Subscribing to Notifications

Consider the following class:

MyClass = Class.create(common.InterfaceImplementation /* …or a subclass thereof */,
{
    initialize : function($super) {
        $super();
        // …do things
    }
});
  

Making this class respond to Notifications is easy. Here, the class is notified when a message is received within a chat:

MyClass = Class.create(common.InterfaceImplementation /* …or a subclass thereof */,
{
    initialize : function($super) {
        $super();
 
        // Before registering as an observer, this object must declare
        // that it implements the appropriate observer interface.
        this.addImplementedInterface(webservices.Interfaces.IReceivedTextNotificationObserver, webservices);
 
        // Register as an observer, and begin receiving Notifications.
        webservices.NotificationRegistry.registerObserver(this, webservices.Interfaces.IReceivedTextNotificationObserver);
    },
 
    // Fulfill the implementation contract of the
    // IReceivedTextNotificationObserver interface.
    processReceivedTextNotification : function(notification) {
        var text = notification.get_messageText();
        var sender = notification.get_participantId();
        var timestamp = notification.get_dateTime();
        // Do something with these…
    }
});
  

A single object can observe any number of Notification types, and a Notification type can be observed by any number of objects.