I have a simple object which conforms to the NSCoding protocol.
import Foundation
class JobCategory: NSObject, NSCoding {
var id: Int
var name: String
var URLString: String
init(id: Int, name: String, URLString: String) {
self.id = id
self.name = name
self.URLString = URLString
}
// MARK: - NSCoding
required init(coder aDecoder: NSCoder) {
id = aDecoder.decodeObject(forKey: "id") as? Int ?? aDecoder.decodeInteger(forKey: "id")
name = aDecoder.decodeObject(forKey: "name") as! String
URLString = aDecoder.decodeObject(forKey: "URLString") as! String
}
func encode(with aCoder: NSCoder) {
aCoder.encode(id, forKey: "id")
aCoder.encode(name, forKey: "name")
aCoder.encode(URLString, forKey: "URLString")
}
}
I'm trying to save an instance of it in UserDefaults but it keeps failing with the following error.
Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: 'Attempt to insert non-property list object for key jobCategory'
This is the code where I'm saving in UserDefaults.
enum UserDefaultsKeys: String {
case jobCategory
}
class ViewController: UIViewController {
#IBAction func didTapSaveButton(_ sender: UIButton) {
let category = JobCategory(id: 1, name: "Test Category", URLString: "http://www.example-job.com")
let userDefaults = UserDefaults.standard
userDefaults.set(category, forKey: UserDefaultsKeys.jobCategory.rawValue)
userDefaults.synchronize()
}
}
I replaced the enum value to key with a normal string but the same error still occurs. Any idea what's causing this?
You need to create Data instance from your JobCategory model using JSONEncoder and store that Data instance in UserDefaults and later decode using JSONDecoder.
struct JobCategory: Codable {
let id: Int
let name: String
}
// To store in UserDefaults
if let encoded = try? JSONEncoder().encode(category) {
UserDefaults.standard.set(encoded, forKey: UserDefaultsKeys.jobCategory.rawValue)
}
// Retrieve from UserDefaults
if let data = UserDefaults.standard.object(forKey: UserDefaultsKeys.jobCategory.rawValue) as? Data,
let category = try? JSONDecoder().decode(JobCategory.self, from: data) {
print(category.name)
}
Old Answer
You need to create Data instance from your JobCategory instance using archivedData(withRootObject:) and store that Data instance in UserDefaults and later unarchive using unarchiveTopLevelObjectWithData(_:), So try like this.
For Storing data in UserDefaults
let category = JobCategory(id: 1, name: "Test Category", URLString: "http://www.example-job.com")
let encodedData = NSKeyedArchiver.archivedData(withRootObject: category, requiringSecureCoding: false)
let userDefaults = UserDefaults.standard
userDefaults.set(encodedData, forKey: UserDefaultsKeys.jobCategory.rawValue)
For retrieving data from UserDefaults
let decoded = UserDefaults.standard.object(forKey: UserDefaultsKeys.jobCategory.rawValue) as! Data
let decodedTeams = NSKeyedUnarchiver.unarchiveTopLevelObjectWithData(decoded) as! JobCategory
print(decodedTeams.name)
Update Swift 4, Xcode 10
I have written a struct around it for easy access.
//set, get & remove User own profile in cache
struct UserProfileCache {
static let key = "userProfileCache"
static func save(_ value: Profile!) {
UserDefaults.standard.set(try? PropertyListEncoder().encode(value), forKey: key)
}
static func get() -> Profile! {
var userData: Profile!
if let data = UserDefaults.standard.value(forKey: key) as? Data {
userData = try? PropertyListDecoder().decode(Profile.self, from: data)
return userData!
} else {
return userData
}
}
static func remove() {
UserDefaults.standard.removeObject(forKey: key)
}
}
Profile is a Json encoded object.
struct Profile: Codable {
let id: Int!
let firstName: String
let dob: String!
}
Usage:
//save details in user defaults...
UserProfileCache.save(profileDetails)
Hope that helps!!!
