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:
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
