CoreData Stack für iOS 9 und iOS 10 in Swift

Question

Ich versuche Core Data zu meinem bestehenden Projekt hinzuzufügen, das iOS 9+ unterstützt.

Ich habe Code von Xcode erzeugt habe:

// MARK: - Core Data stack 

    lazy var persistentContainer: NSPersistentContainer = { 

     let container = NSPersistentContainer(name: "tempProjectForCoreData") 
     container.loadPersistentStores(completionHandler: { (storeDescription, error) in 
      if let error = error as NSError? { 

       fatalError("Unresolved error \(error), \(error.userInfo)") 
      } 
     }) 
     return container 
    }() 

    // MARK: - Core Data Saving support 

    func saveContext() { 
     let context = persistentContainer.viewContext 
     if context.hasChanges { 
      do { 
       try context.save() 
      } catch { 
       let nserror = error as NSError 
       fatalError("Unresolved error \(nserror), \(nserror.userInfo)") 
      } 
     } 
    } 

Nach dem Erzeugen Standard Coredata-Stack in Xcode fand ich heraus, dass die neue Klasse von NSPersistentContainer von iOS verfügbar ist 10 und als Ergebnis bekomme ich einen Fehler.

Wie sollte Coredata Stack so aussehen, um sowohl iOS 9 als auch 10 zu unterstützen?

Answer 1

Hier ist der Core Data Stack, der für mich arbeitete. Ich dachte, dass, um iOS 10 zu unterstützen, ich NSPersistentContainer Klasse implementieren muss, aber ich fand heraus, dass die ältere Version mit NSPersistentStoreCoordinator auch funktioniert.

Sie müssen den Namen für Ihr Modell (coreDataTemplate) und Projekt (SingleViewCoreData) ändern.

Swift 3:

// MARK: - CoreData Stack 

    lazy var applicationDocumentsDirectory: URL = { 
     // The directory the application uses to store the Core Data store file. This code uses a directory named "com.cadiridris.coreDataTemplate" in the application's documents Application Support directory. 
     let urls = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask) 
     return urls[urls.count-1] 
    }() 

    lazy var managedObjectModel: NSManagedObjectModel = { 
     // The managed object model for the application. This property is not optional. It is a fatal error for the application not to be able to find and load its model. 
     let modelURL = Bundle.main.url(forResource: "coreDataTemplate", withExtension: "momd")! 
     return NSManagedObjectModel(contentsOf: modelURL)! 
    }() 

    lazy var persistentStoreCoordinator: NSPersistentStoreCoordinator = { 
     // The persistent store coordinator for the application. This implementation creates and returns a coordinator, having added the store for the application to it. This property is optional since there are legitimate error conditions that could cause the creation of the store to fail. 
     // Create the coordinator and store 
     let coordinator = NSPersistentStoreCoordinator(managedObjectModel: self.managedObjectModel) 
     let url = self.applicationDocumentsDirectory.appendingPathComponent("SingleViewCoreData.sqlite") 
     var failureReason = "There was an error creating or loading the application's saved data." 
     do { 
      try coordinator.addPersistentStore(ofType: NSSQLiteStoreType, configurationName: nil, at: url, options: nil) 
     } catch { 
      // Report any error we got. 
      var dict = [String: AnyObject]() 
      dict[NSLocalizedDescriptionKey] = "Failed to initialize the application's saved data" as AnyObject? 
      dict[NSLocalizedFailureReasonErrorKey] = failureReason as AnyObject? 

      dict[NSUnderlyingErrorKey] = error as NSError 
      let wrappedError = NSError(domain: "YOUR_ERROR_DOMAIN", code: 9999, userInfo: dict) 
      // Replace this with code to handle the error appropriately. 
      // abort() causes the application to generate a crash log and terminate. You should not use this function in a shipping application, although it may be useful during development. 
      NSLog("Unresolved error \(wrappedError), \(wrappedError.userInfo)") 
      abort() 
     } 

     return coordinator 
    }() 

    lazy var managedObjectContext: NSManagedObjectContext = { 
     // Returns the managed object context for the application (which is already bound to the persistent store coordinator for the application.) This property is optional since there are legitimate error conditions that could cause the creation of the context to fail. 
     let coordinator = self.persistentStoreCoordinator 
     var managedObjectContext = NSManagedObjectContext(concurrencyType: .mainQueueConcurrencyType) 
     managedObjectContext.persistentStoreCoordinator = coordinator 
     managedObjectContext.mergePolicy = NSMergeByPropertyObjectTrumpMergePolicy 
     return managedObjectContext 
    }() 

