, namespace, lowercase=True, trim_namespace=True):
"""Returns a dictionary containing a subset of configuration options
that match the specified namespace/prefix. Example usage::
app.config['IMAGE_STORE_TYPE'] = 'fs'
app.config['IMAGE_STORE_PATH'] = '/var/app/images'
app.config['IMAGE_STORE_BASE_URL'] = 'http://img.website.com'
image_store_config = app.config.get_namespace('IMAGE_STORE_')
The resulting dictionary `image_store_config` would look like::
{
'type': 'fs',
'path': '/var/app/images',
'base_url': 'http://img.website.com'
}
This is often useful when configuration options map directly to
keyword arguments in functions or class constructors.
:param namespace: a configuration namespace
:param lowercase: a flag indicating if the keys of the resulting
dictionary should be lowercase
:param trim_namespace: a flag indicating if the keys of the resulting
dictionary should not include the namespace
.. versionadded:: 0.11
"""
rv = {}
for k, v in iteritems(self):
if not k.startswith(namespace):
continue
if trim_namespace:
key = k[len(namespace) :]
else:
key = k
if lowercase:
key = key.lower()
rv[key] = v
return rv
def __repr__(self):
return "<%s %s>" % (self.__class__.__name__, dict.__repr__(self))
env/lib/python3.5/site-packages/flask/ctx.py 0 → 100644
View file @ ff4a13ed
# -*- coding: utf-8 -*-
"""
flask.ctx
~~~~~~~~~
Implements the objects required to keep the context.
:copyright: 2010 Pallets
:license: BSD-3-Clause
"""
import sys
from functools import update_wrapper
from werkzeug.exceptions import HTTPException
from ._compat import BROKEN_PYPY_CTXMGR_EXIT
from ._compat import reraise
from .globals import _app_ctx_stack
from .globals import _request_ctx_stack
from .signals import appcontext_popped
from .signals import appcontext_pushed
# a singleton sentinel value for parameter defaults
_sentinel = object()
class _AppCtxGlobals(object):
"""A plain object. Used as a namespace for storing data during an
application context.
Creating an app context automatically creates this object, which is
made available as the :data:`g` proxy.
.. describe:: 'key' in g
Check whether an attribute is present.
.. versionadded:: 0.10
.. describe:: iter(g)
Return an iterator over the attribute names.
.. versionadded:: 0.10
"""
def get(self, name, default=None):
"""Get an attribute by name, or a default value. Like
:meth:`dict.get`.
:param name: Name of attribute to get.
:param default: Value to return if the attribute is not present.
.. versionadded:: 0.10
"""
return self.__dict__.get(name, default)
def pop(self, name, default=_sentinel):
"""Get and remove an attribute by name. Like :meth:`dict.pop`.
:param name: Name of attribute to pop.
:param default: Value to return if the attribute is not present,
instead of raise a ``KeyError``.
.. versionadded:: 0.11
"""
if default is _sentinel:
return self.__dict__.pop(name)
else:
return self.__dict__.pop(name, default)
def setdefault(self, name, default=None):
"""Get the value of an attribute if it is present, otherwise
set and return a default value. Like :meth:`dict.setdefault`.
:param name: Name of attribute to get.
:param: default: Value to set and return if the attribute is not
present.
.. versionadded:: 0.11
"""
return self.__dict__.setdefault(name, default)
def __contains__(self, item):
return item in self.__dict__
def __iter__(self):
return iter(self.__dict__)
def __repr__(self):
top = _app_ctx_stack.top
if top is not None:
return "<flask.g of %r>" % top.app.name
return object.__repr__(self)
def after_this_request(f):
"""Executes a function after this request. This is useful to modify
response objects. The function is passed the response object and has
to return the same or a new one.
Example::
@app.route('/')
def index():
@after_this_request
def add_header(response):
response.headers['X-Foo'] = 'Parachute'
return response
return 'Hello World!'
This is more useful if a function other than the view function wants to
modify a response. For instance think of a decorator that wants to add
some headers without converting the return value into a response object.
.. versionadded:: 0.9
"""
_request_ctx_stack.top._after_request_functions.append(f)
return f
def copy_current_request_context(f):
"""A helper function that decorates a function to retain the current
request context. This is useful when working with greenlets. The moment
the function is decorated a copy of the request context is created and
then pushed when the function is called. The current session is also
included in the copied request context.
Example::
import gevent
from flask import copy_current_request_context
@app.route('/')
def index():
@copy_current_request_context
def do_some_work():
# do some work here, it can access flask.request or
# flask.session like you would otherwise in the view function.
...
gevent.spawn(do_some_work)
return 'Regular response'
.. versionadded:: 0.10
"""
top = _request_ctx_stack.top
if top is None:
raise RuntimeError(
"This decorator can only be used at local scopes "
"when a request context is on the stack. For instance within "
"view functions."
)
reqctx = top.copy()
def wrapper(*args, **kwargs):
with reqctx:
return f(*args, **kwargs)
return update_wrapper(wrapper, f)
def has_request_context():
"""If you have code that wants to test if a request context is there or
not this function can be used. For instance, you may want to take advantage
of request information if the request object is available, but fail
silently if it is unavailable.
::
class User(db.Model):
def __init__(self, username, remote_addr=None):
self.username = username
if remote_addr is None and has_request_context():
remote_addr = request.remote_addr
self.remote_addr = remote_addr
Alternatively you can also just test any of the context bound objects
(such as :class:`request` or :class:`g`) for truthness::
class User(db.Model):
def __init__(self, username, remote_addr=None):
self.username = username
if remote_addr is None and request:
remote_addr = request.remote_addr
self.remote_addr = remote_addr
.. versionadded:: 0.7
"""
return _request_ctx_stack.top is not None
def has_app_context():
"""Works like :func:`has_request_context` but for the application
context. You can also just do a boolean check on the
:data:`current_app` object instead.
.. versionadded:: 0.9
"""
return _app_ctx_stack.top is not None
class AppContext(object):
"""The application context binds an application object implicitly
to the current thread or greenlet, similar to how the
:class:`RequestContext` binds request information. The application
context is also implicitly created if a request context is created
but the application is not on top of the individual application
context.
"""
def __init__(self, app):
self.app = app
self.url_adapter = app.create_url_adapter(None)
self.g = app.app_ctx_globals_class()
# Like request context, app contexts can be pushed multiple times
# but there a basic "refcount" is enough to track them.
self._refcnt = 0
def push(self):
"""Binds the app context to the current context."""
self._refcnt += 1
if hasattr(sys, "exc_clear"):
sys.exc_clear()
_app_ctx_stack.push(self)
appcontext_pushed.send(self.app)
def pop(self, exc=_sentinel):
"""Pops the app context."""
try:
self._refcnt -= 1
if self._refcnt <= 0:
if exc is _sentinel:
exc = sys.exc_info()[1]
self.app.do_teardown_appcontext(exc)
finally:
rv = _app_ctx_stack.pop()
assert rv is self, "Popped wrong app context. (%r instead of %r)" % (rv, self)
appcontext_popped.send(self.app)
def __enter__(self):
self.push()
return self
def __exit__(self, exc_type, exc_value, tb):
self.pop(exc_value)
if BROKEN_PYPY_CTXMGR_EXIT and exc_type is not None:
reraise(exc_type, exc_value, tb)
class RequestContext(object):
"""The request context contains all request relevant information. It is
created at the beginning of the request and pushed to the
`_request_ctx_stack` and removed at the end of it. It will create the
URL adapter and request object for the WSGI environment provided.
Do not attempt to use this class directly, instead use
:meth:`~flask.Flask.test_request_context` and
:meth:`~flask.Flask.request_context` to create this object.
When the request context is popped, it will evaluate all the
functions registered on the application for teardown execution
(:meth:`~flask.Flask.teardown_request`).
The request context is automatically popped at the end of the request
for you. In debug mode the request context is kept around if
exceptions happen so that interactive debuggers have a chance to
introspect the data. With 0.4 this can also be forced for requests
that did not fail and outside of ``DEBUG`` mode. By setting
``'flask._preserve_context'`` to ``True`` on the WSGI environment the
context will not pop itself at the end of the request. This is used by
the :meth:`~flask.Flask.test_client` for example to implement the
deferred cleanup functionality.
