Mac Developer Library

Developer

Core Data Framework Reference NSMigrationManager Class Reference

Options
Deployment Target:

On This Page
Language:

NSMigrationManager

Instances of NSMigrationManager perform a migration of data from one persistent store to another using a given mapping model.

  • A number between 0 and 1 that indicates the proportion of completeness of the migration. (read-only)

    Declaration

    Swift

    var migrationProgress: Float { get }

    Objective-C

    @property(readonly) float migrationProgress

    Special Considerations

    If a migration is not taking place, this property is 1. You can observe this value using key-value observing.

    Availability

    Available in OS X v10.5 and later.

  • The entity mapping currently being processed. (read-only)

    Declaration

    Swift

    var currentEntityMapping: NSEntityMapping { get }

    Objective-C

    @property(readonly, strong) NSEntityMapping *currentEntityMapping

    Discussion

    Each entity is processed a total of three times—instance creation, relationship creation, and validation.

    Special Considerations

    You can observe this value using key-value observing.

    Availability

    Available in OS X v10.5 and later.

  • A Boolean value that indicates whether the receiver tries to use a store specific migration manager to perform the migration.

    Declaration

    Swift

    var usesStoreSpecificMigrationManager: Bool

    Objective-C

    @property BOOL usesStoreSpecificMigrationManager

    Return Value

    YEStrue if the receiver uses a store-specific migration manager, otherwise NOfalse.

    Discussion

    YEStrue if the receiver uses a store-specific migration manager, otherwise NOfalse. The default value is YEStrue.

    A store-specific migration manager class is not guaranteed to perform any of the migration manager delegate callbacks or update values for the observable properties.

    Availability

    Available in OS X v10.7 and later.