event¶

Module for implementing the event-driven programming paradigm.

The event module provides a means for implementing event-driven programming. This is done through the Event object.

The Event object allows data to be communicated to callback methods via the __trigger__() method. Callback methods can un/subscribe to the Event object via the unsubscribe() and subscribe() methods.

Example usage:

import os
from mcl import Event

pub = Event()
pub.subscribe(lambda data: os.sys.stdout.write(data))
pub.__trigger__('hello world')

Classes

class Event[source]¶

Class for issuing events and triggering callback functions.

__trigger__(*args, **kwargs)[source]¶

Trigger an event and issue data to the callback functions.

Parameters:	args – Arbitrary mandatory arguments to send to callback functions. *kwargs – Arbitrary keyword arguments to send to callback functions.

is_subscribed(callback)[source]¶

Return whether a callback is registered with this object.

Parameters:	callback (function) – The callback to test for registration.
Returns:	Returns `True` if the callback has been registered with this object. Returns `False` if the callback has NOT been registered with this object.
Return type:	bool

num_subscriptions()[source]¶

Return the number of registered callbacks.

Returns:	number of registered callbacks.
Return type:	int

subscribe(callback)[source]¶

Subscribe a callback to events.

Parameters:	callback (function) – The callback to execute on a event.
Returns:	Returns `True` if the callback was successfully registered. If the callback already exists in the list of callbacks, it will not be registered again and `False` will be returned.
Return type:	bool
Raises:	`TypeError` – If the input callback does not have a ‘__call__’ method, a `TypeError` is raised.

unsubscribe(callback)[source]¶

Unsubscribe a callback from events.

Parameters:	callback (function) – The callback to be removed from event notifications.
Returns:	Returns `True` if the callback was successfully removed. If the callback does not exist in the list of callbacks, it will not be removed and `False` will be returned.
Return type:	bool