You might find this helpful for unittests where you need the
information from the context local around for a little longer. Make
sure to properly :meth:`~werkzeug.LocalStack.pop` the stack yourself in
that situation, otherwise your unittests will leak memory.
"""
def __init__(self, app, environ, request=None, session=None):
self.app = app
if request is None:
request = app.request_class(environ)
self.request = request
self.url_adapter = None
try:
self.url_adapter = app.create_url_adapter(self.request)
except HTTPException as e:
self.request.routing_exception = e
self.flashes = None
self.session = session
# Request contexts can be pushed multiple times and interleaved with
# other request contexts. Now only if the last level is popped we
# get rid of them. Additionally if an application context is missing
# one is created implicitly so for each level we add this information
self._implicit_app_ctx_stack = []
# indicator if the context was preserved. Next time another context
# is pushed the preserved context is popped.
self.preserved = False
# remembers the exception for pop if there is one in case the context
# preservation kicks in.
self._preserved_exc = None
# Functions that should be executed after the request on the response
# object. These will be called before the regular "after_request"
# functions.
self._after_request_functions = []
@property
def g(self):
return _app_ctx_stack.top.g
@g.setter
def g(self, value):
_app_ctx_stack.top.g = value
def copy(self):
"""Creates a copy of this request context with the same request object.
This can be used to move a request context to a different greenlet.
Because the actual request object is the same this cannot be used to
move a request context to a different thread unless access to the
request object is locked.
.. versionadded:: 0.10
.. versionchanged:: 1.1
The current session object is used instead of reloading the original
data. This prevents `flask.session` pointing to an out-of-date object.
"""
return self.__class__(
self.app,
environ=self.request.environ,
request=self.request,
session=self.session,
)
def match_request(self):
"""Can be overridden by a subclass to hook into the matching
of the request.
"""
try:
result = self.url_adapter.match(return_rule=True)
self.request.url_rule, self.request.view_args = result
except HTTPException as e:
self.request.routing_exception = e
def push(self):
"""Binds the request context to the current context."""
# If an exception occurs in debug mode or if context preservation is
# activated under exception situations exactly one context stays
# on the stack. The rationale is that you want to access that
# information under debug situations. However if someone forgets to
# pop that context again we want to make sure that on the next push
# it's invalidated, otherwise we run at risk that something leaks
# memory. This is usually only a problem in test suite since this
# functionality is not active in production environments.
top = _request_ctx_stack.top
if top is not None and top.preserved:
top.pop(top._preserved_exc)
# Before we push the request context we have to ensure that there
# is an application context.
app_ctx = _app_ctx_stack.top
if app_ctx is None or app_ctx.app != self.app:
app_ctx = self.app.app_context()
app_ctx.push()
self._implicit_app_ctx_stack.append(app_ctx)
else:
self._implicit_app_ctx_stack.append(None)
if hasattr(sys, "exc_clear"):
sys.exc_clear()
_request_ctx_stack.push(self)
# Open the session at the moment that the request context is available.
# This allows a custom open_session method to use the request context.
# Only open a new session if this is the first time the request was
# pushed, otherwise stream_with_context loses the session.
if self.session is None:
session_interface = self.app.session_interface
self.session = session_interface.open_session(self.app, self.request)
if self.session is None:
self.session = session_interface.make_null_session(self.app)
if self.url_adapter is not None:
self.match_request()
def pop(self, exc=_sentinel):
"""Pops the request context and unbinds it by doing that. This will
also trigger the execution of functions registered by the
:meth:`~flask.Flask.teardown_request` decorator.
.. versionchanged:: 0.9
Added the `exc` argument.
"""
app_ctx = self._implicit_app_ctx_stack.pop()
try:
clear_request = False
if not self._implicit_app_ctx_stack:
self.preserved = False
self._preserved_exc = None
if exc is _sentinel:
exc = sys.exc_info()[1]
self.app.do_teardown_request(exc)
# If this interpreter supports clearing the exception information
# we do that now. This will only go into effect on Python 2.x,
# on 3.x it disappears automatically at the end of the exception
# stack.
if hasattr(sys, "exc_clear"):
sys.exc_clear()
request_close = getattr(self.request, "close", None)
if request_close is not None:
request_close()
clear_request = True
finally:
rv = _request_ctx_stack.pop()
# get rid of circular dependencies at the end of the request
# so that we don't require the GC to be active.
if clear_request:
rv.request.environ["werkzeug.request"] = None
# Get rid of the app as well if necessary.
if app_ctx is not None:
app_ctx.pop(exc)
assert rv is self, "Popped wrong request context. (%r instead of %r)" % (
rv,
self,
)
def auto_pop(self, exc):
if self.request.environ.get("flask._preserve_context") or (
exc is not None and self.app.preserve_context_on_exception
):
self.preserved = True
self._preserved_exc = exc
else:
self.pop(exc)
def __enter__(self):
self.push()
return self
def __exit__(self, exc_type, exc_value, tb):
# do not pop the request stack if we are in debug mode and an
# exception happened. This will allow the debugger to still
# access the request object in the interactive shell. Furthermore
# the context can be force kept alive for the test client.
# See flask.testing for how this works.
self.auto_pop(exc_value)
if BROKEN_PYPY_CTXMGR_EXIT and exc_type is not None:
reraise(exc_type, exc_value, tb)
def __repr__(self):
return "<%s '%s' [%s] of %s>" % (
self.__class__.__name__,
self.request.url,
self.request.method,
self.app.name,
)
env/lib/python3.5/site-packages/flask/debughelpers.py 0 → 100644
View file @ ff4a13ed
# -*- coding: utf-8 -*-
"""
flask.debughelpers
~~~~~~~~~~~~~~~~~~
Various helpers to make the development experience better.
:copyright: 2010 Pallets
:license: BSD-3-Clause
"""
import os
from warnings import warn
from ._compat import implements_to_string
from ._compat import text_type
from .app import Flask
from .blueprints import Blueprint
from .globals import _request_ctx_stack
class UnexpectedUnicodeError(AssertionError, UnicodeError):
"""Raised in places where we want some better error reporting for
unexpected unicode or binary data.
"""
@implements_to_string
class DebugFilesKeyError(KeyError, AssertionError):
"""Raised from request.files during debugging. The idea is that it can
provide a better error message than just a generic KeyError/BadRequest.
"""
def __init__(self, request, key):
form_matches = request.form.getlist(key)
buf = [
'You tried to access the file "%s" in the request.files '
"dictionary but it does not exist. The mimetype for the request "
'is "%s" instead of "multipart/form-data" which means that no '
"file contents were transmitted. To fix this error you should "
'provide enctype="multipart/form-data" in your form.'
% (key, request.mimetype)
]
if form_matches:
buf.append(
"\n\nThe browser instead transmitted some file names. "
"This was submitted: %s" % ", ".join('"%s"' % x for x in form_matches)
)
self.msg = "".join(buf)
def __str__(self):
return self.msg
class FormDataRoutingRedirect(AssertionError):
"""This exception is raised by Flask in debug mode if it detects a
redirect caused by the routing system when the request method is not
GET, HEAD or OPTIONS. Reasoning: form data will be dropped.
"""
def __init__(self, request):
exc = request.routing_exception
buf = [
"A request was sent to this URL (%s) but a redirect was "
'issued automatically by the routing system to "%s".'
% (request.url, exc.new_url)
]
# In case just a slash was appended we can be extra helpful
if request.base_url + "/" == exc.new_url.split("?")[0]:
buf.append(
" The URL was defined with a trailing slash so "
"Flask will automatically redirect to the URL "
"with the trailing slash if it was accessed "
"without one."
