NullSession Class — flask Architecture

Architecture documentation for the NullSession class in sessions.py from the flask codebase.

Class python ApplicationCore

Entity Profile

ApplicationCore→ NullSession Class — flask Architecture

Dependency Diagram

graph TD
  e6d2f5d8_e726_9621_7d71_383a6d282b0a["NullSession"]
  d7fb9d4d_3951_5244_a49f_6217614cd3a9["SecureCookieSession"]
  e6d2f5d8_e726_9621_7d71_383a6d282b0a -->|extends| d7fb9d4d_3951_5244_a49f_6217614cd3a9
  f793a407_79ea_667a_f29e_29bbf57c781f["sessions.py"]
  e6d2f5d8_e726_9621_7d71_383a6d282b0a -->|defined in| f793a407_79ea_667a_f29e_29bbf57c781f
  f43e15f7_ede6_c2fb_00c4_1319cca2b8e5["_fail()"]
  e6d2f5d8_e726_9621_7d71_383a6d282b0a -->|method| f43e15f7_ede6_c2fb_00c4_1319cca2b8e5

Relationship Graph

Source Code

src/flask/sessions.py lines 97–111

class NullSession(SecureCookieSession):
    """Class used to generate nicer error messages if sessions are not
    available.  Will still allow read-only access to the empty session
    but fail on setting.
    """

    def _fail(self, *args: t.Any, **kwargs: t.Any) -> t.NoReturn:
        raise RuntimeError(
            "The session is unavailable because no secret "
            "key was set.  Set the secret_key on the "
            "application to something unique and secret."
        )

    __setitem__ = __delitem__ = clear = pop = popitem = update = setdefault = _fail
    del _fail