macOS Using NSPredicate to query a Core Data to-many relationship

[MacDonaldsd]

Hi,

I am trying to use NSPredicate to query a CoreData to-many relationship, but it errors, as it is calling it on the NSMutableSet, and not the objects themselves.

My "item" has a to-many relationship called "tags" and each tag has a name property which is an NSString.

Im trying to create an NSPredicate that sees if ANY of the Tag's name property, matches a given string.

I have tried using "ANY tags.name MATCHES[c] %@" but I get the error

[<_NSFaultingMutableSet 0x1005708f0> addObserver:forKeyPathptions:context:] is not supported. Key path: name


Any ideas are greatly appreciated, as Im a bit stuck.

Cheers

 

[Eraserhead]

Probably the %@ needs to be in quotations. i.e. the predicate should be of the form: "ANY tags.name MATCHES[c] \"%@\""

 

[MacDonaldsd]

Hi Eraserhead,

NSPredicate does the quotes for me

It seems if I do it in code using an NSFetchRequest it works, but if I set the filter predicate on a NSArrayController it fails.

 

[Eraserhead]

<shrug> I've always used quotes like that in my code.