Question

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?

Answer 1

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.