Thanks
Swift save Codable object to UserDefault with #propertyWrapper
#propertyWrapper
struct UserDefault<T: Codable> {
let key: String
let defaultValue: T
init(_ key: String, defaultValue: T) {
self.key = key
self.defaultValue = defaultValue
}
var wrappedValue: T {
get {
if let data = UserDefaults.standard.object(forKey: key) as? Data,
let user = try? JSONDecoder().decode(T.self, from: data) {
return user
}
return defaultValue
}
set {
if let encoded = try? JSONEncoder().encode(newValue) {
UserDefaults.standard.set(encoded, forKey: key)
}
}
}
}
enum GlobalSettings {
#UserDefault("user", defaultValue: User(name:"",pass:"")) static var user: User
}
Example User model confirm Codable
struct User:Codable {
let name:String
let pass:String
}
How to use it
//Set value
GlobalSettings.user = User(name: "Ahmed", pass: "Ahmed")
//GetValue
print(GlobalSettings.user)
Save dictionary Into userdefault
let data = NSKeyedArchiver.archivedData(withRootObject: DictionaryData)
UserDefaults.standard.set(data, forKey: kUserData)
Retrieving the dictionary
let outData = UserDefaults.standard.data(forKey: kUserData)
let dict = NSKeyedUnarchiver.unarchiveObject(with: outData!) as! NSDictionary
Based on Harjot Singh answer. I've used like this:
struct AppData {
static var myObject: MyObject? {
get {
if UserDefaults.standard.object(forKey: "UserLocationKey") != nil {
if let data = UserDefaults.standard.value(forKey: "UserLocationKey") as? Data {
let myObject = try? PropertyListDecoder().decode(MyObject.self, from: data)
return myObject!
}
}
return nil
}
set {
UserDefaults.standard.set(try? PropertyListEncoder().encode(newValue), forKey: "UserLocationKey")
}
}
}
Here's a UserDefaults extension to set and get a Codable object, and keep it human-readable in the plist (User Defaults) if you open it as a plain text file:
extension Encodable {
var asDictionary: [String: Any]? {
guard let data = try? JSONEncoder().encode(self) else { return nil }
return try? JSONSerialization.jsonObject(with: data) as? [String : Any]
}
}
extension Decodable {
init?(dictionary: [String: Any]) {
guard let data = try? JSONSerialization.data(withJSONObject: dictionary) else { return nil }
guard let object = try? JSONDecoder().decode(Self.self, from: data) else { return nil }
self = object
}
}
extension UserDefaults {
func setEncodableAsDictionary<T: Encodable>(_ encodable: T, for key: String) {
self.set(encodable.asDictionary, forKey: key)
}
func getDecodableFromDictionary<T: Decodable>(for key: String) -> T? {
guard let dictionary = self.dictionary(forKey: key) else {
return nil
}
return T(dictionary: dictionary)
}
}
If you want to also support array (of codables) to and from plist array, add the following to the extension:
extension UserDefaults {
func setEncodablesAsArrayOfDictionaries<T: Encodable>(_ encodables: Array<T>, for key: String) {
let arrayOfDictionaries = encodables.map({ $0.asDictionary })
self.set(arrayOfDictionaries, forKey: key)
}
func getDecodablesFromArrayOfDictionaries<T: Decodable>(for key: String) -> [T]? {
guard let arrayOfDictionaries = self.array(forKey: key) as? [[String: Any]] else {
return nil
}
return arrayOfDictionaries.compactMap({ T(dictionary: $0) })
}
}
If you don't care about plist being human-readable, it can be simply saved as Data (will look like random string if opened as plain text):
extension UserDefaults {
func setEncodable<T: Encodable>(_ encodable: T, for key: String) throws {
let data = try PropertyListEncoder().encode(encodable)
self.set(data, forKey: key)
}
func getDecodable<T: Decodable>(for key: String) -> T? {
guard
self.object(forKey: key) != nil,
let data = self.value(forKey: key) as? Data
else {
return nil
}
let obj = try? PropertyListDecoder().decode(T.self, from: data)
return obj
}
}
(With this second approach, you don't need the Encodable and Decodable extensions from the top)
I've created a class with some vars and lets. One of these vars is a String. I store them in UserDefaults. If I want to access the string of this class over a singleton class, I will always get an optional String. I don't know why.
