/**
Copies all of the attribute values from the specified object into the
current object. No class comparison is attempted here (to avoid having to
walk the inheritance tree), so care should be taken to copy values from an
object with matching keys.
*/

- (void) copyAttributesFromObject: (NSManagedObject *)managedObject {

// get the array of attribute keys and set the items accordingly
NSArray *attributeKeys = [[self entity] attributeKeys];
NSString *attributeName;

// loop through the keys
int i, count = [attributeKeys count];
for ( i=0; i<count; i++ ) {

// Get the attribute name, then copy the value
attributeName = [attributeKeys objectAtIndex: i];
[self setPrimitiveValue: [managedObject primitiveValueForKey: attributeName] forKey: attributeName];
}
}

A few suggestions:

• Make sure you’re supplying the name of the entity as specified in the .xcdatamodel file, not the name of your custom NSManagedObject subclass if you have one.
• Make sure the managed object context is not nil by the time this method is called.
• Log the context’s managedObjectModel to the console using something like NSLog(@"MOM: %@", [tempMoc managedObjectModel]);.
• Log this managed object model’s list of entities to the console, which will give you a detailed list of the entities it describes, so you can check whether your Part entity is included.

“+entityForName: could not locate an NSManagedObjectModel for entity name ‘Part’”

in the console, and doesn’t open the window. I used the following command;

Part *aPart = [NSEntityDescription insertNewObjectForEntityForName:@"Part" inManagedObjectContext:tempMoc];

with Part being the subclass of NSManagedObject. Do I need to pass the NSManagedObjectModel into my initialization method as an argument?