)
buf.append(
" Make sure to directly send your %s-request to this URL "
"since we can't make browsers or HTTP clients redirect "
"with form data reliably or without user interaction." % request.method
)
buf.append("\n\nNote: this exception is only raised in debug mode")
AssertionError.__init__(self, "".join(buf).encode("utf-8"))
def attach_enctype_error_multidict(request):
"""Since Flask 0.8 we're monkeypatching the files object in case a
request is detected that does not use multipart form data but the files
object is accessed.
"""
oldcls = request.files.__class__
class newcls(oldcls):
def __getitem__(self, key):
try:
return oldcls.__getitem__(self, key)
except KeyError:
if key not in request.form:
raise
raise DebugFilesKeyError(request, key)
newcls.__name__ = oldcls.__name__
newcls.__module__ = oldcls.__module__
request.files.__class__ = newcls
def _dump_loader_info(loader):
yield "class: %s.%s" % (type(loader).__module__, type(loader).__name__)
for key, value in sorted(loader.__dict__.items()):
if key.startswith("_"):
continue
if isinstance(value, (tuple, list)):
if not all(isinstance(x, (str, text_type)) for x in value):
continue
yield "%s:" % key
for item in value:
yield " - %s" % item
continue
elif not isinstance(value, (str, text_type, int, float, bool)):
continue
yield "%s: %r" % (key, value)
def explain_template_loading_attempts(app, template, attempts):
"""This should help developers understand what failed"""
info = ['Locating template "%s":' % template]
total_found = 0
blueprint = None
reqctx = _request_ctx_stack.top
if reqctx is not None and reqctx.request.blueprint is not None:
blueprint = reqctx.request.blueprint
for idx, (loader, srcobj, triple) in enumerate(attempts):
if isinstance(srcobj, Flask):
src_info = 'application "%s"' % srcobj.import_name
elif isinstance(srcobj, Blueprint):
src_info = 'blueprint "%s" (%s)' % (srcobj.name, srcobj.import_name)
else:
src_info = repr(srcobj)
info.append("% 5d: trying loader of %s" % (idx + 1, src_info))
for line in _dump_loader_info(loader):
info.append(" %s" % line)
if triple is None:
detail = "no match"
else:
detail = "found (%r)" % (triple[1] or "<string>")
total_found += 1
info.append(" -> %s" % detail)
seems_fishy = False
if total_found == 0:
info.append("Error: the template could not be found.")
seems_fishy = True
elif total_found > 1:
info.append("Warning: multiple loaders returned a match for the template.")
seems_fishy = True
if blueprint is not None and seems_fishy:
info.append(
" The template was looked up from an endpoint that "
'belongs to the blueprint "%s".' % blueprint
)
info.append(" Maybe you did not place a template in the right folder?")
info.append(" See http://flask.pocoo.org/docs/blueprints/#templates")
app.logger.info("\n".join(info))
def explain_ignored_app_run():
if os.environ.get("WERKZEUG_RUN_MAIN") != "true":
warn(
Warning(
"Silently ignoring app.run() because the "
"application is run from the flask command line "
"executable. Consider putting app.run() behind an "
'if __name__ == "__main__" guard to silence this '
"warning."
),
stacklevel=3,
)
env/lib/python3.5/site-packages/flask/globals.py 0 → 100644
View file @ ff4a13ed
# -*- coding: utf-8 -*-
"""
flask.globals
~~~~~~~~~~~~~
Defines all the global objects that are proxies to the current
active context.
:copyright: 2010 Pallets
:license: BSD-3-Clause
"""
from functools import partial
from werkzeug.local import LocalProxy
from werkzeug.local import LocalStack
_request_ctx_err_msg = """\
Working outside of request context.
This typically means that you attempted to use functionality that needed
an active HTTP request. Consult the documentation on testing for
information about how to avoid this problem.\
"""
_app_ctx_err_msg = """\
Working outside of application context.
This typically means that you attempted to use functionality that needed
to interface with the current application object in some way. To solve
this, set up an application context with app.app_context(). See the
documentation for more information.\
"""
def _lookup_req_object(name):
top = _request_ctx_stack.top
if top is None:
raise RuntimeError(_request_ctx_err_msg)
return getattr(top, name)
def _lookup_app_object(name):
top = _app_ctx_stack.top
if top is None:
raise RuntimeError(_app_ctx_err_msg)
return getattr(top, name)
def _find_app():
top = _app_ctx_stack.top
if top is None:
raise RuntimeError(_app_ctx_err_msg)
return top.app
# context locals
_request_ctx_stack = LocalStack()
_app_ctx_stack = LocalStack()
current_app = LocalProxy(_find_app)
request = LocalProxy(partial(_lookup_req_object, "request"))
session = LocalProxy(partial(_lookup_req_object, "session"))
g = LocalProxy(partial(_lookup_app_object, "g"))
env/lib/python3.5/site-packages/flask/helpers.py 0 → 100644
View file @ ff4a13ed
# -*- coding: utf-8 -*-
"""
flask.helpers
~~~~~~~~~~~~~
Implements various helpers.
:copyright: 2010 Pallets
:license: BSD-3-Clause
"""
import io
import mimetypes
import os
import pkgutil
import posixpath
import socket
import sys
import unicodedata
from functools import update_wrapper
from threading import RLock
from time import time
from zlib import adler32
from jinja2 import FileSystemLoader
from werkzeug.datastructures import Headers
from werkzeug.exceptions import BadRequest
from werkzeug.exceptions import NotFound
from werkzeug.exceptions import RequestedRangeNotSatisfiable
from werkzeug.routing import BuildError
from werkzeug.urls import url_quote
from werkzeug.wsgi import wrap_file
from ._compat import fspath
from ._compat import PY2
from ._compat import string_types
from ._compat import text_type
from .globals import _app_ctx_stack
from .globals import _request_ctx_stack
from .globals import current_app
from .globals import request
from .globals import session
from .signals import message_flashed
# sentinel
_missing = object()
# what separators does this operating system provide that are not a slash?
# this is used by the send_from_directory function to ensure that nobody is
# able to access files from outside the filesystem.
_os_alt_seps = list(
sep for sep in [os.path.sep, os.path.altsep] if sep not in (None, "/")
)
def get_env():
"""Get the environment the app is running in, indicated by the
:envvar:`FLASK_ENV` environment variable. The default is
``'production'``.
"""
return os.environ.get("FLASK_ENV") or "production"
def get_debug_flag():
"""Get whether debug mode should be enabled for the app, indicated
by the :envvar:`FLASK_DEBUG` environment variable. The default is
``True`` if :func:`.get_env` returns ``'development'``, or ``False``
otherwise.
"""
val = os.environ.get("FLASK_DEBUG")
if not val:
return get_env() == "development"
return val.lower() not in ("0", "false", "no")
def get_load_dotenv(default=True):
"""Get whether the user has disabled loading dotenv files by setting
:envvar:`FLASK_SKIP_DOTENV`. The default is ``True``, load the
files.
:param default: What to return if the env var isn't set.
"""
val = os.environ.get("FLASK_SKIP_DOTENV")
if not val:
return default
return val.lower() in ("0", "false", "no")
def _endpoint_from_view_func(view_func):
"""Internal helper that returns the default endpoint for a given
function. This always is the function name.
"""
assert view_func is not None, "expected view func if endpoint is not provided."
return view_func.__name__
def stream_with_context(generator_or_function):
"""Request contexts disappear when the response is started on the server.
This is done for efficiency reasons and to make it less likely to encounter
memory leaks with badly written WSGI middlewares. The downside is that if
you are using streamed responses, the generator cannot access request bound
information any more.
This function however can help you keep the context around for longer::
from flask import stream_with_context, request, Response
@app.route('/stream')
def streamed_response():
@stream_with_context
def generate():
yield 'Hello '
yield request.args['name']
yield '!'
return Response(generate())
Alternatively it can also be used around a specific generator::
from flask import stream_with_context, request, Response
@app.route('/stream')
def streamed_response():
def generate():
yield 'Hello '
yield request.args['name']
yield '!'
return Response(stream_with_context(generate()))
.. versionadded:: 0.9
"""
try:
gen = iter(generator_or_function)
except TypeError:
def decorator(*args, **kwargs):
gen = generator_or_function(*args, **kwargs)
return stream_with_context(gen)
return update_wrapper(decorator, generator_or_function)
def generator():
ctx = _request_ctx_stack.top
if ctx is None:
raise RuntimeError(
"Attempted to stream with context but "
"there was no context in the first place to keep around."
