observable

Overview ¶

Package observable is a simple generic implementation of the Observer design pattern.

Observables are identified by a string name which must be unique across an application. Calling the observable/Observe function both registers an observable by name and type, but also registers an observer by providing a notification function that is invoked when the value of the observable changes. Multiple observers can call observable/Observe to register for notifications concerning an existing observable; in this case, notification functions are called in the order in which they were registered.

To change the value of an observable, and to notify all observers by invoking their callback notification function, call the observable/Set function.