Re: Question about notifying KVO observers of changes to a property.
Re: Question about notifying KVO observers of changes to a property.
- Subject: Re: Question about notifying KVO observers of changes to a property.
- From: Peter Duniho <email@hidden>
- Date: Thu, 21 May 2009 13:34:37 -0700
On May 21, 2009, at 11:33 AM, Morales Vivó Óscar wrote:
I have an cocoa controller object with a property that is actually
read from another, C++ object. It works fine when updating or
reading the value, but sometimes other C++ parts of the program will
change the value of the property and there's no good way to notify
the cocoa controller object of the change.
I wanted to know if it's an issue from, elsewhere in the program,
just call the object's willChangeValueForKey: and
didChangeValueForKey: for a property that automatically notifies
when directly changed, or if there's a more immediate and officially
sanctioned way of letting an object know that it should notify its
observers that one of its properties has changed its value.
Sorry if this is a silly question, but...
If you are able to call the associated KVO methods
(willChangeValueForKey:, didChangeValueForKey:), why can't you just
call the property setter?
I understand that if you've got data changing only within the C++,
propagating that back to the Obj-C object requires extra work. But if
you know when to call the KVO methods, surely you're already
propagating it somehow. Seems like you could at that point just use
the Obj-C object's setter instead of setting it internally to the C++
and calling the KVO methods directly.
Pete_______________________________________________
Cocoa-dev mailing list (email@hidden)
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:
This email sent to email@hidden