Save Dictionary of custom objects in Swift using UserDefaults

Question

I'm writing an app to work with contacts and trying to save information with UserDefaults but I'm getting SIGABRT. Here's my code, what I'm doing wrong?

class Contact{
var name = String()
var phone = String()

init(name: String, phone: String){
    self.name=name
    self.phone=phone
}
required init(coder decoder: NSCoder){
    self.name = (decoder.decodeObject(forKey: "name") as? String)!
    self.phone = (decoder.decodeObject(forKey: "phone") as? String)!
}
func encode(with coder: NSCoder){
    coder.encode(name, forKey: "name")
    coder.encode(phone, forKey: "phone")
}
}

Creating contact in ViewDidLoad just for test:

        let userDefaults = UserDefaults.standard
var contactDictionary = Dictionary<String, [Contact]>()

  override func viewDidLoad() {
    super.viewDidLoad()
    contactDictionary["A"] = [Contact(name: "Annabel",phone: "000")]

    let encodedData = NSKeyedArchiver.archivedData(withRootObject: contactDictionary)
    userDefaults.set(encodedData, forKey: "contactDictionary")
    userDefaults.synchronize()
    if let data = userDefaults.data(forKey: "contactDictionary"){
        print("yep")
        contactDictionary = (NSKeyedUnarchiver.unarchiveObject(with: data) as? [String : [Contact]])!
    }
    else{
        print("nope")
    }
}

You need to make your class `NSCoding` compliant and inherit from `NSObject`. Change your Contact declaration to `class Contact: NSObject, NSCoding {`. And Btw conditionally cast to force unwrap it later is pointless. `decoder.decodeObject(forKey: "name") as! String` — Leo Dabus, Dec 15 '17 at 22:37
Regarding the force unwrap, the same applies here `NSKeyedUnarchiver.unarchiveObject(with: data) as! [String : [Contact]]` — Leo Dabus, Dec 15 '17 at 22:45
Not helping, getting the same SIGABRT, and it's writing: Unrecognized selector -[Contacts.Contact replacementObjectForKeyedArchiver:] — Candis Mayer, Dec 15 '17 at 23:03
I have tested it here and it works. Edit your question and add your actual code — Leo Dabus, Dec 15 '17 at 23:03

score 2 · Accepted Answer · answered Dec 15 '17 at 23:13

You need to make your class NSCoding compliant and inherit from NSObject. Change your Contact declaration to class Contact: NSObject, NSCoding {. And Btw conditionally cast to force unwrap it later is pointless. decoder.decodeObject(forKey: "name") as! String

class Contact: NSObject, NSCoding {
    var name = String()
    var phone = String()
    init(name: String, phone: String){
        self.name=name
        self.phone=phone
    }
    required init(coder decoder: NSCoder){
        self.name = decoder.decodeObject(forKey: "name") as! String
        self.phone = decoder.decodeObject(forKey: "phone") as! String
    }
    func encode(with coder: NSCoder){
        coder.encode(name, forKey: "name")
        coder.encode(phone, forKey: "phone")
    }
}

Testing:

let contactDictionary = ["A":[Contact(name: "Annabel",phone: "000")]]

let encodedData = NSKeyedArchiver.archivedData(withRootObject: contactDictionary)
UserDefaults.standard.set(encodedData, forKey: "contactDictionary")

if let data = UserDefaults.standard.data(forKey: "contactDictionary") {
    print("yep")
    let contactDictionary2 = NSKeyedUnarchiver.unarchiveObject(with: data) as! [String : [Contact]]
}
else{
    print("nope")
}

Save Dictionary of custom objects in Swift using UserDefaults

1 Answers1