On 9 בספט 2012, at 22:04, Ken Thomases wrote: > On Sep 9, 2012, at 4:32 AM, Motti Shneor wrote: > >> Hi everyone. This seems a novice question, but I could not find any >> high-level approach for that. >> >> Some details of my special need: I have an NSViewController subclass, that >> should observe some attribute of its representedObject. >> >> However, the representedObject may change to another, become nil etc. > > Why is that a "however"? What's the problem? Since the representedObject is > KVO-compliant, all observations _through_ that property will automatically > follow it as it changes. >
Nope. When representedObject becomes nil, I DO NOT WANT to observe anything, and I need to remove the observance from the previous representedObject, BEFORE it is set to nil on my NSViewController. If I added myself as an observer to a specific object, in the following way: [self.representedObject addObserver:self forKeyPath:@"incomingNotes" options:NSKeyValueObservingOptionNew | NSKeyValueObservingOptionOld context:nil]; than it is MY responsibility to remove myself from that object, just before losing it (e.g. as my representedObject is set to nil). Motti Shneor, Mac OS X Software Architect & Team Leader Spectrum Reflections Ltd. _______________________________________________ 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
