Spry User Guide - Support - Adobe

Objects as region observers
To receive notifications, an object must define a method for each notification it is interested in receiving, and then
register itself as an observer on the region.
The following example shows an object being registered as an observer on a dynamic region:
...
// Create an observer object and define the methods to receive the notifications
// it wants.
myObserver = new Object;
myObserver.onPostUpdate = function(notifier, data)
{
alert("onPostUpdate called for " + data.regionID);
};
...
// Call addObserver() to register the object as an observer.
Spry.Data.Region.addObserver("employeeListRegion", myObserver);
...
// You can unregister your object so it stops recieving notifications
// with a call to removeObserver().
Spry.Data.Region.removeObserver("employeeListRegion", myObserver);
...
...
...
The first argument for each notification method is the object that is sending the notification. For region observers,
this is not the region object. The second argument is an object that contains a regionID property that identifies the
region that triggered the notification.
To stop an object from receiving notifications, the object must be removed from the list of observers with a call to
removeObserver().
Functions as region observers
Functions can also be registered as observers. The main difference between object and function observers is that an
object is only notified for the notification methods it defines, whereas a function observer is called for every type of
event notification.
The following example shows a function being registered as an observer on a dynamic region:
SPRY
User Guide
134