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objective-cnsdatekvc

Setting date in core data with KVC

This has me a little mystified. For some reason I can set a date via a property, but trying to set it the same way using KVC causes an error.

I'm trying to make my code more generic, so I'd really like to be able to set my dates via KVC, given my NSManagedObject definitions as they are below. This isn't my project, and it's a very large project, so I need to work within what's already there.

I read this, but it doesn't quite address this particular issue...

Why is an NSDate in a Core Data managed Object converted to NSTimeInterval?

In the core data modeler...

NSManagedObject SomeClass   
   updateDate  Date

In code...

NSManagedObject SomeClass
   @property (nonatomic) NSTimeInterval updateDate

So in a method, I've seen code that does this when setting through the property, which works just fine, but isn't generic.

someClass.updateDate = [NSDate date] timeIntervalSinceReferenceDate

I can't do that through KVC becaus setValue: expects an ID, so it fails with this compile time error 'Sending NSTimeInterval to parameter of incompatible type 'id_Nullable'' when the same is done through KVC

[someClass setValue:[NSDate date].timeIntervalSinceReferenceDate forKey:@"updateDate"];

Suggestions for fixing this so I can use KVC to set my dates.

Thanks a lot

Solution

  • If you pass an NSNumber to setValue:forKey:, it is automatically unboxed if the property is a primitive type. So you should be able to do [someClass setValue:@([[NSDate date] timeIntervalSince1970]) forKey:@"updateDate"].