> On 6 Feb 2015, at 17:34, Jens Alfke <j...@mooseyard.com> wrote: >> On Feb 6, 2015, at 6:48 AM, Jonathan Mitchell <jonat...@mugginsoft.com> >> wrote: >> >> // remove observers >> // unregister for notifications > > I have to confess I'm still not completely certain whether these are needed > under ARC. I remember reading something about at least one of these being > handled automatically, but I just skimmed through some docs now and couldn't > find anything. I tend to put these in my classes but always wonder whether I > strictly need to. I would say it is necessary. Warnings result otherwise and unremoved observers do seem to lead to instability.
> >> // set any non-weak delegates to nil (NSTableView et al) > > I think you meant "set any _weak_ delegates to nil", i.e. clear the delegate > property of any object of whom I'm the delegate. Non-weak doesn't make sense, > because if a delegate has a strong reference to self, then self can't > possibly be in its dealloc method. Sorry. I wasn’t clear enough probably. Most of my issues centre around NSViewController. Say I have an outlet to an NSTableView and the tableView.delegate = self. The tableView.delegate is not a zeroing weak ref - in the lingo of ARC it is unsafe_unretained I believe self can be deallocated leaving tableView.delegate as a dangling pointer. > > Note that this is only necessary if (a) the other object can outlive self, > and (b) the other object could still send the delegate messages in the future. > The problem is that there is, I believe, no way to accurately determine whether a or b is true in any particular instance! Recently I have resolved issues where both NSTableView and WebView were sending delegate messages and responder chain actions in situations that I hadn’t expected. A stone dead app is the result. Jonathan _______________________________________________ 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
