Unrecognized selector sent to instance while archiving data (NSCoding) - ios

Question

-(void)transformObjects:(NSMutableArray*)array key:(NSString*)key
{
NSMutableArray* archiveArray = [[NSMutableArray alloc]initWithCapacity:array.count];
for (Furniture *furniture in array) {
// The error occurs on the line below
NSData *furnitureEncodedObject = [NSKeyedArchiver archivedDataWithRootObject:furniture];
[archiveArray addObject:furnitureEncodedObject];
}
NSUserDefaults *userData = [NSUserDefaults standardUserDefaults];
[userData setObject:archiveArray forKey:key];
}
Error log:
2014-03-04 10:55:27.881 AppName[10641:60b] -[Furniture encodeWithCoder:]: unrecognized selector sent to instance 0x15d43350
I have no idea why do I get "unrecognized selector sent to instance" when trying to archive an object.

Answer 1

You need to implement NSCoding protocol inside your Furniture object:
- (void)encodeWithCoder:(NSCoder *)aCoder{
[aCoder encodeObject:self.yourpoperty forKey:#"PROPERTY_KEY"];
}
-(id)initWithCoder:(NSCoder *)aDecoder{
if(self = [super init]){
self.yourpoperty = [aDecoder decodeObjectForKey:#"PROPERTY_KEY"];
}
return self;
}
Basically you specify what should be written (encoded) and read from a file (decoded). Usually for each property you want to store in a file, you make same as I did here in an example.

Answer 2

You'll need to implement NSCoding - here is an example with an object called SNStock that has two string properties, ticker and name:
import Foundation
class SNStock: NSObject, NSCoding
{
let ticker: NSString
let name: NSString
init(ticker: NSString, name: NSString)
{
self.ticker = ticker
self.name = name
}
//MARK: NSCoding
required init(coder aDecoder: NSCoder) {
self.ticker = aDecoder.decodeObjectForKey("ticker") as! NSString
self.name = aDecoder.decodeObjectForKey("name") as! NSString
}
func encodeWithCoder(aCoder: NSCoder) {
aCoder.encodeObject(ticker, forKey: "ticker")
aCoder.encodeObject(name, forKey: "name")
}
//MARK: NSObjectProtocol
override func isEqual(object: AnyObject?) -> Bool {
if let object = object as? SNStock {
return self.ticker == object.ticker &&
self.name == object.name
} else {
return false
}
}
override var hash: Int {
return ticker.hashValue
}
}

Answer 3

For Swift 4.1 (tested code)
import UIKit
import SwiftyJSON
class UserObject: NSObject, NSCoding {
var username: String? = ""
var userID: String? = ""
var user_email: String? = ""
var name: String? = ""
var age: String? = ""
var gender: String? = ""
override init() {
super.init()
}
init(dictionary: JSON) {
//User data initialize...
username = dictionary["username"].stringValue
userID = dictionary["iUserID"].stringValue
user_email = dictionary["email"].stringValue
name = dictionary["name"].stringValue
age = dictionary["age"].stringValue
gender = dictionary["gender"].stringValue
}
required public init(coder aDecoder: NSCoder) {
username = aDecoder.decodeObject(forKey: "username") as? String
userID = aDecoder.decodeObject(forKey: "iUserID") as? String
user_email = aDecoder.decodeObject(forKey: "email") as? String
name = aDecoder.decodeObject(forKey: "name") as? String
age = aDecoder.decodeObject(forKey: "age") as? String
gender = aDecoder.decodeObject(forKey: "gender") as? String
}
func encode(with aCoder: NSCoder) {
aCoder.encode(username, forKey: "username")
aCoder.encode(userID, forKey: "iUserID")
aCoder.encode(user_email, forKey: "email")
aCoder.encode(name, forKey: "name")
aCoder.encode(age, forKey: "age")
aCoder.encode(gender, forKey: "gender")
}
}
Note : NSCoding protocol is important

Answer 4

You have a custom class Furniture which you are trying to archive with NSKeyedArchiver. In order for this to work, the Furniture class needs to conform to the < NSCoding > protocol. Which means implementing the encodeWithCoder: and initWithCoder: methods.
Currently you don't implement these methods. You need to add them.

Answer 5

I think your Furniture class does not implement the NSCoding protocol.