)
with ctx:
# Dummy sentinel. Has to be inside the context block or we're
# not actually keeping the context around.
yield None
# The try/finally is here so that if someone passes a WSGI level
# iterator in we're still running the cleanup logic. Generators
# don't need that because they are closed on their destruction
# automatically.
try:
for item in gen:
yield item
finally:
if hasattr(gen, "close"):
gen.close()
# The trick is to start the generator. Then the code execution runs until
# the first dummy None is yielded at which point the context was already
# pushed. This item is discarded. Then when the iteration continues the
# real generator is executed.
wrapped_g = generator()
next(wrapped_g)
return wrapped_g
def make_response(*args):
"""Sometimes it is necessary to set additional headers in a view. Because
views do not have to return response objects but can return a value that
is converted into a response object by Flask itself, it becomes tricky to
add headers to it. This function can be called instead of using a return
and you will get a response object which you can use to attach headers.
If view looked like this and you want to add a new header::
def index():
return render_template('index.html', foo=42)
You can now do something like this::
def index():
response = make_response(render_template('index.html', foo=42))
response.headers['X-Parachutes'] = 'parachutes are cool'
return response
This function accepts the very same arguments you can return from a
view function. This for example creates a response with a 404 error
code::
response = make_response(render_template('not_found.html'), 404)
The other use case of this function is to force the return value of a
view function into a response which is helpful with view
decorators::
response = make_response(view_function())
response.headers['X-Parachutes'] = 'parachutes are cool'
Internally this function does the following things:
- if no arguments are passed, it creates a new response argument
- if one argument is passed, :meth:`flask.Flask.make_response`
is invoked with it.
- if more than one argument is passed, the arguments are passed
to the :meth:`flask.Flask.make_response` function as tuple.
.. versionadded:: 0.6
"""
if not args:
return current_app.response_class()
if len(args) == 1:
args = args[0]
return current_app.make_response(args)
def url_for(endpoint, **values):
"""Generates a URL to the given endpoint with the method provided.
Variable arguments that are unknown to the target endpoint are appended
to the generated URL as query arguments. If the value of a query argument
is ``None``, the whole pair is skipped. In case blueprints are active
you can shortcut references to the same blueprint by prefixing the
local endpoint with a dot (``.``).
This will reference the index function local to the current blueprint::
url_for('.index')
For more information, head over to the :ref:`Quickstart <url-building>`.
Configuration values ``APPLICATION_ROOT`` and ``SERVER_NAME`` are only used when
generating URLs outside of a request context.
To integrate applications, :class:`Flask` has a hook to intercept URL build
errors through :attr:`Flask.url_build_error_handlers`. The `url_for`
function results in a :exc:`~werkzeug.routing.BuildError` when the current
app does not have a URL for the given endpoint and values. When it does, the
:data:`~flask.current_app` calls its :attr:`~Flask.url_build_error_handlers` if
it is not ``None``, which can return a string to use as the result of
`url_for` (instead of `url_for`'s default to raise the
:exc:`~werkzeug.routing.BuildError` exception) or re-raise the exception.
An example::
def external_url_handler(error, endpoint, values):
"Looks up an external URL when `url_for` cannot build a URL."
# This is an example of hooking the build_error_handler.
# Here, lookup_url is some utility function you've built
# which looks up the endpoint in some external URL registry.
url = lookup_url(endpoint, **values)
if url is None:
# External lookup did not have a URL.
# Re-raise the BuildError, in context of original traceback.
exc_type, exc_value, tb = sys.exc_info()
if exc_value is error:
raise exc_type, exc_value, tb
else:
raise error
# url_for will use this result, instead of raising BuildError.
return url
app.url_build_error_handlers.append(external_url_handler)
Here, `error` is the instance of :exc:`~werkzeug.routing.BuildError`, and
`endpoint` and `values` are the arguments passed into `url_for`. Note
that this is for building URLs outside the current application, and not for
handling 404 NotFound errors.
.. versionadded:: 0.10
The `_scheme` parameter was added.
.. versionadded:: 0.9
The `_anchor` and `_method` parameters were added.
.. versionadded:: 0.9
Calls :meth:`Flask.handle_build_error` on
:exc:`~werkzeug.routing.BuildError`.
:param endpoint: the endpoint of the URL (name of the function)
:param values: the variable arguments of the URL rule
:param _external: if set to ``True``, an absolute URL is generated. Server
address can be changed via ``SERVER_NAME`` configuration variable which
falls back to the `Host` header, then to the IP and port of the request.
:param _scheme: a string specifying the desired URL scheme. The `_external`
parameter must be set to ``True`` or a :exc:`ValueError` is raised. The default
behavior uses the same scheme as the current request, or
``PREFERRED_URL_SCHEME`` from the :ref:`app configuration <config>` if no
request context is available. As of Werkzeug 0.10, this also can be set
to an empty string to build protocol-relative URLs.
:param _anchor: if provided this is added as anchor to the URL.
:param _method: if provided this explicitly specifies an HTTP method.
"""
appctx = _app_ctx_stack.top
reqctx = _request_ctx_stack.top
if appctx is None:
raise RuntimeError(
"Attempted to generate a URL without the application context being"
" pushed. This has to be executed when application context is"
" available."
)
# If request specific information is available we have some extra
# features that support "relative" URLs.
if reqctx is not None:
url_adapter = reqctx.url_adapter
blueprint_name = request.blueprint
if endpoint[:1] == ".":
if blueprint_name is not None:
endpoint = blueprint_name + endpoint
else:
endpoint = endpoint[1:]
external = values.pop("_external", False)
# Otherwise go with the url adapter from the appctx and make
# the URLs external by default.
else:
url_adapter = appctx.url_adapter
if url_adapter is None:
raise RuntimeError(
"Application was not able to create a URL adapter for request"
" independent URL generation. You might be able to fix this by"
" setting the SERVER_NAME config variable."
)
external = values.pop("_external", True)
anchor = values.pop("_anchor", None)
method = values.pop("_method", None)
scheme = values.pop("_scheme", None)
appctx.app.inject_url_defaults(endpoint, values)
# This is not the best way to deal with this but currently the
# underlying Werkzeug router does not support overriding the scheme on
# a per build call basis.
old_scheme = None
if scheme is not None:
if not external:
raise ValueError("When specifying _scheme, _external must be True")
old_scheme = url_adapter.url_scheme
url_adapter.url_scheme = scheme
try:
try:
rv = url_adapter.build(
endpoint, values, method=method, force_external=external
)
finally:
if old_scheme is not None:
url_adapter.url_scheme = old_scheme
except BuildError as error:
# We need to inject the values again so that the app callback can
# deal with that sort of stuff.
values["_external"] = external
values["_anchor"] = anchor
values["_method"] = method
values["_scheme"] = scheme
return appctx.app.handle_url_build_error(error, endpoint, values)
if anchor is not None:
rv += "#" + url_quote(anchor)
return rv
def get_template_attribute(template_name, attribute):
"""Loads a macro (or variable) a template exports. This can be used to
invoke a macro from within Python code. If you for example have a
template named :file:`_cider.html` with the following contents:
.. sourcecode:: html+jinja
{% macro hello(name) %}Hello {{ name }}!{% endmacro %}
You can access this from Python code like this::
hello = get_template_attribute('_cider.html', 'hello')
return hello('World')
.. versionadded:: 0.2
:param template_name: the name of the template
:param attribute: the name of the variable of macro to access
"""
return getattr(current_app.jinja_env.get_template(template_name).module, attribute)
def flash(message, category="message"):
"""Flashes a message to the next request. In order to remove the
flashed message from the session and to display it to the user,
the template has to call :func:`get_flashed_messages`.
.. versionchanged:: 0.3
`category` parameter added.
:param message: the message to be flashed.
