On 3 Mar 2014, at 09:47, Graham Cox <graham....@bigpond.com> wrote: > > >> IAC, I don’t think it’s exactly about whether initWithCoder returns nil. >> Surely it’s about the fact that decoding a NSArray can’t deal with a nil >> element, since it can’t be inserted into the array. Simply dropping nil >> elements doesn’t even seem like a possible strategy. > > Why not? If I decode a list of objects into an array, it would be a very > simple matter when looping over those objects to skip nil items. If the code > uses -arrayWithObjects: instead, then that's a choice made by its designer, > not the only possible way to do it. I would argue that it's definitely the > wrong choice - it's making an assumption about how external code is operating. > I agree that skipping nil items seems, from our perspective, like a sound idea. However, it is seemingly not to be. It is hard to argue with the statement that you must return self from initWithCoder:.
Have you considered using: - (id)awakeAfterUsingCoder:(NSCoder *)aDecoder The docs say: If you have an advanced need that requires substituting a different object after decoding, you can do so in awakeAfterUsingCoder:. This sounds like it might offer an out. I am not sure of the detail but the docs for -awakeAfterUsingCoder allow a substitute object to be returned. Perhaps you use a single proxy object to represent all the invalid ones. Otherwise it might be possible to return NSNull +null from -initWithCoder:, though that violates the -initWithCoder: stricture to return self. When the archive is complete you can remove the proxies/NSNull instances from the collection. Given that the object doesn’t decode it would be better if it wasn’t encoded in the first place; but I imagine that is a fait accompli. 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
