libutilitaspy.patterns.observer

This module implements the base classes of the observer pattern [GoF94].

[GoF94]
  1. Gamma, R. Helm, R. Johnson and J. Vlissides. Design Patterns: Elements of reusable Object-Oriented Software. 1994
class libutilitaspy.patterns.observer.Observer[source]

An observer (also called listener) is any object which can be registered with some Observable object to be notified whenever the Observable object is updated.

notify(*args, **kwargs)[source]

Method executed whenever any Observable where self is registered is updated. It should be overriden by a subclass.

class libutilitaspy.patterns.observer.Observable[source]

An observable object is any object that has a list of registered Observer objects which are notified whenever the observable object is updated (a relevant change of state occurs).

register(observer)[source]

Registers the observer object.

Parameters:observer (Observer) – The object to register.
Post :after(self.observers) == before(self.observers) + [observer]
deregister(observer)[source]

Unregisters the observer object.

Parameters:observer (Observer) – The object to register.
Pre :observer in self.observers
Post :after(self.observers) == before(self.observers) - [observer]
update(*args, **kwargs)[source]

Notifies all registered observers.

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