flask/src/flask/blueprints.py
pgjones 0ec7f713d6 Split the App and Blueprint into Sansio and IO parts
This follows a similar structure in Werkzeug and allows for async
based IO projects, specifically Quart, to base themselves on
Flask.

Note that the globals, and signals are specific to Flask and hence
specific to Flask's IO. This means they cannot be moved to the sansio
part of the codebase.
2023-08-19 18:35:14 +01:00

91 lines
3.1 KiB
Python

from __future__ import annotations
import os
import typing as t
from datetime import timedelta
from .globals import current_app
from .helpers import send_from_directory
from .sansio.blueprints import Blueprint as SansioBlueprint
from .sansio.blueprints import BlueprintSetupState as BlueprintSetupState # noqa
if t.TYPE_CHECKING: # pragma: no cover
from .wrappers import Response
class Blueprint(SansioBlueprint):
def get_send_file_max_age(self, filename: str | None) -> int | None:
"""Used by :func:`send_file` to determine the ``max_age`` cache
value for a given file path if it wasn't passed.
By default, this returns :data:`SEND_FILE_MAX_AGE_DEFAULT` from
the configuration of :data:`~flask.current_app`. This defaults
to ``None``, which tells the browser to use conditional requests
instead of a timed cache, which is usually preferable.
Note this is a duplicate of the same method in the Flask
class.
.. versionchanged:: 2.0
The default configuration is ``None`` instead of 12 hours.
.. versionadded:: 0.9
"""
value = current_app.config["SEND_FILE_MAX_AGE_DEFAULT"]
if value is None:
return None
if isinstance(value, timedelta):
return int(value.total_seconds())
return value
def send_static_file(self, filename: str) -> Response:
"""The view function used to serve files from
:attr:`static_folder`. A route is automatically registered for
this view at :attr:`static_url_path` if :attr:`static_folder` is
set.
Note this is a duplicate of the same method in the Flask
class.
.. versionadded:: 0.5
"""
if not self.has_static_folder:
raise RuntimeError("'static_folder' must be set to serve static_files.")
# send_file only knows to call get_send_file_max_age on the app,
# call it here so it works for blueprints too.
max_age = self.get_send_file_max_age(filename)
return send_from_directory(
t.cast(str, self.static_folder), filename, max_age=max_age
)
def open_resource(self, resource: str, mode: str = "rb") -> t.IO[t.AnyStr]:
"""Open a resource file relative to :attr:`root_path` for
reading.
For example, if the file ``schema.sql`` is next to the file
``app.py`` where the ``Flask`` app is defined, it can be opened
with:
.. code-block:: python
with app.open_resource("schema.sql") as f:
conn.executescript(f.read())
:param resource: Path to the resource relative to
:attr:`root_path`.
:param mode: Open the file in this mode. Only reading is
supported, valid values are "r" (or "rt") and "rb".
Note this is a duplicate of the same method in the Flask
class.
"""
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)