NSManagedObject subclass outside of managed object as a normal object

Question

Hi all,

I have an entity object Country with country name and country code. It is a subclass of NSManagedObject and I am using it with core data model to store its value to a persistent store.

I have a place where the same Country object will used as a normal object i.e. I will use it to store some temporary country name.

For that I have initialized the Country as following

[NSManagedObject alloc] init]

Initialization successfully done, but I am not able to set any property to that object. Hence I did an exploration. In that I found that, init for the NSManagedObject is not supported as per the documentation.

I dont know how to use the NSManagedObject Country with CoreData as well as a normal Object.

If there is a possibility, please let me know the solution as I am in desperate need of this asap..

Thanks in advance.

Answer 1

2nd paragraph of the NSManagedObject class documentation's overview:

A managed object is associated with an entity description (an instance of NSEntityDescription) that provides metadata about the object (including the name of the entity that the object represents and the names of its attributes and relationships) and with a managed object context that tracks changes to the object graph. It is important that a managed object is properly configured for use with Core Data. If you instantiate a managed object directly, you must call the designated initializer (initWithEntity:insertIntoManagedObjectContext:).

From the documentation of the method:

Important: This method is the designated initializer for NSManagedObject. You should not initialize a managed object simply by sending it init.

The documentation is actually very good.

You do not want to try to use an NSManagedObject outside of a viable CoreData stack. NSManagedObjects are quite explicitly designed to work within a correctly configured Core Data environment. If you need a temporary instance, you can either create an in-memory store or create one in your regular store and just don't save the changes without deleting it first.