On Feb 16, 2012, at 12:45 PM, Greg Parker wrote: > On Feb 16, 2012, at 12:42 PM, Matt Neuburg <m...@tidbits.com> wrote: >> On Feb 16, 2012, at 12:05 PM, Greg Parker wrote: >>> >>> The question is, who retains the observer? The __block __weak variable does >>> not, because it's weak. NSNotificationCenter does not, as I understand it. >> >> It does, actually; thanks for pressing me on this point. > > The NSNotificationCenter documentation says: > "Important: The notification center does not retain its observers…"
We may be talking at cross purposes. If you register by saying addObserver:selector:name:object:, the notification center does not retain the observer object named in the first param. But if you register by saying addObserverForName:object:queue:usingBlock:, it returns an observer object, and the notification center *does* retain that observer. And, since that block will probably mention self, and since the observer effectively consists of a wrapper for that block, the observer is retaining you. Hence the cycle. You *must* unregister or you will leak yourself. The example I cited shows how to do that. m. -- matt neuburg, phd = m...@tidbits.com, http://www.apeth.net/matt/ pantes anthropoi tou eidenai oregontai phusei Programming iOS 5! http://shop.oreilly.com/product/0636920023562.do RubyFrontier! http://www.apeth.com/RubyFrontierDocs/default.html TidBITS, Mac news and reviews since 1990, http://www.tidbits.com _______________________________________________ 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: https://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
