SessionCheckpoint

from flask_imp.security import SessionCheckpoint

SessionCheckpoint(
    session_key: str,
    values_allowed: t.Union[t.List[t.Union[str, int, bool]], str, int, bool],
).action(
    fail_url: t.Optional[t.Union[str, t.Callable[[], t.Any]]] = None,
    fail_json: t.Optional[t.Dict[str, t.Any]] = None,
    fail_response: t.Optional[t.Callable[[], Response]] = None,
    fail_status: int = 403,
    pass_url: t.Optional[t.Union[str, t.Callable[[], t.Any]]] = None,
    message: t.Optional[str] = None,
    message_category: str = "message",
    disable_default_fail: bool = False
)

---

A checkpoint that checks if the specified session key exists and its value(s) match the specified value(s).

session_key The session key to check for.

values_allowed A list of or singular value(s) that the session key must contain.

.action(...):

pass_url The url to redirect to if the key value passes.

fail_url The url to redirect to if the key value fails.

fail_json JSON that is returned on failure.

fail_response A callable that returns a Flask Response on failure.

fail_status The status code to return if the check fails, defaults to 403.

message If a message is specified, a flash message is shown.

message_category The category of the flash message.

If fail_json is provided, passing to endpoints will be disabled.

pass_url and fail_url take either a string or the utilities.lazy_url_for function.

Examples:

LOG_IN_REQ = SessionCheckpoint(
    "logged_in", True
).action(
    lazy_url_for("login_page"),
    message="Login required for this page!"
)


@bp.route("/admin", methods=["GET"])
@checkpoint(LOG_IN_REQ)
def admin_page():
    ...

Example of multiple checks:

LOG_IN_REQ = SessionCheckpoint(
    session_key="logged_in",
    values_allowed=True,
).action(
    fail_url=lazy_url_for("blueprint.login_page"),
    message="Login needed"  # This will set Flask's flash message
)

ADMIN_PERM = SessionCheckpoint(
    session_key="user_type",
    values_allowed="admin",
).action(
    fail_url=lazy_url_for("blueprint.index"),
    message="You need to be an admin to access this page"
)


@bp.route("/admin", methods=["GET"])
@checkpoint(LOG_IN_REQ)
@checkpoint(ADMIN_PERM)
def admin_page():
    ...

Example of a route that if the user is already logged in, redirects to the specified endpoint:

IS_LOGGED_IN = SessionCheckpoint(
    session_key='logged_in',
    values_allowed=True,
).action(
    pass_endpoint='blueprint.admin_page',
    message="Already logged in",
    disable_default_fail=True
)


@bp.route("/login-page", methods=["GET"])
@checkpoint(IS_LOGGED_IN)
def login_page():
    ...