Here is the class of the object:
import Foundation
import SpriteKit
class BallSkinsClass: NSObject, NSCoding {
let id: Int
var name: String
var isBuyed: Bool
let ID = "id"
let NAME = "name"
let ISBUYED = "isBuyed"
init(id: Int, name: String, isBuyed: Bool) {
self.id = id
self.name = name
self.isBuyed = isBuyed
}
required init?(coder aDecoder: NSCoder) {
self.id = aDecoder.decodeInteger(forKey: ID)
self.name = String(describing: aDecoder.decodeObject(forKey: NAME))
self.isBuyed = aDecoder.decodeBool(forKey: ISBUYED)
}
#objc func encode(with aCoder: NSCoder) {
aCoder.encode(id, forKey: ID)
aCoder.encode(name, forKey: NAME)
aCoder.encode(isBuyed, forKey: ISBUYED)
}
}
To declare the skins, access, save and load I have these functions in my BallSkinsClass:
import Foundation
import SpriteKit
import GameKit
class BallSkins {
static var sharedInstance = BallSkins()
private init() {
}
let BALLSKINS = "ballSkins"
var standard: BallSkinsClass! = BallSkinsClass(id: 0, name: "Standard", isBuyed: true)
var billiard: BallSkinsClass! = BallSkinsClass(id: 1, name: "Billard", isBuyed: false)
var emoji: BallSkinsClass! = BallSkinsClass(id: 2, name: "Emojis", isBuyed: false)
func archiveBallSkins(ballSkins:[BallSkinsClass]) -> NSData {
print("archiving Skins")
let archivedBallSkins = NSKeyedArchiver.archivedData(withRootObject: ballSkins as Array)
return archivedBallSkins as NSData
}
func saveBallSkins(ballSkins:[BallSkinsClass]) {
let archivedBallSkins = archiveBallSkins(ballSkins: ballSkins)
UserDefaults.standard.set(archivedBallSkins, forKey: BALLSKINS)
print("saving Skins")
}
func retrieveBallSkins() -> [BallSkinsClass]? {
print("retrieving Skins")
if let unarchivedBallSkins = UserDefaults.standard.object(forKey: BALLSKINS) as? NSData {
return NSKeyedUnarchiver.unarchiveObject(with: unarchivedBallSkins as Data) as? [BallSkinsClass]
}
return nil
}
func loadBallSkins() {
print("loading Skins")
let archivedBallSkins = retrieveBallSkins()
for ballSkin in archivedBallSkins! {
switch ballSkin.id {
case 0 :
standard.isBuyed = ballSkin.isBuyed
case 1:
billiard.isBuyed = ballSkin.isBuyed
case 2:
emoji.isBuyed = ballSkin.isBuyed
default:
standard.isBuyed = ballSkin.isBuyed
}
}
}
}
If I want to access the name of the skin in any other scene or view I call:
ballSkins.sharedInstance.billiard.name
But this is an optional every time! I don't know why or where the error is.
I suppose it is caused by
required init?(coder aDecoder: NSCoder) {
self.id = aDecoder.decodeInteger(forKey: ID)
self.name = String(describing: aDecoder.decodeObject(forKey: NAME))
self.isBuyed = aDecoder.decodeBool(forKey: ISBUYED)
}
3rd line generates optional string because according to documentation
func decodeObject() -> Any?
and String(describing: ...) does not unwrap your value. You must unwrap all values from UserDefaults by yourself, providing defaultValue if nil is not possible
Purpose
I have a User class with a status property and I want store it into NSUserDefault which need to encode the User class first.
User class code updated version
public class User: NSObject, NSCoding {
override init() {}
var status: Status = .unKnow
required convenience public init(coder aDecoder: NSCoder) {
self.init()
self.status = aDecoder.decodeObject(forKey: "UserStatus") as? Status ?? .unKnow
}
public func encode(with aCoder: NSCoder) {
aCoder.encode(self.status, forKey: "UserStatus")
}
public func updatePersistentData() {
let userDefault = UserDefaults.standard
/// stuck at this line
let encodedData: Data = NSKeyedArchiver.archivedData(withRootObject: self)
userDefault.set(encodedData, forKey: "User")
userDefault.synchronize()
}
}
And my nested enumeration
enum Status {
/// is Login status
case isLogin(style: LoginStatus)
/// is register
case isRegister(style: RegisterStatus)
/// is fetch user info
case isGetUserInfo(style: GetUserInfoStatus)
/// nonabove
case unKnow
}
enum LoginStatus: Int {
case a
case b
case c
case d
}
enum RegisterStatus: Int {
case a
case b
case c
case d
}
enum GetUserInfoStatus: Int {
case a
case b
case c
case d
}
I found this, and understand I need to convert enum into raw value. It seems need to use a normal enum with string-style or Int-style...etc.