    // MARK: - Core Data Saving support 

    func saveContext() { 
     if managedObjectContext.hasChanges { 
      do { 
       try managedObjectContext.save() 
      } catch { 
       // Replace this implementation with code to handle the error appropriately. 
       // abort() causes the application to generate a crash log and terminate. You should not use this function in a shipping application, although it may be useful during development. 
       let nserror = error as NSError 
       NSLog("Unresolved error \(nserror), \(nserror.userInfo)") 
       abort() 
      } 
     } 
    } 

Answer 2

Verwenden Sie die nächste Struct für ios 9 und 10

dies für Kontext verwenden, um die nex und ersetzen ModelCoreData für Ihren Modellname von Coredata Storage.share. Kontext

Import Foundation Import Coredata

/// NSPersistentStoreCoordinator Erweiterung Erweiterung NSPersistentStoreCoordinator {

/// NSPersistentStoreCoordinator error types 
public enum CoordinatorError: Error { 
    /// .momd file not found 
    case modelFileNotFound 
    /// NSManagedObjectModel creation fail 
    case modelCreationError 
    /// Gettings document directory fail 
    case storePathNotFound 
} 

/// Return NSPersistentStoreCoordinator object 
static func coordinator(name: String) throws -> NSPersistentStoreCoordinator? { 

    guard let modelURL = Bundle.main.url(forResource: name, withExtension: "momd") else { 
     throw CoordinatorError.modelFileNotFound 
    } 

    guard let model = NSManagedObjectModel(contentsOf: modelURL) else { 
     throw CoordinatorError.modelCreationError 
    } 

    let coordinator = NSPersistentStoreCoordinator(managedObjectModel: model) 

    guard let documents = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).last else { 
     throw CoordinatorError.storePathNotFound 
    } 

    do { 
     let url = documents.appendingPathComponent("\(name).sqlite") 
     let options = [ NSMigratePersistentStoresAutomaticallyOption : true, 
         NSInferMappingModelAutomaticallyOption : true ] 
     try coordinator.addPersistentStore(ofType: NSSQLiteStoreType, configurationName: nil, at: url, options: options) 
    } catch { 
     throw error 
    } 

    return coordinator 
} 

}

struct Lagerung {

static var shared = Storage() 

@available(iOS 10.0, *) 
private lazy var persistentContainer: NSPersistentContainer = { 
    let container = NSPersistentContainer(name: "ModelCoreData") 
    container.loadPersistentStores { (storeDescription, error) in 
     print("CoreData: Inited \(storeDescription)") 
     guard error == nil else { 
      print("CoreData: Unresolved error \(String(describing: error))") 
      return 
     } 
    } 
    return container 
}() 

private lazy var persistentStoreCoordinator: NSPersistentStoreCoordinator? = { 
    do { 
     return try NSPersistentStoreCoordinator.coordinator(name: "ModelCoreData") 
    } catch { 
     print("CoreData: Unresolved error \(error)") 
    } 
    return nil 
}() 

private lazy var managedObjectContext: NSManagedObjectContext = { 
    let coordinator = self.persistentStoreCoordinator 
    var managedObjectContext = NSManagedObjectContext(concurrencyType: .mainQueueConcurrencyType) 
    managedObjectContext.persistentStoreCoordinator = coordinator 
    return managedObjectContext 
}() 

// MARK: Public methods 

enum SaveStatus { 
    case saved, rolledBack, hasNoChanges 
} 

var context: NSManagedObjectContext { 
    mutating get { 
     if #available(iOS 10.0, *) { 
      return persistentContainer.viewContext 
     } else { 
      return managedObjectContext 
     } 
    } 
} 

mutating func save() -> SaveStatus { 
    if context.hasChanges { 
     do { 
      try context.save() 
      return .saved 
     } catch { 
      context.rollback() 
      return .rolledBack 
     } 
    } 
    return .hasNoChanges 
} 
func deleteAllData(entity: String) 
{ 
    // let appDelegate = UIApplication.sharedApplication().delegate as! AppDelegate 
    let managedContext = Storage.shared.context 
    let fetchRequest = NSFetchRequest<NSFetchRequestResult>(entityName: entity) 
    fetchRequest.returnsObjectsAsFaults = false 

    do 
    { 
     let results = try managedContext.fetch(fetchRequest) 
     for managedObject in results 
     { 
      let managedObjectData:NSManagedObject = managedObject as! NSManagedObject 
      managedContext.delete(managedObjectData) 
     } 
    } catch let error as NSError { 
     print("Detele all data in \(entity) error : \(error) \(error.userInfo)") 
    } 
} 

}