On Nov 19, 2010, at 12:35 PM, Laurent Daudelin <laur...@nemesys-soft.com> wrote:
> On Nov 19, 2010, at 12:16, Matt Neuburg wrote: > >> >>> Date: Fri, 19 Nov 2010 11:58:35 -0800 >>> From: Laurent Daudelin <laur...@nemesys-soft.com> >>> Subject: NSNotificationCenter not always working? >>> >>> Is there a way to debug why the same >>> "postNotificationName:object:userInfo:" would not work the second time it's >>> called? >> >> In a word - no. This is one of the worst aspects of NSNotificationCenter; I >> have complained about it many times, filed bugs, etc., and I suggest you do >> the same. In particular we need a way to ask the center what's registered >> with it, and for what. >> >> The last time I had a problem such as you describe, it turned out that my >> own code, far off in a different file, was unregistering me - so, the second >> time the notification was posted, I was no longer an observer. This was >> discovered essentially by simple reading all my code really carefully. In >> fact, by the time I figured it out, I had actually stopped using >> notifications in that project, because they were so hard to debug. >> >> I complained about this and did receive an interesting suggestion about >> breakpoints; but this is not as good as a simple ability to query the >> notification center would be. >> >> <http://www.cocoabuilder.com/archive/cocoa/157926-how-to-debug-notification-that-never-received.html> >> >> And of course a tiny misspelling in the name of a notification will get you >> too. This can be largely avoided by using a #define but people are often >> lazy about that. >> >> m. > > Thanks, Matt. I'm of course using defines for my only notification name. I'm > suspecting it's my code as well but it's fairly straightforward. I'll revise > my code and see what I can do but I was afraid that in the case of > NSNotificationCenter, there wasn't much I could do, hence my question. Maybe > will override some methods through a protocol to see if some of the steps are > working as they should. > > If anybody has any insight, suggestions are welcomed. If you suspect that you may have a situation like the one Matt described (inadvertently unregistering yourself), try adding a log statement at each place where you register and one each place you unregister. Run the app and examine the log to see if your log item for sending the notification comes between a log for registering and one for unregistering. You may also want to make sure that you're not unregistering an object as an observer for ALL notifications someplace when you only intended to unregister it for a specific notification. wp _______________________________________________ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
