CODEWITHSUNDEEP
swiftswift2
aNaKuWaiTy
aNaKuWaiTy

Reputation: 235

Swift 2 ( executeFetchRequest ) : error handling

I got some issue with the code that I can't figure out. After I installed Xcode 7 beta and convert my swift code to Swift 2

Code:

override func viewDidAppear(animated: Bool) {

    let appDelegate: AppDelegate = UIApplication.sharedApplication().delegate as! AppDelegate

    let context: NSManagedObjectContext = AppDel.managedObjectContext
    let request = NSFetchRequest(entityName: "PlayerList")

    list = Context.executeFetchRequest(request)

    tableView.reloadData()
}

ScreenShot:

enter image description here

Upvotes: 20

Views: 16168

Answers (5)

Trevor
Trevor

Reputation: 1059

Swift 3.0 In this example PlayerList is NSManagedObject entity/class name (auto created by Xcode) 

let request: NSFetchRequest<PlayerList> = PlayerList.fetchRequest()

var result:[PlayerList]?
do{
      //Succes 
      result = try context.fetch(request)
   }catch let error as NSError {
      //Error 
      print("Error \(error)")
  }

print("result: \(result)")

Upvotes: 3

Tejveer Sambariya
Tejveer Sambariya

Reputation: 271

Try the code below

 override func viewWillAppear(animated: Bool) {

        let appDel:AppDelegate = (UIApplication.sharedApplication().delegate as! AppDelegate)
        let context = appDel.managedObjectContext
        let request = NSFetchRequest(entityName:"Users")
        do {
            let results = try context.executeFetchRequest(request)

            itemList = results as! [NSManagedObject]


        } catch let error as NSError {
            print("Could not fetch \(error), \(error.userInfo)")
        }


    }

Upvotes: 1

TotoroTotoro
TotoroTotoro

Reputation: 17622

var results = [YourEntity]?
results = try! self.managedObjectContext!.executeFetchRequest(fetchRequest) as! [YourEntity]

Upvotes: 1

Sanju
Sanju

Reputation: 1168

You could try this code: 

let  result = (try! self.manageContext.executeFetchRequest(FetchRequest)) as! [NSManageObjectClass]

Upvotes: 4

Martin R
Martin R

Reputation: 539975

As of Swift 2, Cocoa methods that produce errors are translated to Swift functions that throw an error.

Instead of an optional return value and an error parameter as in Swift 1.x:

var error : NSError?
if let result = context.executeFetchRequest(request, error: &error) {
    // success ...
    list = result
} else {
    // failure
    println("Fetch failed: \(error!.localizedDescription)")
}

in Swift 2 the method now returns a non-optional and throws an error in the error case, which must be handled with try-catch:

do {
    list = try context.executeFetchRequest(request)
    // success ...
} catch let error as NSError {
    // failure
    print("Fetch failed: \(error.localizedDescription)")
}

For more information, see "Error Handling" in "Adopting Cocoa Design Patterns" in the "Using Swift with Cocoa and Objective-C" documentation.

Upvotes: 54

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