NSManagedObjectContext does not work in Swift

Question

@IBAction func btnSave(sender: AnyObject) {

    let appDel: AppDelegate = UIApplication.sharedApplication().delegate as AppDelegate
    let context: NSManagedObjectContext = appDel.managedObjectContext    
}

This does not work since it says it is not unwrapped.

This is not an Xcode question. – Lorenzo B Sep 14 '14 at 16:25 — Lorenzo B, Sep 14 '14 at 16:25

score 0 · Accepted Answer · edited Sep 14 '14 at 16:23

0

Because managedObjectContext in application delegate is optional you should unwrap it with an exclamation mark change your code to this:

let context: NSManagedObjectContext = appDel.managedObjectContext!

edited Sep 14 '14 at 16:23

Lorenzo B

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answered Sep 14 '14 at 04:25

fatal error: unexpectedly found nil while unwrapping an Optional value – Henry OM Sep 14 '14 at 04:43

score 0 · Answer 2 · answered Sep 16 '14 at 18:06

You need to unwrap it, and then continue in a safe way with an if statement like so.

@IBAction func btnSave(sender: AnyObject) {
    if let context:NSManagedObjectContext = appDel.managedObjectContext! as NSManagedObjectContext {
        // safe to use the context here
    }    
}

score 0 · Answer 3 · answered Nov 29 '15 at 23:27

Did you change in AppDelegate madelURL ?

lazy var managedObjectModel: NSManagedObjectModel = {
    let modelURL = NSBundle.mainBundle().URLForResource("**YOURPROJECTNAME**", withExtension: "momd")!
    return NSManagedObjectModel(contentsOfURL: modelURL)!
}()

NSManagedObjectContext does not work in Swift

3 Answers3