Re: Changes in KVO behavior on SL?
On 2 Sep 2009, at 13:47, Kevin Brock wrote: Likewise, there's never been any guarantee that invoking - observeValueForKeyPath:ofObject:change:context: will provoke the receiver to call -valueForKeyPath: on the object whose property has changed. If the observer wants, it can rely totally on the information in the change dictionary. If you were using will/ didChange..., then KVO can be expected to invoke valueForKey: on the object whose property is changing, but that's not what (you say) you're doing. Thanks. That was helpful. On 10.5 the receiver *does* apparently always call valueForKeyPath, at least with the receivers we're talking to. Maybe they weren't checking the dictionary on 10.5, or were calling the fn if the data on the new values wasn't found in the dictionary, but are being stricter on 10.6. Ken didn't contradict the behaviour you have observed. But you are [were] relying on a mechanism that is undocumented and quite possibly accidental on the part of Apple's engineers, and so could have changed at any time, or might have been erratic/fragile even on 10.5. In other words, it is merely fortunate that your app ever worked on 10.5, and not by design ;-) The documented pattern that Ken described should work on both 10.5 and 10.6, and will always work... until deprecated anyway! ___ 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
Re: Changes in KVO behavior on SL?
On Sep 1, 2009, at 6:11 PM, Ken Thomases wrote: On Sep 1, 2009, at 7:14 PM, Kevin Brock wrote: We've got an app that is using keyValueForPath: and observeValueForKeyPath:ofObject:change:context: to keep a status window up-to-date. On 10.5 it works fine. On 10.6 keyValueForPath: is called exactly once per property. When we later create a change dictionary and send observeValueForKeyPath:ofObject:change:context: to the observer for a property, valueForKeyPath: isn't called again. Huh? You have never been supposed to call - observeValueForKeyPath:ofObject:change:context: yourself, nor construct change dictionaries. When a property changes in a way that KVO can't automatically track, you are supposed to call -will/ didChangeValueForKey: (or the corresponding will/didChange... methods for set or array mutation) and KVO will generate the change notification itself. Good to know. I'll give that a try. Lot of legacy code in that part of the app--I doubt that this is the last thing I'll run into. Likewise, there's never been any guarantee that invoking - observeValueForKeyPath:ofObject:change:context: will provoke the receiver to call -valueForKeyPath: on the object whose property has changed. If the observer wants, it can rely totally on the information in the change dictionary. If you were using will/ didChange..., then KVO can be expected to invoke valueForKey: on the object whose property is changing, but that's not what (you say) you're doing. Thanks. That was helpful. On 10.5 the receiver *does* apparently always call valueForKeyPath, at least with the receivers we're talking to. Maybe they weren't checking the dictionary on 10.5, or were calling the fn if the data on the new values wasn't found in the dictionary, but are being stricter on 10.6. Kevin ___ 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
Re: Changes in KVO behavior on SL?
On Sep 1, 2009, at 7:14 PM, Kevin Brock wrote: We've got an app that is using keyValueForPath: and observeValueForKeyPath:ofObject:change:context: to keep a status window up-to-date. On 10.5 it works fine. On 10.6 keyValueForPath: is called exactly once per property. When we later create a change dictionary and send observeValueForKeyPath:ofObject:change:context: to the observer for a property, valueForKeyPath: isn't called again. Huh? You have never been supposed to call - observeValueForKeyPath:ofObject:change:context: yourself, nor construct change dictionaries. When a property changes in a way that KVO can't automatically track, you are supposed to call -will/ didChangeValueForKey: (or the corresponding will/didChange... methods for set or array mutation) and KVO will generate the change notification itself. Likewise, there's never been any guarantee that invoking - observeValueForKeyPath:ofObject:change:context: will provoke the receiver to call -valueForKeyPath: on the object whose property has changed. If the observer wants, it can rely totally on the information in the change dictionary. If you were using will/ didChange..., then KVO can be expected to invoke valueForKey: on the object whose property is changing, but that's not what (you say) you're doing. 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: http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
Re: Changes in KVO behavior on SL?
On Tue, Sep 1, 2009 at 5:14 PM, Kevin Brock wrote: > We've got an app that is using keyValueForPath: and > observeValueForKeyPath:ofObject:change:context: to keep a status window > up-to-date. It's valueForKeyPath:. > On 10.5 it works fine. On 10.6 keyValueForPath: is called exactly once per > property. When we later create a change dictionary and send > observeValueForKeyPath:ofObject:change:context: to the observer for a > property, valueForKeyPath: isn't called again. You need to post your code. > Is there a known change in 10.6 to how these functions are supposed to work? > It's really odd, because all of our low-level code, including some KEXTs, > works fine in 32 bit SL, but this one piece doesn't... There are changes -- read the release notes. None of them should introduce the behavior you're seeing. --Kyle Sluder ___ 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
Changes in KVO behavior on SL?
We've got an app that is using keyValueForPath: and observeValueForKeyPath:ofObject:change:context: to keep a status window up-to-date. On 10.5 it works fine. On 10.6 keyValueForPath: is called exactly once per property. When we later create a change dictionary and send observeValueForKeyPath:ofObject:change:context: to the observer for a property, valueForKeyPath: isn't called again. Is there a known change in 10.6 to how these functions are supposed to work? It's really odd, because all of our low-level code, including some KEXTs, works fine in 32 bit SL, but this one piece doesn't... Kevin ___ 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
