save and get array of custom object in user default [duplicate] - ios

Question

I try to store Array of objects in NSUserDefaults.
I have following snippets of code:
var accounts = MyAccounts()
var array:Array<MyAccounts.MyCalendar> = accounts.populateFromCalendars()
NSUserDefaults.standardUserDefaults().
setObject(array, forKey: "test_storeAccounts_array") // <- get error here
NSUserDefaults.standardUserDefaults().synchronize()
But I get Exception:
does not implement methodSignatureForSelector: -- trouble ahead
my class structure:
class MyAccounts {
/* ... */
class MyCalendar {
var title:String?
var identifier:String?
var email:String?
var calType:String?
var isActive:Bool?
var isMainAcount:Bool?
init(){}
}
}
Any ideas?

Answer 1

Make sure your class inherits from NSObject
class MyAccounts:NSObject {
/* ... */
class MyCalendar {
var title:String?
var identifier:String?
var email:String?
var calType:String?
var isActive:Bool?
var isMainAcount:Bool?
init(){}
}
}

Answer 2

I was getting this exception in Swift 3.0. In my case, my model class was not inherit from NSObject base class. just inherit my class from NSObject base class and implements NSCoding protocol (if your container array has custom objects)
class Stock: NSObject, NSCoding {
var stockName: String?
override init() {
}
//MARK: NSCoding protocol methods
func encode(with aCoder: NSCoder){
aCoder.encode(self.stockName, forKey: "name")
}
required init(coder decoder: NSCoder) {
if let name = decoder.decodeObject(forKey: "name") as? String{
self.stockName = name
}
}
func getStockDataFromDict(stockDict stockDict:[String:AnyObject]) -> Stock {
if let stockName = stockDict["name"] {
self.stockName = stockName as? String
}
return self
}
}

Answer 3

In Swift 2, I experienced similar error while using the Notification Pattern within a custom class. Note that when the same notification(Observe) is implemented in a ViewController class , it doesn't complain. Its only with the custom class, created from a Swift file without subclassing this error was thrown
class myClass : NSObject {
override init(){
super.init()
NSNotificationCenter.defaultCenter().addObserver(self, selector: Selector("functionCall:"), name: "NotificationName", object: nil)
}
//Implement function
func functionCall(notification: NSNotification) {
//Extract the object and implement the function
}
}

Answer 4

You need to convert the class into NSData first. Something like this:
var data = NSKeyedArchiver.archivedDataWithRootObject(accounts.populateFromCalendars())
var userDefaults = NSUserDefaults.standardUserDefaults();
userDefaults.setObject(data, forKey: "test_storeAccounts_array");