Swift 2: How to keep iOS and watchOS2 apps synchronized with WatchConnectivity?

Question

I made a Counting App on iOS and WatchOS, and I want apps to be synchronized. When I count on WatchOS the number on label of iOS have to be same as on WatchOS and when I count on iOS the number on label of WatchOS have to be same as one iOS. One of these two is workin, when I count on iOS the label on WatchOS is changing, that means that is working, but when I count on WatchOS the label of iOS is not changing.

Here is code:

ViewController.swift

import UIKit
import WatchConnectivity


class ViewController: UIViewController, WCSessionDelegate {

var watchSession : WCSession?

var counter: Int {
    return NSUserDefaults().integerForKey("counter")
}

@IBAction func resetButton(sender: AnyObject) {
    NSUserDefaults().removeObjectForKey("counter")
    countedLabel.text = "\(counter)"

    if let message : String = countedLabel.text {
        do {
            try watchSession?.updateApplicationContext(
                ["message" : message]
            )
        } catch let error as NSError {
            NSLog("Updating the context failed: " + error.localizedDescription)
        }
    }
}


@IBOutlet var countedLabel: UILabel!

@IBAction func countUpButton(sender: AnyObject) {
    NSUserDefaults().setInteger(counter+1, forKey: "counter")
    countedLabel.text = "\(counter)"



    if let message : String = countedLabel.text {
        do {
            try watchSession?.updateApplicationContext(
                ["message" : message]
            )
        } catch let error as NSError {
            NSLog("Updating the context failed: " + error.localizedDescription)
        }
    }
}

func session(session: WCSession, didReceiveApplicationContext applicationContext: [String : AnyObject]){
    let message : String = applicationContext["message"] as! String
    NSUserDefaults().setInteger(Int(message)!, forKey: "counted")
    countedLabel.text = ("\(message)")
}



override func viewDidLoad() {
    super.viewDidLoad()
    // Do any additional setup after loading the view, typically from a nib.

    if(WCSession.isSupported()){
        watchSession = WCSession.defaultSession()
        watchSession!.delegate = self
        watchSession!.activateSession()
    }
}

InterfaceController.swift

import WatchKit
import Foundation
import WatchConnectivity


class InterfaceController: WKInterfaceController, WCSessionDelegate {

var watchSession : WCSession?

var counted: Int {
    return NSUserDefaults().integerForKey("counted")
}


@IBAction func resetButton() {
    NSUserDefaults().removeObjectForKey("counted")
    countedLabel.setText("\(counted)")

    if let message : String = "\(counted)"  {
        do {
            try watchSession?.updateApplicationContext(
                ["message" : message]
            )
        } catch let error as NSError {
            NSLog("Updating the context failed: " + error.localizedDescription)
        }
    }
}

@IBOutlet var countedLabel: WKInterfaceLabel!

@IBAction func countUpButton() {
    NSUserDefaults().setInteger(counted+1, forKey: "counted")
    countedLabel.setText("\(counted)")

    if let message : String = "\(counted)"  {
        do {
            try watchSession?.updateApplicationContext(
                ["message" : message]
            )
    } catch let error as NSError {
            NSLog("Updating the context failed: " + error.localizedDescription)
        }
    }
}

func session(session: WCSession, didReceiveApplicationContext applicationContext: [String : AnyObject]){
    let message : String = applicationContext["message"] as! String
    NSUserDefaults().setInteger(Int(message)!, forKey: "counted")
    countedLabel.setText(message)
}

override func awakeWithContext(context: AnyObject?) {
    super.awakeWithContext(context)

    // Configure interface objects here.
}

override func willActivate() {
    // This method is called when watch view controller is about to be visible to user
    super.willActivate()

    if(WCSession.isSupported()){
        watchSession = WCSession.defaultSession()
        // Add self as a delegate of the session so we can handle messages
        watchSession!.delegate = self
        watchSession!.activateSession()
    }
}

The problem is in InterfaceController.swift in this part of code.

if let message : String = "\(counted)"  {
        do {
            try watchSession?.updateApplicationContext(
                ["message" : message]
            )
        } catch let error as NSError {
            NSLog("Updating the context failed: " + error.localizedDescription)
        }
    }

While in ViewController.swift (iOS) is working and that part of code is:

if let message : String = countedLabel.text {
        do {
            try watchSession?.updateApplicationContext(
                ["message" : message]
            )
        } catch let error as NSError {
            NSLog("Updating the context failed: " + error.localizedDescription)
        }
    }

So, what can I use on InterfaceController.swift (WatchOS) instead of this if let message : String = "\(counted)" { as I used on ViewController.swift (iOS) this if let message : String = countedLabel.text ?

For more you can check this project: Counting App (<- URL to project)

Answer 1

I found problem, I couldn't comment on answer because comment is to long so I made a new answer. The problem is in ViewController.swift instead of using

func session(session: WCSession, didReceiveApplicationContext applicationContext: [String : AnyObject]){
let message : String = applicationContext["message"] as! String
NSUserDefaults().setInteger(Int(message)!, forKey: "counted")
countedLabel.text = ("\(message)") }

it's supposed to use

func session(session: WCSession, didReceiveApplicationContext applicationContext: [String : AnyObject]){
    dispatch_async(dispatch_get_main_queue()) { [unowned self] in
        let message : String = applicationContext["message"] as! String
        NSUserDefaults().setInteger(Int(message)!, forKey: "counter")
        self.countedLabel.text = ("\(message)")
    }
}