:param category: the category for the message. The following values
are recommended: ``'message'`` for any kind of message,
``'error'`` for errors, ``'info'`` for information
messages and ``'warning'`` for warnings. However any
kind of string can be used as category.
"""
# Original implementation:
#
# session.setdefault('_flashes', []).append((category, message))
#
# This assumed that changes made to mutable structures in the session are
# always in sync with the session object, which is not true for session
# implementations that use external storage for keeping their keys/values.
flashes = session.get("_flashes", [])
flashes.append((category, message))
session["_flashes"] = flashes
message_flashed.send(
current_app._get_current_object(), message=message, category=category
)
def get_flashed_messages(with_categories=False, category_filter=()):
"""Pulls all flashed messages from the session and returns them.
Further calls in the same request to the function will return
the same messages. By default just the messages are returned,
but when `with_categories` is set to ``True``, the return value will
be a list of tuples in the form ``(category, message)`` instead.
Filter the flashed messages to one or more categories by providing those
categories in `category_filter`. This allows rendering categories in
separate html blocks. The `with_categories` and `category_filter`
arguments are distinct:
* `with_categories` controls whether categories are returned with message
text (``True`` gives a tuple, where ``False`` gives just the message text).
* `category_filter` filters the messages down to only those matching the
provided categories.
See :ref:`message-flashing-pattern` for examples.
.. versionchanged:: 0.3
`with_categories` parameter added.
.. versionchanged:: 0.9
`category_filter` parameter added.
:param with_categories: set to ``True`` to also receive categories.
:param category_filter: whitelist of categories to limit return values
"""
flashes = _request_ctx_stack.top.flashes
if flashes is None:
_request_ctx_stack.top.flashes = flashes = (
session.pop("_flashes") if "_flashes" in session else []
)
if category_filter:
flashes = list(filter(lambda f: f[0] in category_filter, flashes))
if not with_categories:
return [x[1] for x in flashes]
return flashes
def send_file(
filename_or_fp,
mimetype=None,
as_attachment=False,
attachment_filename=None,
add_etags=True,
cache_timeout=None,
conditional=False,
last_modified=None,
):
"""Sends the contents of a file to the client. This will use the
most efficient method available and configured. By default it will
try to use the WSGI server's file_wrapper support. Alternatively
you can set the application's :attr:`~Flask.use_x_sendfile` attribute
to ``True`` to directly emit an ``X-Sendfile`` header. This however
requires support of the underlying webserver for ``X-Sendfile``.
By default it will try to guess the mimetype for you, but you can
also explicitly provide one. For extra security you probably want
to send certain files as attachment (HTML for instance). The mimetype
guessing requires a `filename` or an `attachment_filename` to be
provided.
ETags will also be attached automatically if a `filename` is provided. You
can turn this off by setting `add_etags=False`.
If `conditional=True` and `filename` is provided, this method will try to
upgrade the response stream to support range requests. This will allow
the request to be answered with partial content response.
Please never pass filenames to this function from user sources;
you should use :func:`send_from_directory` instead.
.. versionadded:: 0.2
.. versionadded:: 0.5
The `add_etags`, `cache_timeout` and `conditional` parameters were
added. The default behavior is now to attach etags.
.. versionchanged:: 0.7
mimetype guessing and etag support for file objects was
deprecated because it was unreliable. Pass a filename if you are
able to, otherwise attach an etag yourself. This functionality
will be removed in Flask 1.0
.. versionchanged:: 0.9
cache_timeout pulls its default from application config, when None.
.. versionchanged:: 0.12
The filename is no longer automatically inferred from file objects. If
you want to use automatic mimetype and etag support, pass a filepath via
`filename_or_fp` or `attachment_filename`.
.. versionchanged:: 0.12
The `attachment_filename` is preferred over `filename` for MIME-type
detection.
.. versionchanged:: 1.0
UTF-8 filenames, as specified in `RFC 2231`_, are supported.
.. _RFC 2231: https://tools.ietf.org/html/rfc2231#section-4
.. versionchanged:: 1.0.3
Filenames are encoded with ASCII instead of Latin-1 for broader
compatibility with WSGI servers.
.. versionchanged:: 1.1
Filename may be a :class:`~os.PathLike` object.
.. versionadded:: 1.1
Partial content supports :class:`~io.BytesIO`.
:param filename_or_fp: the filename of the file to send.
This is relative to the :attr:`~Flask.root_path`
if a relative path is specified.
Alternatively a file object might be provided in
which case ``X-Sendfile`` might not work and fall
back to the traditional method. Make sure that the
file pointer is positioned at the start of data to
send before calling :func:`send_file`.
:param mimetype: the mimetype of the file if provided. If a file path is
given, auto detection happens as fallback, otherwise an
error will be raised.
:param as_attachment: set to ``True`` if you want to send this file with
a ``Content-Disposition: attachment`` header.
:param attachment_filename: the filename for the attachment if it
differs from the file's filename.
:param add_etags: set to ``False`` to disable attaching of etags.
:param conditional: set to ``True`` to enable conditional responses.
:param cache_timeout: the timeout in seconds for the headers. When ``None``
(default), this value is set by
:meth:`~Flask.get_send_file_max_age` of
:data:`~flask.current_app`.
:param last_modified: set the ``Last-Modified`` header to this value,
a :class:`~datetime.datetime` or timestamp.
If a file was passed, this overrides its mtime.
"""
mtime = None
fsize = None
if hasattr(filename_or_fp, "__fspath__"):
filename_or_fp = fspath(filename_or_fp)
if isinstance(filename_or_fp, string_types):
filename = filename_or_fp
if not os.path.isabs(filename):
filename = os.path.join(current_app.root_path, filename)
file = None
if attachment_filename is None:
attachment_filename = os.path.basename(filename)
else:
file = filename_or_fp
filename = None
if mimetype is None:
if attachment_filename is not None:
mimetype = (
mimetypes.guess_type(attachment_filename)[0]
or "application/octet-stream"
)
if mimetype is None:
raise ValueError(
"Unable to infer MIME-type because no filename is available. "
"Please set either `attachment_filename`, pass a filepath to "
"`filename_or_fp` or set your own MIME-type via `mimetype`."
)
headers = Headers()
if as_attachment:
if attachment_filename is None:
raise TypeError("filename unavailable, required for sending as attachment")
if not isinstance(attachment_filename, text_type):
attachment_filename = attachment_filename.decode("utf-8")
try:
attachment_filename = attachment_filename.encode("ascii")
except UnicodeEncodeError:
filenames = {
"filename": unicodedata.normalize("NFKD", attachment_filename).encode(
"ascii", "ignore"
),
"filename*": "UTF-8''%s" % url_quote(attachment_filename, safe=b""),
}
else:
filenames = {"filename": attachment_filename}
headers.add("Content-Disposition", "attachment", **filenames)
if current_app.use_x_sendfile and filename:
if file is not None:
file.close()
headers["X-Sendfile"] = filename
fsize = os.path.getsize(filename)
headers["Content-Length"] = fsize
data = None
else:
if file is None:
file = open(filename, "rb")
mtime = os.path.getmtime(filename)
fsize = os.path.getsize(filename)
headers["Content-Length"] = fsize
elif isinstance(file, io.BytesIO):
try:
fsize = file.getbuffer().nbytes
except AttributeError:
# Python 2 doesn't have getbuffer
fsize = len(file.getvalue())
headers["Content-Length"] = fsize
data = wrap_file(request.environ, file)
rv = current_app.response_class(
data, mimetype=mimetype, headers=headers, direct_passthrough=True
)
if last_modified is not None:
rv.last_modified = last_modified
elif mtime is not None:
rv.last_modified = mtime
rv.cache_control.public = True
if cache_timeout is None:
cache_timeout = current_app.get_send_file_max_age(filename)
if cache_timeout is not None:
rv.cache_control.max_age = cache_timeout
rv.expires = int(time() + cache_timeout)
if add_etags and filename is not None:
from warnings import warn
try:
rv.set_etag(
"%s-%s-%s"
% (
os.path.getmtime(filename),
os.path.getsize(filename),
adler32(
filename.encode("utf-8")
if isinstance(filename, text_type)
else filename
)
& 0xFFFFFFFF,
)
)
except OSError:
warn(
"Access %s failed, maybe it does not exist, so ignore etags in "
"headers" % filename,
stacklevel=2,
)
if conditional:
try:
rv = rv.make_conditional(request, accept_ranges=True, complete_length=fsize)
except RequestedRangeNotSatisfiable:
if file is not None:
file.close()
raise
# make sure we don't send x-sendfile for servers that
# ignore the 304 status code for x-sendfile.
if rv.status_code == 304:
rv.headers.pop("x-sendfile", None)
return rv
def safe_join(directory, *pathnames):
"""Safely join `directory` and zero or more untrusted `pathnames`
components.
