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CoreData Framework Reference NSMigrationManager Class Reference

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NSMigrationManager

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

Inheritance


Conforms To


Import Statement


import CoreData @import CoreData;

Availability


Available in OS X v10.5 and later.
  • 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.

    Import Statement

    import CoreData

    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.

    Import Statement

    import CoreData

    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

    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.

    Import Statement

    import CoreData

    Availability

    Available in OS X v10.7 and later.