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iosswiftcore-dataxcode8nsmanagedobject

NSManagedObject Validation and Subclasses

How to implement custom property validation methods for NSManagedObject subclasses in Xcode 8.0 or above? How we can create an NSManagedObject subclasses in Xcode 8.0?

Before Xcode 8.0

Xcode -> File -> New -> File -> Core Data -> NSManagedObject Subclass

Solution

  • For Xcode 8 or higher, NSManagedObject subclasses are created automatically unless you tell Xcode to not do that. With Swift you can let Xcode create a subclass, or create your own subclass and let Xcode add an extension with attribute declarations, or tell Xcode to not automatically generate anything. It's not about Swift 3.0 or 4.0, it's about Xcode.

    You choose one of these in the model editor. "Class Definition" is the default.

    Xcode managed object class generation

    Validation methods work the same as they ever did. You implement them in a managed object subclass. You can also implement them in an extension on that class.