Setup a minimal NSIncrementalStore subclass for learning / experimenting with MacRuby

custom_store.rb

framework 'CoreData'

# Create a minimal model
$thing = NSEntityDescription.alloc.init
$thing.name = 'Thing'
$model = NSManagedObjectModel.alloc.init
$model.entities = [$thing]

# Create the custom store class
class CustomStore < NSIncrementalStore
  def loadMetadata(error)
    self.metadata = {NSStoreTypeKey => 'CustomStore', NSStoreUUIDKey => '0123456789ABCDEF'}
    true
  end
end

# Register the custom store class
NSPersistentStoreCoordinator.registerStoreClass(CustomStore, forStoreType:'CustomStore')

# Create the store via a PSC
$coordinator = NSPersistentStoreCoordinator.alloc.initWithManagedObjectModel($model)
$custom_store_error = Pointer.new(:object)
$custom_store = $coordinator.addPersistentStoreWithType('CustomStore', configuration:nil, URL:nil, options:nil, error:$custom_store_error)