Insert ManagedObject subclass into Context - ios

Question

I have a managed object subclass ("item") which was created as follows:
Item *item = [[item alloc] init];
item.v1 = #"value1";
item.v2 = #"value2";
item.v3 = #"value3";
So, now I have this and I would like to insert it into a managed object context. I can do this:
Item *newitem = [NSEntityDescription insertNewObjectForEntityName:#"Item" inManagedObjectContext:_context]
newitem.v1 = item.v1;
newitem.v2 = item.v2;
newitem.v3 = item.v3;
[_context save:&error]
But surely there is a better way, no? Can I not just insert item without doing a field-by-field copy?
TIA
EDIT: I'm adding some context to the question:
The point is I ALREADY HAVE an Item object that I decide to insert after it has been loaded with 20 or so fields worth of data. I want to be able to insert it as a managed object. I don't want to insert the managed object until AFTER the Item object has been loaded up.
Geez. Not sure what's with the downvotes. Apparently my question wasn't worded well, I don't know.

Answer 1

Taking one single look in Apple CoreData documentation will show you that you don't need the first block of code. Just do like follows:
Item *newitem = [NSEntityDescription insertNewObjectForEntityName:#"Item" inManagedObjectContext:_context]
newitem.v1 = #"value1";
newitem.v2 = #"value2";
newitem.v3 = #"value3";
[_context save:&error]
That is it. If you not have done so far, start learning the above documentation by heart. Otherwise you will face many disasters with CoreData!

Answer 2

The problem with your first block of code, is that it is not the normal way of creating an NSManagedObject. You need to give it an EntityDescription in order to later insert it into an NSManagedObjectContext.
If you for some reason need to create temporary NSManagedObject that you do not wish to insert, you can do it by passing nil for the context parameter:
NSEntityDescription *entity = [NSEntityDescription entityForName:#"MyEntity" inManagedObjectContext:myMOC];
NSManagedObject *unassociatedObject = [[NSManagedObject alloc] initWithEntity:entity insertIntoManagedObjectContext:nil];
When you later decide that you want to insert the object, you can just have the context inserting it:
[context insertObject:unassociatedObject];
[context save:&error];