You cannot select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
439 lines
14 KiB
Python
439 lines
14 KiB
Python
import contextvars
|
|
import sys
|
|
import typing as t
|
|
from functools import update_wrapper
|
|
from types import TracebackType
|
|
|
|
from werkzeug.exceptions import HTTPException
|
|
|
|
from . import typing as ft
|
|
from .globals import _cv_app
|
|
from .globals import _cv_request
|
|
from .signals import appcontext_popped
|
|
from .signals import appcontext_pushed
|
|
|
|
if t.TYPE_CHECKING: # pragma: no cover
|
|
from .app import Flask
|
|
from .sessions import SessionMixin
|
|
from .wrappers import Request
|
|
|
|
|
|
# a singleton sentinel value for parameter defaults
|
|
_sentinel = object()
|
|
|
|
|
|
class _AppCtxGlobals:
|
|
"""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
|
|
"""
|
|
|
|
# Define attr methods to let mypy know this is a namespace object
|
|
# that has arbitrary attributes.
|
|
|
|
def __getattr__(self, name: str) -> t.Any:
|
|
try:
|
|
return self.__dict__[name]
|
|
except KeyError:
|
|
raise AttributeError(name) from None
|
|
|
|
def __setattr__(self, name: str, value: t.Any) -> None:
|
|
self.__dict__[name] = value
|
|
|
|
def __delattr__(self, name: str) -> None:
|
|
try:
|
|
del self.__dict__[name]
|
|
except KeyError:
|
|
raise AttributeError(name) from None
|
|
|
|
def get(self, name: str, default: t.Optional[t.Any] = None) -> t.Any:
|
|
"""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: str, default: t.Any = _sentinel) -> t.Any:
|
|
"""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 raising 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: str, default: t.Any = None) -> t.Any:
|
|
"""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: str) -> bool:
|
|
return item in self.__dict__
|
|
|
|
def __iter__(self) -> t.Iterator[str]:
|
|
return iter(self.__dict__)
|
|
|
|
def __repr__(self) -> str:
|
|
ctx = _cv_app.get(None)
|
|
if ctx is not None:
|
|
return f"<flask.g of '{ctx.app.name}'>"
|
|
return object.__repr__(self)
|
|
|
|
|
|
def after_this_request(f: ft.AfterRequestCallable) -> ft.AfterRequestCallable:
|
|
"""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
|
|
"""
|
|
ctx = _cv_request.get(None)
|
|
|
|
if ctx is None:
|
|
raise RuntimeError(
|
|
"'after_this_request' can only be used when a request"
|
|
" context is active, such as in a view function."
|
|
)
|
|
|
|
ctx._after_request_functions.append(f)
|
|
return f
|
|
|
|
|
|
def copy_current_request_context(f: t.Callable) -> t.Callable:
|
|
"""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
|
|
"""
|
|
ctx = _cv_request.get(None)
|
|
|
|
if ctx is None:
|
|
raise RuntimeError(
|
|
"'copy_current_request_context' can only be used when a"
|
|
" request context is active, such as in a view function."
|
|
)
|
|
|
|
ctx = ctx.copy()
|
|
|
|
def wrapper(*args, **kwargs):
|
|
with ctx:
|
|
return ctx.app.ensure_sync(f)(*args, **kwargs)
|
|
|
|
return update_wrapper(wrapper, f)
|
|
|
|
|
|
def has_request_context() -> bool:
|
|
"""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 _cv_request.get(None) is not None
|
|
|
|
|
|
def has_app_context() -> bool:
|
|
"""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 _cv_app.get(None) is not None
|
|
|
|
|
|
class AppContext:
|
|
"""The app context contains application-specific information. An app
|
|
context is created and pushed at the beginning of each request if
|
|
one is not already active. An app context is also pushed when
|
|
running CLI commands.
|
|
"""
|
|
|
|
def __init__(self, app: "Flask") -> None:
|
|
self.app = app
|
|
self.url_adapter = app.create_url_adapter(None)
|
|
self.g: _AppCtxGlobals = app.app_ctx_globals_class()
|
|
self._cv_tokens: t.List[contextvars.Token] = []
|
|
|
|
def push(self) -> None:
|
|
"""Binds the app context to the current context."""
|
|
self._cv_tokens.append(_cv_app.set(self))
|
|
appcontext_pushed.send(self.app)
|
|
|
|
def pop(self, exc: t.Optional[BaseException] = _sentinel) -> None: # type: ignore
|
|
"""Pops the app context."""
