Types of notifications

Notification of a change is passed to clients using notifications. Models generate notifications when any of the following occurs:

Any client of the model can express an interest in any one or more of these occurrences.

Be prepared to provide notifications specific to a model's data when you derive a subclass of TModel. Be sure also that the notifications are sufficient for presenters to remain consistent with the underlying data.

Refer to Chapter 3, "Notification framework" for more information on notifications and interests.

Time stamps and models

You are responsible for ensuring that models track any changes (to the data they contain) that require changes in persistent storage. Models must update their time stamp even if they automatically store the data themselves. The time stamp is used by the Compound Document framework and others to track model data changes.

The Compound Document framework also uses this time stamp as an indicator to have a particular model commit its changes at some later time. The NotifyOfChange method automatically updates the time stamp.


[Contents] [Previous] [Next]
Click the icon to mail questions or corrections about this material to Taligent personnel.
Copyright©1995 Taligent,Inc. All rights reserved.

Generated with WebMaker