And I run the code, error message
HJC[2371:403228] -[_SwiftValue encodeWithCoder:]: unrecognized selector sent to instance 0x7f940e6bec30
HJC[2371:403228] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[_SwiftValue encodeWithCoder:]: unrecognized selector sent to instance 0x7f940e6bec30'
I tried to encode and decode the status since it's the only property in the class but you might need to do the same for the other properties if any was found
First i started with giving the State enum a value that i can encode
enum Status {
enum StatusValue {
case isLogin(LoginStatus)
case isRegister(RegisterStatus)
case isGetUserInfo(RegisterStatus)
case unknow
}
}
extension Status.StatusValue {
var value: Int {
switch self {
case .isLogin(let value):
return value.rawValue
case .isRegister(let value):
return value.rawValue
case .isGetUserInfo(let value):
return value.rawValue
case .unknow:
return -1
}
}
}
enum LoginStatus: Int {
case a = 0
case b
case c
case d
}
enum RegisterStatus: Int {
case a = 4
case b
case c
case d
}
enum GetUserInfoStatus: Int {
case a = 8
case b
case c
case d
}
Second I configured the User class to implement NSCoding
public class User: NSObject, NSCoding {
override init() {
status = .unknow
}
init(_ status: Status.StatusValue) {
self.status = status
}
var status: Status.StatusValue
public func encode(with aCoder: NSCoder) {
print(self.status.value)
aCoder.encode(self.status.value, forKey: "status")
}
public required convenience init(coder aDecoder: NSCoder) {
let status = aDecoder.decodeObject(forKey: "status") as? Status.StatusValue ?? .unknow
self.init(status)
}
func save() {
let savedData = NSKeyedArchiver.archivedData(withRootObject: self)
let defaults = UserDefaults.standard
defaults.set(savedData, forKey: "user")
defaults.synchronize()
}
}
Finally I tested the result through
let user1: User = User()
user1.status = .isLogin(LoginStatus.b)
user1.save()
let user2: User
let defaults = UserDefaults.standard
if let saveduser = defaults.object(forKey: "user") as? Data {
user2 = NSKeyedUnarchiver.unarchiveObject(with: saveduser) as! User
print(user2)
}
I would also suggest to read a little about it in here: NSCoding, Workaround for Swift Enum with raw type + case arguments?
I am trying to save and retrieve a custom class to UserDefaults in my macOS app. I am getting nil for newData
class countClass: NSObject, NSCoding {
var leftClickCount : Int = 0
init(leftClickCount: Int) {
self.leftClickCount = leftClickCount
super.init()
}
func encode(with coder: NSCoder) {
coder.encode(self.leftClickCount, forKey: "leftClickCount")
}
required convenience init?(coder decoder: NSCoder) {
guard let leftClickCount = decoder.decodeObject(forKey: "leftClickCount") as? Int
else {
return nil
}
self.init(
leftClickCount: leftClickCount
)
}
}
class ViewController: NSViewController {
override func viewDidLoad() {
super.viewDidLoad()
let leftC = countClass(leftClickCount: 25)
let ud = UserDefaults.standard
let archivedData = NSKeyedArchiver.archivedData(withRootObject: leftC)
ud.set(archivedData, forKey: "data")
ud.synchronize()
let tempData = ud.object(forKey: "data") as! Data
let newData = NSKeyedUnarchiver.unarchiveObject(with: tempData) as! countClass // Getting nil here
}
}
I was able to fix this problem by changing from:
decoder.decodeObject(forKey: "leftClickCount") as? Int
with:
decoder.decodeInteger(forKey: "leftClickCount")
I have a class PredicPair which inherits from NSCoding and NSObject as such:
class PredicPair: NSObject, NSCoding {
var weight : Float
var prediction : String
init(weight: Float, prediction: String) {
self.weight = weight
self.prediction = prediction
super.init()
}
func encode(with aCoder: NSCoder) {
aCoder.encode(weight, forKey: "weight")
aCoder.encode(prediction, forKey: "prediction")
}
required convenience init(coder aDecoder: NSCoder) {
let unarchivedWeight = aDecoder.decodeObject(forKey: "weight") as! Float
let unarchivedPrediction = aDecoder.decodeObject(forKey: "prediction") as! String
self.init(weight: unarchivedWeight, prediction: unarchivedPrediction)
}
class func saveToUserDefaults(pairs: [PredicPair]) {
let dataBlob = NSKeyedArchiver.archivedData(withRootObject: pairs)
UserDefaults.standard.set(dataBlob, forKey: "test")
UserDefaults.standard.synchronize()
}
class func loadFromUserDefaults() -> [PredicPair]? {
guard let decodedNSDataBlob = UserDefaults.standard.object(forKey: "test") as? NSData,
let loadedFromUserDefault = NSKeyedUnarchiver.unarchiveObject(with: decodedNSDataBlob as Data) as? [PredicPair]
else {
return nil
}
return loadedFromUserDefault
}
}
I am trying to store an array of the class in UserDefaults and retrieving it, but the latter always returns nil. Any reason why?
let predicPair1 = PredicPair(weight: 0, prediction: "there")
let predicPair2 = PredicPair(weight: 1, prediction: "hello")
let array = [predicPair1, predicPair2]
PredicPair.saveToUserDefaults(pairs: array)
if let retreivedArray = PredicPair.loadFromUserDefaults() {
print("loaded \(retreivedArray.count) players from NSUserDefaults")
} else {
print("failed")
}
I've also tried saving to a file using NSKeyedArchiver but retrieval fails as well.