On Apr 20, 2017, at 10:24 , Charles Srstka <cocoa...@charlessoft.com> wrote: > > I mean, yes, we could go all the way down to explaining how everything works > in terms of the physics and chemistry of electrons and semiconductors, but > that wouldn’t be very practical, would it?
I subscribe to the principle already quoted from the documentation: If you KVO-observe a property, mark it “dynamic”. I like this because it is simple and unambiguous. If anyone asked me for advice, I’d say to follow this principle and don’t agonize any further. As a different discussion, at a different level, I agree that there are scenarios where you can omit “dynamic” and still get all the KVO notifications you wanted. What scenarios? Well, I think the essence of your argument is that it can be omitted for a KVO-observed *dependent* property. That at least sounds pretty plausible to me, and it may even be true by definition. If anyone asked you for advice, then I guess you’d say to accept this as an extension of the documented principle. Me, I’m not 100% certain about this, if for no other reason than the documented principle is future-proof against a change in the way things work where Apple says, “Well, we told to you mark all KVO-observed properties dynamic.” But, people can go for advice where they want. Where I disagree is in your much stronger claim that a computed property is *necessarily* a dependent property. I think this is just false. The Swift distinction between computed and stored properties is syntactic and has nothing to do with KVO**. A KVO-observed computed property should therefore, according to the documented principle, be marked “dynamic”. For anyone following your extended principle, if it’s also a dependent property, they can omit the “dynamic”. If not, not. ** Indeed, it’s trivially easy to convert a public stored property into a public computed property that uses a private, stored, non-KVO-observed property as its instance storage. _______________________________________________ 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
