On Jun 23, 2016, at 08:32 , Jonathan Mitchell <li...@mugginsoft.com> wrote: > > It would seem there is some intention here according to the header: > > - (void)insertObject:(id)object atArrangedObjectIndex:(NSUInteger)index; > // inserts into the content objects and the arranged objects (as specified by > index in the arranged objects) - will raise an exception if the object does > not match all filters currently applied > > -addObject: obviously calls - insertObject: atArrangedObjectIndex: (the > exception stack trace agrees) > > The logic of this is a bit puzzling …
Why is this puzzling? Arranged objects are *necessarily* filtered objects, so a would-be-filtered-out new object has no meaningful arranged object index. You could perhaps argue that ‘addObject:’ shouldn’t use ‘insertObject:atArrangedObjectIndex:’ for exactly this reason, but since the current behavior is documented in the header it seems that the API has already picked its functional horse to run. > My workaround was to set controller.clearsFilterPredicateOnInsertion == YES > and reset the filterPredicate following -addObject: > > It might be possible to subclass NSArrayController … There’s no need to work around at all. The correct, straightforward solution is to update the content array (i.e. the unfiltered objects being managed via the array controller) directly in a KVO compliant manner, using ‘mutableArrayValueForKey:’. The way you’ve shown your setup code fragment suggests you’re thinking of the content array being “inside” the array controller. I would suggest this is the wrong conceptualization. It’s much better to think of it is an indexed collection property of your data model, with the array controller merely being a glue object between parts of the MVC design. Editorializing a bit further, if you’ll forgive me … Your problem is a good example of why IMO it’s poor practice to use array controllers in code, except where you’re absolutely forced to. NS…Controller works fine as a standard connector piece between code and IB-based objects, but when you try to use it as API within a code design, you quickly run into inscrutable or inflexible behavior. You’ll end up writing more code *around* the NS…Controller than it would take to do what it does directly. _______________________________________________ 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
