views.py — flask Source File

Source Code

from __future__ import annotations

import typing as t

from . import typing as ft
from .globals import current_app
from .globals import request

F = t.TypeVar("F", bound=t.Callable[..., t.Any])

http_method_funcs = frozenset(
    ["get", "post", "head", "options", "delete", "put", "trace", "patch"]
)


class View:
    """Subclass this class and override :meth:`dispatch_request` to
    create a generic class-based view. Call :meth:`as_view` to create a
    view function that creates an instance of the class with the given
    arguments and calls its ``dispatch_request`` method with any URL
    variables.

    See :doc:`views` for a detailed guide.

    .. code-block:: python

        class Hello(View):
            init_every_request = False

            def dispatch_request(self, name):
                return f"Hello, {name}!"

        app.add_url_rule(
            "/hello/<name>", view_func=Hello.as_view("hello")
        )

    Set :attr:`methods` on the class to change what methods the view
    accepts.

    Set :attr:`decorators` on the class to apply a list of decorators to
    the generated view function. Decorators applied to the class itself
    will not be applied to the generated view function!

    Set :attr:`init_every_request` to ``False`` for efficiency, unless
    you need to store request-global data on ``self``.
    """

    #: The methods this view is registered for. Uses the same default
    #: (``["GET", "HEAD", "OPTIONS"]``) as ``route`` and
    #: ``add_url_rule`` by default.
    methods: t.ClassVar[t.Collection[str] | None] = None

    #: Control whether the ``OPTIONS`` method is handled automatically.
    #: Uses the same default (``True``) as ``route`` and
    #: ``add_url_rule`` by default.
    provide_automatic_options: t.ClassVar[bool | None] = None

    #: A list of decorators to apply, in order, to the generated view
    #: function. Remember that ``@decorator`` syntax is applied bottom
    #: to top, so the first decorator in the list would be the bottom
// ... (132 more lines)