Example usage::
@app.route('/wiki/<path:filename>')
def wiki_page(filename):
filename = safe_join(app.config['WIKI_FOLDER'], filename)
with open(filename, 'rb') as fd:
content = fd.read() # Read and process the file content...
:param directory: the trusted base directory.
:param pathnames: the untrusted pathnames relative to that directory.
:raises: :class:`~werkzeug.exceptions.NotFound` if one or more passed
paths fall out of its boundaries.
"""
parts = [directory]
for filename in pathnames:
if filename != "":
filename = posixpath.normpath(filename)
if (
any(sep in filename for sep in _os_alt_seps)
or os.path.isabs(filename)
or filename == ".."
or filename.startswith("../")
):
raise NotFound()
parts.append(filename)
return posixpath.join(*parts)
def send_from_directory(directory, filename, **options):
"""Send a file from a given directory with :func:`send_file`. This
is a secure way to quickly expose static files from an upload folder
or something similar.
Example usage::
@app.route('/uploads/<path:filename>')
def download_file(filename):
return send_from_directory(app.config['UPLOAD_FOLDER'],
filename, as_attachment=True)
.. admonition:: Sending files and Performance
It is strongly recommended to activate either ``X-Sendfile`` support in
your webserver or (if no authentication happens) to tell the webserver
to serve files for the given path on its own without calling into the
web application for improved performance.
.. versionadded:: 0.5
:param directory: the directory where all the files are stored.
:param filename: the filename relative to that directory to
download.
:param options: optional keyword arguments that are directly
forwarded to :func:`send_file`.
"""
filename = fspath(filename)
directory = fspath(directory)
filename = safe_join(directory, filename)
if not os.path.isabs(filename):
filename = os.path.join(current_app.root_path, filename)
try:
if not os.path.isfile(filename):
raise NotFound()
except (TypeError, ValueError):
raise BadRequest()
options.setdefault("conditional", True)
return send_file(filename, **options)
def get_root_path(import_name):
"""Returns the path to a package or cwd if that cannot be found. This
returns the path of a package or the folder that contains a module.
Not to be confused with the package path returned by :func:`find_package`.
"""
# Module already imported and has a file attribute. Use that first.
mod = sys.modules.get(import_name)
if mod is not None and hasattr(mod, "__file__"):
return os.path.dirname(os.path.abspath(mod.__file__))
# Next attempt: check the loader.
loader = pkgutil.get_loader(import_name)
# Loader does not exist or we're referring to an unloaded main module
# or a main module without path (interactive sessions), go with the
# current working directory.
if loader is None or import_name == "__main__":
return os.getcwd()
# For .egg, zipimporter does not have get_filename until Python 2.7.
# Some other loaders might exhibit the same behavior.
if hasattr(loader, "get_filename"):
filepath = loader.get_filename(import_name)
else:
# Fall back to imports.
__import__(import_name)
mod = sys.modules[import_name]
filepath = getattr(mod, "__file__", None)
# If we don't have a filepath it might be because we are a
# namespace package. In this case we pick the root path from the
# first module that is contained in our package.
if filepath is None:
raise RuntimeError(
"No root path can be found for the provided "
'module "%s". This can happen because the '
"module came from an import hook that does "
"not provide file name information or because "
"it's a namespace package. In this case "
"the root path needs to be explicitly "
"provided." % import_name
)
# filepath is import_name.py for a module, or __init__.py for a package.
return os.path.dirname(os.path.abspath(filepath))
def _matching_loader_thinks_module_is_package(loader, mod_name):
"""Given the loader that loaded a module and the module this function
attempts to figure out if the given module is actually a package.
"""
# If the loader can tell us if something is a package, we can
# directly ask the loader.
if hasattr(loader, "is_package"):
return loader.is_package(mod_name)
# importlib's namespace loaders do not have this functionality but
# all the modules it loads are packages, so we can take advantage of
# this information.
elif (
loader.__class__.__module__ == "_frozen_importlib"
and loader.__class__.__name__ == "NamespaceLoader"
):
return True
# Otherwise we need to fail with an error that explains what went
# wrong.
raise AttributeError(
(
"%s.is_package() method is missing but is required by Flask of "
"PEP 302 import hooks. If you do not use import hooks and "
"you encounter this error please file a bug against Flask."
)
% loader.__class__.__name__
)
def _find_package_path(root_mod_name):
"""Find the path where the module's root exists in"""
if sys.version_info >= (3, 4):
import importlib.util
try:
spec = importlib.util.find_spec(root_mod_name)
if spec is None:
raise ValueError("not found")
# ImportError: the machinery told us it does not exist
# ValueError:
# - the module name was invalid
# - the module name is __main__
# - *we* raised `ValueError` due to `spec` being `None`
except (ImportError, ValueError):
pass # handled below
else:
# namespace package
if spec.origin in {"namespace", None}:
return os.path.dirname(next(iter(spec.submodule_search_locations)))
# a package (with __init__.py)
elif spec.submodule_search_locations:
return os.path.dirname(os.path.dirname(spec.origin))
# just a normal module
else:
return os.path.dirname(spec.origin)
# we were unable to find the `package_path` using PEP 451 loaders
loader = pkgutil.get_loader(root_mod_name)
if loader is None or root_mod_name == "__main__":
# import name is not found, or interactive/main module
return os.getcwd()
else:
# For .egg, zipimporter does not have get_filename until Python 2.7.
if hasattr(loader, "get_filename"):
filename = loader.get_filename(root_mod_name)
elif hasattr(loader, "archive"):
# zipimporter's loader.archive points to the .egg or .zip
# archive filename is dropped in call to dirname below.
filename = loader.archive
else:
# At least one loader is missing both get_filename and archive:
# Google App Engine's HardenedModulesHook
#
# Fall back to imports.
__import__(root_mod_name)
filename = sys.modules[root_mod_name].__file__
package_path = os.path.abspath(os.path.dirname(filename))
# In case the root module is a package we need to chop of the
# rightmost part. This needs to go through a helper function
# because of python 3.3 namespace packages.
if _matching_loader_thinks_module_is_package(loader, root_mod_name):
package_path = os.path.dirname(package_path)
return package_path
def find_package(import_name):
"""Finds a package and returns the prefix (or None if the package is
not installed) as well as the folder that contains the package or
module as a tuple. The package path returned is the module that would
have to be added to the pythonpath in order to make it possible to
import the module. The prefix is the path below which a UNIX like
folder structure exists (lib, share etc.).
"""
root_mod_name, _, _ = import_name.partition(".")
package_path = _find_package_path(root_mod_name)
site_parent, site_folder = os.path.split(package_path)
py_prefix = os.path.abspath(sys.prefix)
if package_path.startswith(py_prefix):
return py_prefix, package_path
elif site_folder.lower() == "site-packages":
parent, folder = os.path.split(site_parent)
# Windows like installations
if folder.lower() == "lib":
base_dir = parent
# UNIX like installations
elif os.path.basename(parent).lower() == "lib":
base_dir = os.path.dirname(parent)
else:
base_dir = site_parent
return base_dir, package_path
return None, package_path
class locked_cached_property(object):
"""A decorator that converts a function into a lazy property. The
function wrapped is called the first time to retrieve the result
and then that calculated result is used the next time you access
the value. Works like the one in Werkzeug but has a lock for
thread safety.
