iOS Components and Frameworks: Understanding the Advanced Features of the iOS SDK

Creating Managed Objects

Managed objects can exist only in a managed object context (NSManagedObjectContext), which is Core Data’s working area. A managed object must be either created in or fetched from the managed object context. To create a new managed object, a reference to the managed object context is needed. The managed object context is available as a property on the application delegate for projects that have been set up using Xcode’s Master Detail project template. In addition, Core Data needs to know what entity the new managed object is for. Core Data has a class called NSEntityDescription that provides information about entities. Create a new instance using NSEntityDescription’s class method:

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NSManagedObjectContext ...