Le 15/10/2012 08:10, Daniel Galdames a écrit :

That depends on what version of Pharo you use. In Pharo 1.4 you can use SystemChangeNotifier to do something like this:

SystemChangeNotifier uniqueInstance notify: toSomeObject ofSystemChangesOfItem: #class change: #Added using: #someMethod:.

then if a new class is added to the system, SystemChangeNotifier will call #someMethod: on toSomeObject, passing an Event to #someMethod:. You can browse the code on SystemChangeNotifier to see all the notification you can use, and the package "System-Change Notification" to see the events you can receive.

In Pharo 2.0 you can do the same thing using SystemAnnouncer:

SystemAnnouncer uniqueInstance on: ClassAdded send: #someMethod: to: toSomeObject.

You can see the different announcements you can use on browsing the package "System-announcements". In this example #someMethod: will receive an announcement.

In Pharo 2.0, it could be interesting to use the weak variant of the subscription. SystemAnnouncer uniqueInstance weak on: ClassAdded send: #someMethod: to: toSomeObject. To create a weak link to it. A convenient method when you develop those things is: SystemAnnouncer uniqueInstance unsubscribe: toSomeObject. Because you usually spend time refactoring the #someMethod: above, and it helps knowing how to remove existing triggers. And a nice tool is to look at the announcements as they are produced, with SystemAnnouncer uniqueInstance open These are the tools I found usefull when tracing the system notifications. What I missed? A browser able to show who is subscribing to what. Thierry

-- Daniel Galdames

El domingo, 14 de octubre de 2012 a las 20:14, Miguel Enrique Campusano Araya escribió:

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I want to do some logic when there is a change on the system, like when a new class is loaded or when a method change. I don't want to put this logic explicit on the methods of the system who do that. I would like to know if i could subscribe to those special events (method change, new method, changes on a class and so on) so I can do what I want outside those methods. I heard about the Announcements but I don't know if Announcements could help with this problem.

Can anyone give me some highlights to do those things?

Thanks! (I'm really trying with my english, hope it's understandable)

-- Miguel Enrique Campusano Araya Estudiante de Ingeniería Civil en Computación Universidad de Chile

-- Thierry Goubier CEA list Laboratoire des Fondations des Systèmes Temps Réel Embarqués 91191 Gif sur Yvette Cedex France Phone/Fax: +33 (0) 1 69 08 32 92 / 83 95