On Sat, Jun 02, 2007 at 05:59:02PM +0200, Stephen Davies wrote:
Hi,
I've been busy with hooking Squeak to Asterisk via the Asterisk FastAGI protocol. I also want to write code to talk to the Asterisk Manager Interface.
In both cases I need to write an interface to allow others to "register" to hande particular AGI call, or to "register" to hear about particular AMI events.
I suppose the method of callback will boil down to "call method #whatever on object anObject", or maybe you could register a block to be evaluated.
Now I'm sure there must be an established way to do this in Squeak and I'd like to use it. Or at least code mine in the "usual style".
There are several semi-standard ways to do this in Squeak. The simplest is the changed-update protocol, defined in Object. The relevant method categories are "updating" and "dependents access". To use it, one registers to recieve changes by calling
anObject addDependent: interestedParty.
Then interestedParty>>update: anObject will be called whenever anObject>>changed is called. There is also a changed: message if you need more fine-grained events. It is usually used with Symbols. All of the PluggableMorphs and PluggableViews use this protocol.
A newer method is the Announcements framework, used by OmniBrowser. See http://wiki.squeak.org/squeak/5734
I am sure there are more. Object has a few method categories with events in their names, none of which I recognize. There is also the class category SystemChangeNotification; this is only used by the compiler and friends to make sure Browsers are kept up to date as methods and classes change. Tweak and Croquet also have their own frameworks I believe, based on asynchronous message sends.
So could someone point me at some classes in the system that I should look at?
Thanks, Steve _______________________________________________ Beginners mailing list Beginners@lists.squeakfoundation.org http://lists.squeakfoundation.org/mailman/listinfo/beginners