def remove(user: User):
if OnlineUsers.has(user):
# Remove the user from OnlineUsers list first,
# so that the server will not dispatch this event to
# the logging out user whose SocketServer
# has already shutdown.
OnlineUsers.users.remove(user)
dispatch(LogoutEvent(user), OnlineUsers.users)
else:
raise NotLoggedIn("This user has already logged out.")
def add(user: User):
if not OnlineUsers.has(user):
# The SocketServer which listens for events will start
# only after the user has SUCCESSFULLY logged in!
# Hence, the order of the following two lines of code
# DOES matter. If we reverse their order, the dispatcher
# will get a connection refused error
# (since the SocketServer has not yet started) :)
dispatch(LoginEvent(user), OnlineUsers.users)
OnlineUsers.users.append(user)
else:
raise AlreadyLoggedIn("This user has already logged in.")
def remove(exam: Exam):
if OngoingExams.has(exam):
# Stop the timer of this exam.
OngoingExams.exams[exam].timer.cancel()
# Remove the element from the dict.
del OngoingExams.exams[exam]
# Notify all users that the exam has been halt.
dispatch(HaltExamEvent(exam), OnlineUsers.users)
else:
raise NotLaunched(
"This exam has not been launched or already ended.")
def remove(self, user: User):
# Once a student left the exam, the student will not be able
# to attend the exam again, unless the exam is re-launched.
# A teacher can enter and leave as he/she wishes.
if self.has(user):
if not user.is_student:
self.teachers.remove(user)
else:
# Notify all teachers that a student has left the exam,
# and that they will not receive snapshot from that student any longer.
dispatch(LeaveExamEvent(self.exam, user), self.teachers)
else:
raise NotAttended("This user has not attended to this exam.")
def add(self, user: User):
if not self.has(user):
if user.is_student:
self.students.append(user)
# Notify all teachers that a student has attend to the exam,
# and that they should prepare for receiving snapshot from that student.
dispatch(AttendExamEvent(self.exam, user), self.teachers)
else:
self.teachers.append(user)
else:
raise AlreadyAttended(
"This user has already attended to this exam.")
def add(exam: Exam):
if not OngoingExams.has(exam):
# Create an empty student list for this exam.
OngoingExams.exams[exam] = ExamData(exam)
# Start the timer of this exam.
# Also record the start_time of timer for evaluating remaining time later.
OngoingExams.exams[exam].timer = Timer(exam.duration * 60,
OngoingExams.remove,
args=[exam])
OngoingExams.exams[exam].timer.start()
OngoingExams.exams[exam].start_time = time.time()
# Notify all users that the exam has been launched.
dispatch(LaunchExamEvent(exam), OnlineUsers.users)
else:
raise AlreadyLaunched("This exam has already been launched.")