CODEWITHSUNDEEP
iosswiftcore-data
Annabelle Sykes
Annabelle Sykes

Reputation: 263

Downcasting Core Data error

I am using Core data, and in my AppDelegate.swift, I get the following error on this line dict[NSUnderlyingErrorKey] = error as NSError:

'ErrorType' is not convertible to 'NSError'; did you mean to use 'as!' to force downcast?

Here is the corresponding code:

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("On The Go.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
}()

Here is the screenshot of the code:

enter image description here

I did what the error suggested, but the same error existed.

Upvotes: 0

Views: 325

Answers (2)

nielsbot
nielsbot

Reputation: 16031

What if you change your catch to include a pattern match on NSError errors?

do {
} catch let e as NSError {
    // handle NSError case
} catch {
}

Since your block can now throw, you will have to change your function like this:

lazy var persistentStoreCoordinator: NSPersistentStoreCoordinator = try? { () throws in
    // your code
}

Upvotes: 2

Tim Vermeulen
Tim Vermeulen

Reputation: 12562

Try replacing catch with catch let error as NSError.

Upvotes: 0

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