On May 12, 2010, at 11:04, Ken Thomases wrote: > On May 12, 2010, at 11:44 AM, Quincey Morris wrote: > >> *All* collections emit KVO notifications when their contents change, in the >> sense of objects entering or leaving the collection. Add, remove and replace >> for arrays, add and remove for sets, set and remove for dictionaries. > > Arrays and sets may (probably; I haven't checked) emit change notifications > for their "count" and "description" properties when elements are added or > removed. But they don't emit change notifications regarding the specific > elements that they contain, which is what I think Keary was getting at. In > particular, they don't emit a change notification of kind > NSKeyValueChangeInsertion, NSKeyValueChangeRemoval, or > NSKeyValueChangeReplacement.
Well, technically, they don't *emit* these notifications -- they are emitted by KVO-compliant custom accessors and/or KVO-compliant mutable array/set proxies. I have no idea whether NSMutableDictionary does literally emit (will/DidChange...) notifications for setObject:forKey:/removeObjectForKey:, or whether those methods are invisibly wrapped in KVO-compliant methods, just like ordinary object properties when they're observed. Either way, I'm not sure it matters a lot where the notifications come from. My point was that KVO notifications of kind NSKeyValueChangeInsertion, NSKeyValueChangeRemoval, or NSKeyValueChangeReplacement do happen when arrays and sets are updated KVO-compliantly, just like KVO notifications of kind NSKeyValueChangeSetting happen when ordinary object properties are updated KVO-compliantly. _______________________________________________ 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
