Question

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 don’t know how to use the NSManagedObject Country with CoreData as well as a normal Object.

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.