Augment source code
When you need to modify base code, use the extensibility framework. You can extend base code by using the following concepts:
Events – Events are raised as preceding and succeeding operations around the base methods, meaning that you can run code before a base method is called and after it has completed. Dynamics AX 2012 introduced XPP events, which are also available in this release and can be subscribed to in your extensions. For more information, see Customize through extension and overlayering.
Plug-ins – Plug-ins are extension points that are defined by the base application. By using a class-factory pattern, plug-ins enable you to replace the base functionality. You can learn how to implement a plug-in in the tutorial Customize model elements through extension.
Class extensions – Class extensions enable you to augment a class by adding methods and variables to existing classes, tables, and forms. For more information, see Class extension model in X++.