venv/lib/python3.11/site-packages/flask/blueprints.py

   1 from __future__ import annotations
   2
   3 import os
   4 import typing as t
   5 from datetime import timedelta
   6
   7 from .globals import current_app
   8 from .helpers import send_from_directory
   9 from .sansio.blueprints import Blueprint as SansioBlueprint
  10 from .sansio.blueprints import BlueprintSetupState as BlueprintSetupState  # noqa
  11
  12 if t.TYPE_CHECKING:  # pragma: no cover
  13     from .wrappers import Response
  14
  15
  16 class Blueprint(SansioBlueprint):
  17     def get_send_file_max_age(self, filename: str | None) -> int | None:
  18         """Used by :func:`send_file` to determine the ``max_age`` cache
  19         value for a given file path if it wasn't passed.
  20
  21         By default, this returns :data:`SEND_FILE_MAX_AGE_DEFAULT` from
  22         the configuration of :data:`~flask.current_app`. This defaults
  23         to ``None``, which tells the browser to use conditional requests
  24         instead of a timed cache, which is usually preferable.
  25
  26         Note this is a duplicate of the same method in the Flask
  27         class.
  28
  29         .. versionchanged:: 2.0
  30             The default configuration is ``None`` instead of 12 hours.
  31
  32         .. versionadded:: 0.9
  33         """
  34         value = current_app.config["SEND_FILE_MAX_AGE_DEFAULT"]
  35
  36         if value is None:
  37             return None
  38
  39         if isinstance(value, timedelta):
  40             return int(value.total_seconds())
  41
  42         return value
  43
  44     def send_static_file(self, filename: str) -> Response:
  45         """The view function used to serve files from
  46         :attr:`static_folder`. A route is automatically registered for
  47         this view at :attr:`static_url_path` if :attr:`static_folder` is
  48         set.
  49
  50         Note this is a duplicate of the same method in the Flask
  51         class.
  52
  53         .. versionadded:: 0.5
  54
  55         """
  56         if not self.has_static_folder:
  57             raise RuntimeError("'static_folder' must be set to serve static_files.")
  58
  59         # send_file only knows to call get_send_file_max_age on the app,
  60         # call it here so it works for blueprints too.
  61         max_age = self.get_send_file_max_age(filename)
  62         return send_from_directory(
  63             t.cast(str, self.static_folder), filename, max_age=max_age
  64         )
  65
  66     def open_resource(self, resource: str, mode: str = "rb") -> t.IO[t.AnyStr]:
  67         """Open a resource file relative to :attr:`root_path` for
  68         reading.
  69
  70         For example, if the file ``schema.sql`` is next to the file
  71         ``app.py`` where the ``Flask`` app is defined, it can be opened
  72         with:
  73
  74         .. code-block:: python
  75
  76             with app.open_resource("schema.sql") as f:
  77                 conn.executescript(f.read())
  78
  79         :param resource: Path to the resource relative to
  80             :attr:`root_path`.
  81         :param mode: Open the file in this mode. Only reading is
  82             supported, valid values are "r" (or "rt") and "rb".
  83
  84         Note this is a duplicate of the same method in the Flask
  85         class.
  86
  87         """
  88         if mode not in {"r", "rt", "rb"}:
  89             raise ValueError("Resources can only be opened for reading.")
  90
  91         return open(os.path.join(self.root_path, resource), mode)