On Dec 14, 2011, at 6:29 AM, Andre Masse wrote: > I have a superclass which has a "modified" BOOL property and a bunch of > subclasses based on it. When any property is changed, I need to set this flag > to YES. I can either write a setter for all properties and set this flag > there, or observe all properties and set the flag in -observeValueForKeyPath. > Both approach involve a lot of boilerplate coding (some subclasses have 20+ > properties). > > I thought about using -keyPathsForValuesAffectingModified: but I don't see > how I can set a flag using this.
This kind of approach is probably best unless you can base your superclass on NSManagedObject, which does this automatically. But, as you find, there is some difficulty. I would have a pseudo-flag, say "hasBeenModified", and implement +keyPathsForValuesAffectingHasBeenModified:. In -hasBeenModified simply set the flag KVO-compliantly. You mat want to check the flag to avoid unnecessary KVO calls. HTH. Keary Suska Esoteritech, Inc. "Demystifying technology for your home or business" _______________________________________________ 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
