wrappers.py

import typing as t

from werkzeug.exceptions import BadRequest
from werkzeug.wrappers import Request as RequestBase
from werkzeug.wrappers import Response as ResponseBase

from . import json
from .globals import current_app
from .helpers import _split_blueprint_path

if t.TYPE_CHECKING:
    from werkzeug.routing import Rule


class Request(RequestBase):
    """The request object used by default in Flask.  Remembers the
    matched endpoint and view arguments.

    It is what ends up as :class:`~flask.request`.  If you want to replace
    the request object used you can subclass this and set
    :attr:`~flask.Flask.request_class` to your subclass.

    The request object is a :class:`~werkzeug.wrappers.Request` subclass and
    provides all of the attributes Werkzeug defines plus a few Flask
    specific ones.
    """

    json_module = json

    #: The internal URL rule that matched the request.  This can be
    #: useful to inspect which methods are allowed for the URL from
    #: a before/after handler (``request.url_rule.methods``) etc.
    #: Though if the request's method was invalid for the URL rule,
    #: the valid list is available in ``routing_exception.valid_methods``
    #: instead (an attribute of the Werkzeug exception
    #: :exc:`~werkzeug.exceptions.MethodNotAllowed`)
    #: because the request was never internally bound.
    #:
    #: .. versionadded:: 0.6
    url_rule: t.Optional["Rule"] = None

    #: A dict of view arguments that matched the request.  If an exception
    #: happened when matching, this will be ``None``.
    view_args: t.Optional[t.Dict[str, t.Any]] = None

    #: If matching the URL failed, this is the exception that will be
    #: raised / was raised as part of the request handling.  This is
    #: usually a :exc:`~werkzeug.exceptions.NotFound` exception or
    #: something similar.
    routing_exception: t.Optional[Exception] = None

    @property
    def max_content_length(self) -> t.Optional[int]:  # type: ignore
        """Read-only view of the ``MAX_CONTENT_LENGTH`` config key."""
        if current_app:
            return current_app.config["MAX_CONTENT_LENGTH"]
        else:
            return None

    @property
    def endpoint(self) -> t.Optional[str]:
        """The endpoint that matched the request URL.

        This will be ``None`` if matching failed or has not been
        performed yet.

        This in combination with :attr:`view_args` can be used to
        reconstruct the same URL or a modified URL.
        """
        if self.url_rule is not None:
            return self.url_rule.endpoint

        return None

    @property
    def blueprint(self) -> t.Optional[str]:
        """The registered name of the current blueprint.

        This will be ``None`` if the endpoint is not part of a
        blueprint, or if URL matching failed or has not been performed
        yet.

        This does not necessarily match the name the blueprint was
        created with. It may have been nested, or registered with a
        different name.
        """
        endpoint = self.endpoint

        if endpoint is not None and "." in endpoint:
            return endpoint.rpartition(".")[0]

        return None

    @property
    def blueprints(self) -> t.List[str]:
        """The registered names of the current blueprint upwards through
        parent blueprints.

        This will be an empty list if there is no current blueprint, or
        if URL matching failed.

        .. versionadded:: 2.0.1
        """
        name = self.blueprint

        if name is None:
            return []

        return _split_blueprint_path(name)

    def _load_form_data(self) -> None:
        super()._load_form_data()

        # In debug mode we're replacing the files multidict with an ad-hoc
        # subclass that raises a different error for key errors.
        if (
            current_app
            and current_app.debug
            and self.mimetype != "multipart/form-data"
            and not self.files
        ):
            from .debughelpers import attach_enctype_error_multidict

            attach_enctype_error_multidict(self)

    def on_json_loading_failed(self, e: ValueError) -> t.Any:
        try:
            return super().on_json_loading_failed(e)
        except BadRequest as e:
            if current_app and current_app.debug:
                raise

            raise BadRequest() from e


class Response(ResponseBase):
    """The response object that is used by default in Flask.  Works like the
    response object from Werkzeug but is set to have an HTML mimetype by
    default.  Quite often you don't have to create this object yourself because
    :meth:`~flask.Flask.make_response` will take care of that for you.

    If you want to replace the response object used you can subclass this and
    set :attr:`~flask.Flask.response_class` to your subclass.

    .. versionchanged:: 1.0
        JSON support is added to the response, like the request. This is useful
        when testing to get the test client response data as JSON.

    .. versionchanged:: 1.0

        Added :attr:`max_cookie_size`.
    """

    default_mimetype = "text/html"

    json_module = json

    autocorrect_location_header = False

    @property
    def max_cookie_size(self) -> int:  # type: ignore
        """Read-only view of the :data:`MAX_COOKIE_SIZE` config key.

        See :attr:`~werkzeug.wrappers.Response.max_cookie_size` in
        Werkzeug's docs.
        """
        if current_app:
            return current_app.config["MAX_COOKIE_SIZE"]

        # return Werkzeug's default when not in an app context
        return super().max_cookie_size