12.1.2. An example of logon and logoff handling

This example shows how to work with log on and off handling.

To make logon handling code sample executable and see how it works you should do the following.

Rename logon.py.template to logon.py (see chapter Extendable Python module templates)

Uncomment the function call sample in the logon.py file:

import cerebro
import examples

def logon():

The module of logon handling example is located in examples/logon.py (See chapter File Structure)


# -*- coding: utf-8 -*-
The example shows a function calling timer launch on Cerebro logon.
The function called by timer checks if there are tasks in the user's task list,
which start shortly. If they are, the user is shown a notification.


logon() - is called on Cerebro logon
check_start_tasks() - is called by timer and checks the user's task list

import cerebro
import datetime

def logon():
        # Starting the timer to call the        check_start_tasks function
        cerebro.core.start_timer('examples.logon.check_start_tasks', 1800000)
        # The check_start_tasks function will be called every 30 minutes

def check_start_tasks():

        # getting the current user's task list
        current_user = cerebro.core.user_profile()
        tasks = cerebro.core.to_do_task_list(current_user[cerebro.aclasses.Users.DATA_ID], False)
        for task in tasks:
                td = task.start() - datetime.datetime.now()
                seconds = td.total_seconds()
                if seconds >= 0 and seconds < 1800: # if the task has not started yet and it is less than 30 minutes till its start
                        message = 'The task: ' + task.name() + ' is starting in  ' + str(round(seconds/60)) + " minutes."
                        cerebro.core.notify_user(message,  task.id()) # displaying the notification

To make the logoff sample executable and see how it works it is necessary to do the following.

Rename logoff.py.template to logoff.py.

Uncomment the function call sample in the logoff.py file:

import cerebro
import examples

def logoff():
    return examples.logoff.logoff()

The module of logoff handling example is located in examples/logoff.py


# -*- coding: utf-8 -*-
This example shows a procedure of checking if a user has signed off appropriate amount of his/her today's working time on quitting Cerebro.
If it is later than 18:00 o'clock now and the user signed off less than 8 hours, we are asking if he/she is sure to quit
without appropriate amount of time signed off in his/her daily report(s).


logoff() - is called on quitting Cerebro
check_start_tasks() - is called by timer and checks the list of user's tasks

import cerebro
import datetime

def logoff():

        if datetime.datetime.now().hour >= 18: # If it is later than 18:00 o'clock now, the daily report checking starts

                database = cerebro.db.Db() # getting a database object to make a query

                # Also, we need a current user's ID to make the query
                current_user_id = cerebro.core.user_profile()[cerebro.aclasses.Users.DATA_ID] # current user's ID

                # and the period of time to search within. In this case it is today.
                start = datetime.datetime.combine(datetime.datetime.now().date(),  datetime.time(0, 0, 0))
                stop = datetime.datetime.combine(start.date(),  datetime.time(23,  59 ,  59,  999))

                # Executing a query to get the amount of hours signed off by the user in his/her today's reports
                reports = database.execute('select sum(declared) from "dumpReportsByUser"($1,$2::text::timestamp with time zone,$3::text::timestamp with time zone)', current_user_id, start.isoformat(),  stop.isoformat())

                question = ''
                if len(reports) == 0 or reports[0][0] == None: # if no reports found at all
                        question = 'You have not reported today yet.\n Are you sure you want to quit?'
                elif reports[0][0] < 8*60: # if reports found but they contain less than 8 hours all in all
                        question = 'You have signed only ' + str(round(reports[0][0]/60, 1)) + ' hours off for today.\n Are you sure you want to quit?'

                if question != '': # if a question arises
                        # displaying it to the user
                        if cerebro.gui.question_box('Cerebro',  question) == False: # if the user cancels to quit
                                return False # the session is not terminated and the user can make the daily reporting

        # Stopping the timer from calling the check_start_tasks function, previously launched on Cerebro logon (the "logon" module)

        return True