On Nov 17, 2015, at 7:18 PM, Graham Cox <graham....@bigpond.com> wrote: > > I’m using KVO to observe a bunch of properties. > > Most of these properties are split out into simple things that set a single > value, but internal to my object, some end up setting a common dictionary of > attributes, which is also a property. > > I KVO observe both the simple properties and the common dictionary property. > Mostly this is working, but when code directly sets the dictionary property, > the other properties don’t trigger their observers, even though I’m > implementing the +keyPathsForValuesAffecting<property>, which I believe > should cause the additional triggering. Have I understood that right?
If by "code directly sets the dictionary property", you mean always in a KVO-compliant manner, then yes. > @property (retain) id<NSObject> thingy; > @property (retain) NSDicitonary* dictionaryOfThings; It's not clear if this is a public or private property. If it's public, and probably even if it's private, this should be a "copy" property, not just "retain". If it's just "retain", you're not protected against somebody setting it to a mutable dictionary and then subsequently mutating the dictionary, thereby effectively mutating your property in a non-KVO-compliant manner. All of that said, I agree with Quincey. You should just use either normal properties backed by (compiler-synthesized) instance variables, or you can use a secondary object with such properties. Using a dictionary may seem like a quick-and-dirty solution, but invites problems in the long run. Regards, Ken _______________________________________________ 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
