CODEWITHSUNDEEP
iosxcodecore-datansmanagedobject
RonLugge
RonLugge

Reputation: 5174

Why are my NSManagedObject subclass methods not being recognized?

I've (heavily) subclassed NSManagedObject for a project. It worked in the original project seamlessly and without any effort.

I copied those files over to a new project, manually adding the appropriate CoreData classes to the new data model.

Unfortunately, I'm having 'issues'. For some reason, the methods of the subclass in question are being ignored. The exact same code between the two projects, but I'm suddenly getting an unrecognized selector issue.

NSFetchRequest *blockRequest=[[NSFetchRequest alloc] init];
NSEntityDescription *blockDesc=[NSEntityDescription entityForName:@"AdBlock" 
                                           inManagedObjectContext:context];
[blockRequest setEntity:blockDesc];

AdBlock *curBlock=[adBlocks objectAtIndex:blockIndex];

adBlocks=[context executeFetchRequest:blockRequest error:nil];

for (AdBlock *block in adBlocks) {
    [block initAdBlock];//Crashes with unrecognized selector
}

I've checked, and the appropriate .m files got added to the compiler build phase. The code was quite literally copy&paste and is identical between the two projects -- source works, destination doesn't.

I've noticed that I don't explicitly tell the context that it should return the subclass type, but that wasn't an issue in the old project, so why should it be an issue in the new one?

Upvotes: 0

Views: 1664

Answers (3)

ssdscott
ssdscott

Reputation: 693

I know this question is stale, but maybe someone searching will find this helpful.

I've been using categories to add additional functions to NSManagedObject subclasses. This allows me to use the XCode command to generate the class definition without destroying any of the custom logic. Ron mentions this in a comment on the selected answer - just thought it would be worth calling attention to as I find it's a pretty slick solution.

Upvotes: 1

wkhatch
wkhatch

Reputation: 2741

Make sure you check your model and ensure that you've change the class names in the inspector. Otherwise, they'll return as NSManagedObjects no matter what. And use mogenerator so you don't have to worry about regenerating your classes.

Upvotes: 1

esthepiking
esthepiking

Reputation: 1647

When something like this happens to me, there's two things I try. The first thing I do is make sure I properly #imported the NSManagedObject subclass (I forget that way more often than I should), but as you said you copied and pasted, I don't think that is your problem. The second thing I try is to rebuild the NSManagedObjects by going to File>New>File then NSManagedObject Subclass then selecting the NSManagedObjects that I changed something in. I would recommend rebuilding all of them in your case. See if that works. It may not, but it's an easy place to start.

Upvotes: 1

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