This package provides two classes for working with events:
1. EventThread: A class for creating and managing events with callback routines.
This class can be used independently of TimerEvent for handling general event-driven scenarios without any time-based requirements.
2. TimerEvent: A class that extends EventThread to create timer-based events.
This class is specifically designed for scenarios where events are triggered after a certain period of time or at specific intervals.
Note: Since this class extends the EventThread class it uses most all methods defined and documented in EvenThread class.
The EventThread class creates an event that can be subscribed to and triggered with a payload. The class uses its own thread to broadcast events to subscribers. The callback function is called when the event is triggered with a payload.
The packet dictionary is passed to the callback.
The packet dictionary includes:
All parameters passed in during instantiation of the EventThread.
Minimum items included: ..
"event" = The event name
"dest" = The subscriber name provided when subscribing
"payload" = The object included in the post
"cookie" = The cookie if included when subscribing, otherwise None
The EventThread class has the following methods::
subscribe(name: str, on_event: callable): Subscribes to the event with a callback function.
unsubscribe(name: str): Unsubscribes from the event.
post(payload, **kwargs): Posts an event with a payload to the subscribers.
pause(): Pauses broadcasting events
unpause(): Unpauses the event to continue broadcasting events
stop(): Stops the event processing thread, clears the subscribers list.
Note: This can not be used as pause. Once the EventThread instance is stopped it can not be restarted.
A new instance must be created after calling stop to continue eventing, but the subscribers list will be lost.
The TimerEvent class creates a timed event that triggers at a specified interval. The class uses a Timer object to initiate the timed event. The TimerEvent class can be subscribed to using the subscribe method, which takes a name and a callback function as arguments. The callback function is executed when the timed event is triggered.
The TimerEvent class has the following methods::
subscribe(name: str, on_event: callable): Subscribes to the timed event with a callback function.
unsubscribe(name: str): Unsubscribes from the timed event.
stop(): Stops the timed event.
from timer_event import TimerEvent, EventThread
import time
# Create a TimerEvent that triggers every 5 seconds
te = TimerEvent(interval=5.0)
# Subscribe to the TimerEvent
def te_on_event(packet):
print("TimerEvent triggered")
te.subscribe(name="test_subscriber", on_event=te_on_event)
# Start the TimerEvent
te.start()
# Create an Event
event = EventThread("test_event")
# Subscribe to the Event
def ev_on_event(payload):
print(f"Event triggered with payload: {payload}")
event.subscribe(name="test_subscriber", on_event=ev_on_event)
# Post an event with a payload
event.post("test_payload")
# Sleep to allow for timer events
time.sleep(10)
# Stop the TimerEvent and Event
te.stop()
event.stop()