CODEWITHSUNDEEP
ioscore-dataswift2
Manolo
Manolo

Reputation: 479

CoreData IOS9 Bug?

I am following a great book from AppCoda, it was working on IOS8 but give many errors now:

// Load menu items from database
if let managedObjectContext = (UIApplication.sharedApplication().delegate as! AppDelegate).managedObjectContext {
    let fetchRequest = NSFetchRequest(entityName: "MenuItem")
    var e: NSError?
    menuItems = managedObjectContext.executeFetchRequest(fetchRequest, error: &e) as! [MenuItem]
    if e != nil {
        println("Failed to retrieve record: \(e!.localizedDescription)")
    }
}

After Conversion to IOS9:

// Load menu items from database
if let managedObjectContext = (UIApplication.sharedApplication().delegate as! AppDelegate).managedObjectContext {
    let fetchRequest = NSFetchRequest(entityName: "MenuItem")
    let e: NSError?
    menuItems = (try! managedObjectContext.executeFetchRequest(fetchRequest)) as! [MenuItem]
    if e != nil {
        print("Failed to retrieve record: \(e!.localizedDescription)")
    }
}

So I change back "let by var" and still get a warning = Variable 'e' was never mutated; consider changing to let constant. I need var in this block, how can I get rid of this warning? Any help is more than welcome

Upvotes: 0

Views: 149

Answers (2)

Mundi
Mundi

Reputation: 80271

This is how it is done now: 

...
do { 
  let items = try context.executeFetchRequest(request)
  // do something with items
}
catch { /* react to error */ }

Upvotes: 0

Wain
Wain

Reputation: 119041

The new try means that the error isn't used, and indeed your code isn't using it really, you just define it and then check if anything happened with it, which will never be true. You should delete the error and use catch to handle problem situations.

Upvotes: 2

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