"""
def __init__(self, func, name=None, doc=None):
self.__name__ = name or func.__name__
self.__module__ = func.__module__
self.__doc__ = doc or func.__doc__
self.func = func
self.lock = RLock()
def __get__(self, obj, type=None):
if obj is None:
return self
with self.lock:
value = obj.__dict__.get(self.__name__, _missing)
if value is _missing:
value = self.func(obj)
obj.__dict__[self.__name__] = value
return value
class _PackageBoundObject(object):
#: 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, template_folder=None, root_path=None):
self.import_name = import_name
self.template_folder = template_folder
if root_path is None:
root_path = get_root_path(self.import_name)
self.root_path = root_path
self._static_folder = None
self._static_url_path = None
# circular import
from .cli import AppGroup
#: The Click command group for registration of CLI commands
#: on the application and associated blueprints. These commands
#: are accessible via the :command:`flask` command once the
#: application has been discovered and blueprints registered.
self.cli = AppGroup()
@property
def static_folder(self):
"""The absolute path to the configured static folder."""
if self._static_folder is not None:
return os.path.join(self.root_path, self._static_folder)
@static_folder.setter
def static_folder(self, value):
if value is not None:
value = value.rstrip("/\\")
self._static_folder = value
@property
def static_url_path(self):
"""The URL prefix that the static route will be accessible from.
If it was not configured during init, it is derived from
:attr:`static_folder`.
"""
if self._static_url_path is not None:
return self._static_url_path
if self.static_folder is not None:
basename = os.path.basename(self.static_folder)
return ("/" + basename).rstrip("/")
@static_url_path.setter
def static_url_path(self, value):
if value is not None:
value = value.rstrip("/")
self._static_url_path = value
@property
def has_static_folder(self):
"""This is ``True`` if the package bound object's container has a
folder for static files.
.. versionadded:: 0.5
"""
return self.static_folder is not None
@locked_cached_property
def jinja_loader(self):
"""The Jinja loader for this package bound object.
.. versionadded:: 0.5
"""
if self.template_folder is not None:
return FileSystemLoader(os.path.join(self.root_path, self.template_folder))
def get_send_file_max_age(self, filename):
"""Provides default cache_timeout for the :func:`send_file` functions.
By default, this function returns ``SEND_FILE_MAX_AGE_DEFAULT`` from
the configuration of :data:`~flask.current_app`.
Static file functions such as :func:`send_from_directory` use this
function, and :func:`send_file` calls this function on
:data:`~flask.current_app` when the given cache_timeout is ``None``. If a
cache_timeout is given in :func:`send_file`, that timeout is used;
otherwise, this method is called.
This allows subclasses to change the behavior when sending files based
on the filename. For example, to set the cache timeout for .js files
to 60 seconds::
class MyFlask(flask.Flask):
def get_send_file_max_age(self, name):
if name.lower().endswith('.js'):
return 60
return flask.Flask.get_send_file_max_age(self, name)
.. versionadded:: 0.9
"""
return total_seconds(current_app.send_file_max_age_default)
def send_static_file(self, filename):
"""Function used internally to send static files from the static
folder to the browser.
.. versionadded:: 0.5
"""
if not self.has_static_folder:
raise RuntimeError("No static folder for this object")
# Ensure get_send_file_max_age is called in all cases.
# Here, we ensure get_send_file_max_age is called for Blueprints.
cache_timeout = self.get_send_file_max_age(filename)
return send_from_directory(
self.static_folder, filename, cache_timeout=cache_timeout
)
def open_resource(self, resource, mode="rb"):
"""Opens a resource from the application's resource folder. To see
how this works, consider the following folder structure::
/myapplication.py
/schema.sql
/static
/style.css
/templates
/layout.html
/index.html
If you want to open the :file:`schema.sql` file you would do the
following::
with app.open_resource('schema.sql') as f:
contents = f.read()
do_something_with(contents)
:param resource: the name of the resource. To access resources within
subfolders use forward slashes as separator.
:param mode: Open file in this mode. Only reading is supported,
valid values are "r" (or "rt") and "rb".
"""
if mode not in {"r", "rt", "rb"}:
raise ValueError("Resources can only be opened for reading")
return open(os.path.join(self.root_path, resource), mode)
def total_seconds(td):
"""Returns the total seconds from a timedelta object.
:param timedelta td: the timedelta to be converted in seconds
:returns: number of seconds
:rtype: int
"""
return td.days * 60 * 60 * 24 + td.seconds
def is_ip(value):
"""Determine if the given string is an IP address.
Python 2 on Windows doesn't provide ``inet_pton``, so this only
checks IPv4 addresses in that environment.
:param value: value to check
:type value: str
:return: True if string is an IP address
:rtype: bool
"""
if PY2 and os.name == "nt":
try:
socket.inet_aton(value)
return True
except socket.error:
return False
for family in (socket.AF_INET, socket.AF_INET6):
try:
socket.inet_pton(family, value)
except socket.error:
pass
else:
return True
return False
env/lib/python3.5/site-packages/flask/json/__init__.py 0 → 100644
View file @ ff4a13ed
# -*- coding: utf-8 -*-
"""
flask.json
~~~~~~~~~~
:copyright: 2010 Pallets
:license: BSD-3-Clause
"""
import codecs
import io
import uuid
from datetime import date
from datetime import datetime
from itsdangerous import json as _json
from jinja2 import Markup
from werkzeug.http import http_date
from .._compat import PY2
from .._compat import text_type
from ..globals import current_app
from ..globals import request
try:
import dataclasses
except ImportError:
dataclasses = None
# Figure out if simplejson escapes slashes. This behavior was changed
# from one version to another without reason.
_slash_escape = "\\/" not in _json.dumps("/")
__all__ = [
"dump",
"dumps",
"load",
"loads",
"htmlsafe_dump",
"htmlsafe_dumps",
"JSONDecoder",
"JSONEncoder",
"jsonify",
]
def _wrap_reader_for_text(fp, encoding):
if isinstance(fp.read(0), bytes):
fp = io.TextIOWrapper(io.BufferedReader(fp), encoding)
return fp
def _wrap_writer_for_text(fp, encoding):
try:
fp.write("")
except TypeError:
fp = io.TextIOWrapper(fp, encoding)
return fp
class JSONEncoder(_json.JSONEncoder):
"""The default Flask JSON encoder. This one extends the default
encoder by also supporting ``datetime``, ``UUID``, ``dataclasses``,
and ``Markup`` objects.
``datetime`` objects are serialized as RFC 822 datetime strings.
This is the same as the HTTP date format.
In order to support more data types, override the :meth:`default`
method.
"""
def default(self, o):
"""Implement this method in a subclass such that it returns a
serializable object for ``o``, or calls the base implementation (to
raise a :exc:`TypeError`).
For example, to support arbitrary iterators, you could implement
default like this::
def default(self, o):
try:
iterable = iter(o)
except TypeError:
pass
else:
return list(iterable)
return JSONEncoder.default(self, o)
"""
if isinstance(o, datetime):
return http_date(o.utctimetuple())
if isinstance(o, date):
return http_date(o.timetuple())
if isinstance(o, uuid.UUID):
return str(o)
if dataclasses and dataclasses.is_dataclass(o):
return dataclasses.asdict(o)
if hasattr(o, "__html__"):
return text_type(o.__html__())
return _json.JSONEncoder.default(self, o)
class JSONDecoder(_json.JSONDecoder):
"""The default JSON decoder. This one does not change the behavior from
the default simplejson decoder. Consult the :mod:`json` documentation
for more information. This decoder is not only used for the load
functions of this module but also :attr:`~flask.Request`.
