CODEWITHSUNDEEP
iosxcodedebuggingcore-dataswift
Marcus
Marcus

Reputation: 9472

Display Attributes from Core Data ManagedObjectContext

I'm learning Core Data with Swift and I want to see what is currently saved in my ManagedObjectContext. The viewDidLoad() includes println(managedObjectContext!) which outputs something like <NSManagedObjectContext: 0x1701f8500> to the console.

How do I see what the actual attributes of my LogItem are?

Thanks

Upvotes: 1

Views: 323

Answers (3)

Gandalf
Gandalf

Reputation: 2417

_NSManagedObjectContext_ manages the _NSManagedObjects_ by actually loading those objects into the memory under the same context. So if you want to display the content what your object model holds then you can access the _registeredObjects_ property of managedObjectContext. But remember that it will enlist only/all those objects which has been loaded to context.

println(managedObjectContext!.registeredObjects);

Upvotes: 3

yashwanth77
yashwanth77

Reputation: 1860

You can see a managed object context as a workbench on which you work with your model objects. You load them, you manipulate them, and save them on that workbench. Loading and saving are mediated by the persistent store coordinator. 

    let fetchRequest = NSFetchRequest(entityName: "Entity")
    if let fetchResults = managedObjectContext!.executeFetchRequest(fetchRequest, error: nil) as?       [Entity] {            
         for info in fetchResults {
         println(info.valueForKey("attribute"));
        }
     }

Upvotes: 2

Michał Ciuba
Michał Ciuba

Reputation: 7944

Managed objects are not being saved in NSManagedObjectContext. They are saved in a persistent store (like SQLite database). NSManagedObjectContext is used for loading managed objects from the persistent store into memory and making changes to them. Then you either save the changes back to the persistent store or discard them.

If you want to load managed objects (instances of an entity called YourEntity) from the persistent store into NSManagedObjectContext, use NSFetchRequest:

let fetchRequest = NSFetchRequest(entityName: "YourEntity")
if let fetchResults = managedObjectContext!.executeFetchRequest(fetchRequest, error: nil) {
    println(fetchResults);
}

If you want to see the objects that are currently loaded into NSManagedObjectContext, you can use registeredObjects method. If you want to see only updated / inserted / deleted objects, there are methods for that, called: updatedObjects, insertedObjects, deletedObjects.

Upvotes: 5

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