Tabbed Application and Core Data functions in AppDelegate Swift

Question

I am a newbie in Swift and iPhone apps. Recently I created a project with Tabbed Application. As I have already finished my project, the last step was to add core data to save my info. I decided to create a new Single View Application with core data and copy its core data functions from Single View Application AppDelegate to Tabbed Application AppDelegate.

Here is the code I copied (from Single View Application to Tabbed Application, AppDelegate.swift):

    func applicationWillTerminate(application: UIApplication) {
    // Called when the application is about to terminate. Save data if appropriate. See also applicationDidEnterBackground:.
    // Saves changes in the application's managed object context before the application terminates.
    self.saveContext()
}

// MARK: - Core Data stack

lazy var applicationDocumentsDirectory: NSURL = {
    // The directory the application uses to store the Core Data store file. This code uses a directory named "com.Spookas.bandymas" in the application's documents Application Support directory.
    let urls = NSFileManager.defaultManager().URLsForDirectory(.DocumentDirectory, inDomains: .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 = NSBundle.mainBundle().URLForResource("Model", withExtension: "momd")!
    return NSManagedObjectModel(contentsOfURL: 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.URLByAppendingPathComponent("SingleViewCoreData.sqlite")
    var failureReason = "There was an error creating or loading the application's saved data."
    do {
        try coordinator.addPersistentStoreWithType(NSSQLiteStoreType, configuration: nil, URL: url, options: nil)
    } catch {
        // Report any error we got.
        var dict = [String: AnyObject]()
        dict[NSLocalizedDescriptionKey] = "Failed to initialize the application's saved data"
        dict[NSLocalizedFailureReasonErrorKey] = failureReason

        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
    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()
        }
    }
}

There are no errors in the code when I write it; however, when I start an application and do any methods that should save the data, I get this error:

2016-06-15 10:55:19.182 Taupyk![1387:32488] CoreData: Failed to load NSManagedObjectModel with URL 'file:///Users/MyMac/Library/Developer/CoreSimulator/Devices/029E41C4-9E00-474A-BBA1-410D1211D39F/data/Containers/Bundle/Application/FE7605D7-A2F3-449E-8961-F0B33FCB4D15/Taupyk!.app/Model.momd/' fatal error: unexpectedly found nil while unwrapping an Optional value

It then points into these lines of code:

    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 = NSBundle.mainBundle().URLForResource("Model", withExtension: "momd")!
    return NSManagedObjectModel(contentsOfURL: modelURL)!
}()

It says something about Thread 1: EXC_BAD_INSTRUCTION(code=EXC_1386_INVOP, subcode=0x0)

I have also copied data model from the single view app project and renamed it into "Model", yet it still throws an error

I saw there were other people like me, however, they were able to resolve the issue whereas I can not and don't understand why it is not working even though I have done the same thing

Thanks for your help in advance

Answer 1

1. Select new file to your project.

2.core Data -> Data model->click next button - >click create button.

3. your project model Add Entity and entity name.

Answer 2

You are missing the actual CoreData database.

1. Add a new file to your project
2. select CoreData
3. Select Data Model
4. Call your data model "Model" (to match your source code)

Note, you will see this in your single view project as well.