"""
def _dump_arg_defaults(kwargs, app=None):
"""Inject default arguments for dump functions."""
if app is None:
app = current_app
if app:
bp = app.blueprints.get(request.blueprint) if request else None
kwargs.setdefault(
"cls", bp.json_encoder if bp and bp.json_encoder else app.json_encoder
)
if not app.config["JSON_AS_ASCII"]:
kwargs.setdefault("ensure_ascii", False)
kwargs.setdefault("sort_keys", app.config["JSON_SORT_KEYS"])
else:
kwargs.setdefault("sort_keys", True)
kwargs.setdefault("cls", JSONEncoder)
def _load_arg_defaults(kwargs, app=None):
"""Inject default arguments for load functions."""
if app is None:
app = current_app
if app:
bp = app.blueprints.get(request.blueprint) if request else None
kwargs.setdefault(
"cls", bp.json_decoder if bp and bp.json_decoder else app.json_decoder
)
else:
kwargs.setdefault("cls", JSONDecoder)
def detect_encoding(data):
"""Detect which UTF codec was used to encode the given bytes.
The latest JSON standard (:rfc:`8259`) suggests that only UTF-8 is
accepted. Older documents allowed 8, 16, or 32. 16 and 32 can be big
or little endian. Some editors or libraries may prepend a BOM.
:param data: Bytes in unknown UTF encoding.
:return: UTF encoding name
"""
head = data[:4]
if head[:3] == codecs.BOM_UTF8:
return "utf-8-sig"
if b"\x00" not in head:
return "utf-8"
if head in (codecs.BOM_UTF32_BE, codecs.BOM_UTF32_LE):
return "utf-32"
if head[:2] in (codecs.BOM_UTF16_BE, codecs.BOM_UTF16_LE):
return "utf-16"
if len(head) == 4:
if head[:3] == b"\x00\x00\x00":
return "utf-32-be"
if head[::2] == b"\x00\x00":
return "utf-16-be"
if head[1:] == b"\x00\x00\x00":
return "utf-32-le"
if head[1::2] == b"\x00\x00":
return "utf-16-le"
if len(head) == 2:
return "utf-16-be" if head.startswith(b"\x00") else "utf-16-le"
return "utf-8"
def dumps(obj, app=None, **kwargs):
"""Serialize ``obj`` to a JSON-formatted string. If there is an
app context pushed, use the current app's configured encoder
(:attr:`~flask.Flask.json_encoder`), or fall back to the default
:class:`JSONEncoder`.
Takes the same arguments as the built-in :func:`json.dumps`, and
does some extra configuration based on the application. If the
simplejson package is installed, it is preferred.
:param obj: Object to serialize to JSON.
:param app: App instance to use to configure the JSON encoder.
Uses ``current_app`` if not given, and falls back to the default
encoder when not in an app context.
:param kwargs: Extra arguments passed to :func:`json.dumps`.
.. versionchanged:: 1.0.3
``app`` can be passed directly, rather than requiring an app
context for configuration.
"""
_dump_arg_defaults(kwargs, app=app)
encoding = kwargs.pop("encoding", None)
rv = _json.dumps(obj, **kwargs)
if encoding is not None and isinstance(rv, text_type):
rv = rv.encode(encoding)
return rv
def dump(obj, fp, app=None, **kwargs):
"""Like :func:`dumps` but writes into a file object."""
_dump_arg_defaults(kwargs, app=app)
encoding = kwargs.pop("encoding", None)
if encoding is not None:
fp = _wrap_writer_for_text(fp, encoding)
_json.dump(obj, fp, **kwargs)
def loads(s, app=None, **kwargs):
"""Deserialize an object from a JSON-formatted string ``s``. If
there is an app context pushed, use the current app's configured
decoder (:attr:`~flask.Flask.json_decoder`), or fall back to the
default :class:`JSONDecoder`.
Takes the same arguments as the built-in :func:`json.loads`, and
does some extra configuration based on the application. If the
simplejson package is installed, it is preferred.
:param s: JSON string to deserialize.
:param app: App instance to use to configure the JSON decoder.
Uses ``current_app`` if not given, and falls back to the default
encoder when not in an app context.
:param kwargs: Extra arguments passed to :func:`json.dumps`.
.. versionchanged:: 1.0.3
``app`` can be passed directly, rather than requiring an app
context for configuration.
"""
_load_arg_defaults(kwargs, app=app)
if isinstance(s, bytes):
encoding = kwargs.pop("encoding", None)
if encoding is None:
encoding = detect_encoding(s)
s = s.decode(encoding)
return _json.loads(s, **kwargs)
def load(fp, app=None, **kwargs):
"""Like :func:`loads` but reads from a file object."""
_load_arg_defaults(kwargs, app=app)
if not PY2:
fp = _wrap_reader_for_text(fp, kwargs.pop("encoding", None) or "utf-8")
return _json.load(fp, **kwargs)
def htmlsafe_dumps(obj, **kwargs):
"""Works exactly like :func:`dumps` but is safe for use in ``<script>``
tags. It accepts the same arguments and returns a JSON string. Note that
this is available in templates through the ``|tojson`` filter which will
also mark the result as safe. Due to how this function escapes certain
characters this is safe even if used outside of ``<script>`` tags.
The following characters are escaped in strings:
- ``<``
- ``>``
- ``&``
- ``'``
This makes it safe to embed such strings in any place in HTML with the
notable exception of double quoted attributes. In that case single
quote your attributes or HTML escape it in addition.
.. versionchanged:: 0.10
This function's return value is now always safe for HTML usage, even
if outside of script tags or if used in XHTML. This rule does not
hold true when using this function in HTML attributes that are double
quoted. Always single quote attributes if you use the ``|tojson``
filter. Alternatively use ``|tojson|forceescape``.
"""
rv = (
dumps(obj, **kwargs)
.replace(u"<", u"\\u003c")
.replace(u">", u"\\u003e")
.replace(u"&", u"\\u0026")
.replace(u"'", u"\\u0027")
)
if not _slash_escape:
rv = rv.replace("\\/", "/")
return rv
def htmlsafe_dump(obj, fp, **kwargs):
"""Like :func:`htmlsafe_dumps` but writes into a file object."""
fp.write(text_type(htmlsafe_dumps(obj, **kwargs)))
def jsonify(*args, **kwargs):
"""This function wraps :func:`dumps` to add a few enhancements that make
life easier. It turns the JSON output into a :class:`~flask.Response`
object with the :mimetype:`application/json` mimetype. For convenience, it
also converts multiple arguments into an array or multiple keyword arguments
into a dict. This means that both ``jsonify(1,2,3)`` and
``jsonify([1,2,3])`` serialize to ``[1,2,3]``.
For clarity, the JSON serialization behavior has the following differences
from :func:`dumps`:
1. Single argument: Passed straight through to :func:`dumps`.
2. Multiple arguments: Converted to an array before being passed to
:func:`dumps`.
3. Multiple keyword arguments: Converted to a dict before being passed to
:func:`dumps`.
4. Both args and kwargs: Behavior undefined and will throw an exception.
Example usage::
from flask import jsonify
@app.route('/_get_current_user')
def get_current_user():
return jsonify(username=g.user.username,
email=g.user.email,
id=g.user.id)
This will send a JSON response like this to the browser::
{
"username": "admin",
"email": "admin@localhost",
"id": 42
}
.. versionchanged:: 0.11
Added support for serializing top-level arrays. This introduces a
security risk in ancient browsers. See :ref:`json-security` for details.
This function's response will be pretty printed if the
``JSONIFY_PRETTYPRINT_REGULAR`` config parameter is set to True or the
Flask app is running in debug mode. Compressed (not pretty) formatting
currently means no indents and no spaces after separators.
.. versionadded:: 0.2
"""
indent = None
separators = (",", ":")
if current_app.config["JSONIFY_PRETTYPRINT_REGULAR"] or current_app.debug:
indent = 2
separators = (", ", ": ")
if args and kwargs:
raise TypeError("jsonify() behavior undefined when passed both args and kwargs")
elif len(args) == 1: # single args are passed directly to dumps()
data = args[0]
else:
data = args or kwargs
return current_app.response_class(
dumps(data, indent=indent, separators=separators) + "\n",
mimetype=current_app.config["JSONIFY_MIMETYPE"],
)
def tojson_filter(obj, **kwargs):
return Markup(htmlsafe_dumps(obj, **kwargs))
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