Re: Uniquing data in Core Data
Re: Uniquing data in Core Data
- Subject: Re: Uniquing data in Core Data
- From: Keary Suska <email@hidden>
- Date: Wed, 14 Aug 2013 21:46:54 -0600
On Aug 14, 2013, at 6:28 PM, Rick Mann wrote:
> I have a boolean property on an Entity for which only one should ever be true. Is it really bad to implement a custom setter that loads every other instance in the MOC that's true and sets them all to false? My code is actually good about always clearing the current one before setting the new one, but when I'm debugging, I will copy data over from another device, and it can't clear the old one in this case.
I am not sure if it bad, but it sure smells funny ;-) Anyway, the issue may be more of the data approach. It is likely that the boolean attribute shouldn't belong to the entity at all--i.e. that the attribute is really for needed by some other object or process and is not a function of the entity. A cleaner approach, IMHO, is to have a holder entity whose sole attribute is a to-one relationship to your other entity. Think of it as a singleton that always exist and maintains the particular managed object. It also requires no code at all to maintain uniqueness--simply assign the relationship.
HTH,
Keary Suska
Esoteritech, Inc.
"Demystifying technology for your home or business"
_______________________________________________
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