custom flask code!

app.py

""" the problem is, we want to be able to change session life time of a flask app,
on the fly, without restarting the app. the reason for this is, that the app was 
being used as a UI for a networking device, customers were able to use our app 
instead of using a terminal to config the device. so, we thought it would be a
better UX thing to not restart the application, on session time change.

i was tasked to solve the problem, and this is how i approached it:
i checked the source code of flask to see how it works, and set the session life
time.

    #: A :class:`~datetime.timedelta` which is used to set the expiration
    #: date of a permanent session. The default is 31 days which makes a
    #: permanent session survive for roughly one month.
    #:
    #: This attribute can also be configured from the config with the
    #: ``PERMANENT_SESSION_LIFETIME`` configuration key. Defaults to
    #: ``timedelta(days=31)``
    permanent_session_lifetime = ConfigAttribute('PERMANENT_SESSION_LIFETIME',
    get_converter=_make_timedelta)
    
the above, is what i found on the source code, so i thought, if i could change
this behaviour, all problems would be fixed.

i searched a bit more to find out how this is being used to determine the 
session life time on each request.

    def get_expiration_time(self, app, session):
    """A helper method that returns an expiration date for the session
    or ``None`` if the session is linked to the browser session. The
    default implementation returns now + the permanent session
    lifetime configured on the application.
    """
    if session.permanent:

    return datetime.utcnow() + app.permanent_session_lifetime

i found the above code on another file, and got the idea: i would inherit the 
base `Flask` class and edit the code on it. so:

    class New_Flask(Flask):

        permanent_session_lifetime = datetime.timedelta(minutes=3)
        
this obviously is not the actual code that i used, but this is the code that shows how i
handled the problem. there may be better ways, but i liked the way i did it, and since
then, the app is working just fine. (the actual code has exception handling and some
conditionals for where the session time is 0 or is a very large number, i only allow numbers
between 0-60, with 0 being infinite session life time.
i didn't have access to actual code that i wrote, because it's on our company's private git
server. i am not allowed to get out any of the code.
"""