|
|
try:
|
|
if len(self._cv_tokens) == 1:
|
|
if exc is _sentinel:
|
|
exc = sys.exc_info()[1]
|
|
self.app.do_teardown_appcontext(exc)
|
|
finally:
|
|
ctx = _cv_app.get()
|
|
_cv_app.reset(self._cv_tokens.pop())
|
|
|
|
if ctx is not self:
|
|
raise AssertionError(
|
|
f"Popped wrong app context. ({ctx!r} instead of {self!r})"
|
|
)
|
|
|
|
appcontext_popped.send(self.app)
|
|
|
|
def __enter__(self) -> "AppContext":
|
|
self.push()
|
|
return self
|
|
|
|
def __exit__(
|
|
self,
|
|
exc_type: t.Optional[type],
|
|
exc_value: t.Optional[BaseException],
|
|
tb: t.Optional[TracebackType],
|
|
) -> None:
|
|
self.pop(exc_value)
|
|
|
|
|
|
class RequestContext:
|
|
"""The request context contains per-request information. The Flask
|
|
app creates and pushes it at the beginning of the request, then pops
|
|
it at the end of the request. 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. When using the interactive debugger, the context will be
|
|
restored so ``request`` is still accessible. Similarly, the test
|
|
client can preserve the context after the request ends. However,
|
|
teardown functions may already have closed some resources such as
|
|
database connections.
|
|
"""
|
|
|
|
def __init__(
|
|
self,
|
|
app: "Flask",
|
|
environ: dict,
|
|
request: t.Optional["Request"] = None,
|
|
session: t.Optional["SessionMixin"] = None,
|
|
) -> None:
|
|
self.app = app
|
|
if request is None:
|
|
request = app.request_class(environ)
|
|
request.json_module = app.json # type: ignore[misc]
|
|
self.request: 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: t.Optional[t.List[t.Tuple[str, str]]] = None
|
|
self.session: t.Optional["SessionMixin"] = session
|
|
# 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: t.List[ft.AfterRequestCallable] = []
|
|
|
|
self._cv_tokens: t.List[t.Tuple[contextvars.Token, t.Optional[AppContext]]] = []
|
|
|
|
def copy(self) -> "RequestContext":
|
|
"""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) -> None:
|
|
"""Can be overridden by a subclass to hook into the matching
|
|
of the request.
|
|
"""
|
|
try:
|
|
result = self.url_adapter.match(return_rule=True) # type: ignore
|
|
self.request.url_rule, self.request.view_args = result # type: ignore
|
|
except HTTPException as e:
|
|
self.request.routing_exception = e
|
|
|
|
def push(self) -> None:
|
|
# Before we push the request context we have to ensure that there
|
|
# is an application context.
|
|
app_ctx = _cv_app.get(None)
|
|
|
|
if app_ctx is None or app_ctx.app is not self.app:
|
|
app_ctx = self.app.app_context()
|
|
app_ctx.push()
|
|
else:
|
|
app_ctx = None
|
|
|
|
self._cv_tokens.append((_cv_request.set(self), app_ctx))
|
|
|
|
# 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)
|
|
|
|
# Match the request URL after loading the session, so that the
|
|
# session is available in custom URL converters.
|
|
if self.url_adapter is not None:
|
|
self.match_request()
|
|
|
|
def pop(self, exc: t.Optional[BaseException] = _sentinel) -> None: # type: ignore
|
|
"""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.
|
|
"""
|
|
clear_request = len(self._cv_tokens) == 1
|
|
|
|
try:
|
|
if clear_request:
|
|
if exc is _sentinel:
|
|
exc = sys.exc_info()[1]
|
|
self.app.do_teardown_request(exc)
|
|
|
|
request_close = getattr(self.request, "close", None)
|
|
if request_close is not None:
|
|
request_close()
|
|
finally:
|
|
ctx = _cv_request.get()
|
|
token, app_ctx = self._cv_tokens.pop()
|
|
_cv_request.reset(token)
|
|
|
|
# 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:
|
|
ctx.request.environ["werkzeug.request"] = None
|
|
|
|
if app_ctx is not None:
|
|
app_ctx.pop(exc)
|
|
|
|
if ctx is not self:
|
|
raise AssertionError(
|
|
f"Popped wrong request context. ({ctx!r} instead of {self!r})"
|
|
)
|
|
|
|
def __enter__(self) -> "RequestContext":
|
|
self.push()
|
|
return self
|
|
|
|
def __exit__(
|
|
self,
|
|
exc_type: t.Optional[type],
|
|
exc_value: t.Optional[BaseException],
|
|
tb: t.Optional[TracebackType],
|
|
) -> None:
|
|
self.pop(exc_value)
|
|
|
|
def __repr__(self) -> str:
|
|
return (
|
|
f"<{type(self).__name__} {self.request.url!r}"
|
|
f" [{self.request.method}] of {self.app.name}>"
|
|
)
|