• Ti Liu Core Data For Mac Free

Creating and Saving Managed Objects After you have defined your managed object model and initialized the Core Data stack within your application, you are ready to start creating objects for data storage. Creating Managed Objects An instance implements the basic behavior required of a Core Data model object.

The NSManagedObject instance requires two elements: an entity description (an instance) and a managed object context (an instance). The entity description includes the name of the entity that the object represents and its attributes and relationships. The managed object context represents a scratch pad where you create the managed objects. The context tracks changes to and relationships between objects. As shown in this example, the NSEntityDescription class has a class method that accepts a string for the name of the entity and a reference to the NSManagedObjectContext that the NSManagedObject instance will be associated with. The example defines the returning object as an AAAEmployeeMO object. Swift.

Ti Liu Core Data For Mac Free

let employee = NSEntityDescription. InsertNewObjectForEntityForName( 'Employee', inManagedObjectContext: managedObjectContext) as! EmployeeMO Creating NSManagedObject Subclasses By default, Core Data returns NSManagedObject instances to your application. However, it is useful to define subclasses of NSManagedObject for each of the entities in your model. Speciflcally, when you create subclasses of NSManagedObject, you can define the properties that the entity can use for code completion, and you can add convenience methods to those subclasses. To create a subclass of NSManagedObject, in the Xcode Core Data model editor, select the entity, and in the Entity pane of the Data Model inspector, enter the name in the Class field.

Then create the subclass in Xcode.