errorHandler: NO with WCErrorCodeDeliveryFailed - not sure where I am going wrong

Question

I'm trying to send the UUID string of the phone to the watch once the connection is made (no action is required from the user). I've used this tutorial (https://medium.com/@vanessaforney/ios-development-watch-connectivity-32415d415854) but I keep getting "WCSession _onqueue_notifyOfMessageError:messageID:withErrorHandler:] 21FB4ABE-D177-4689-AF50-62759283112C errorHandler: NO with WCErrorCodeDeliveryFailed" error. I'm not sure what I'm doing wrong. Apologies in advance, I would have put up an MCVE/SSCCE example but I wasn't sure how it would work with this. Any help would be very appreciated!

This is the WatchSessionManager on the ios app side:

class WatchSessionManager: NSObject, WCSessionDelegate {
    static let sharedManager = WatchSessionManager()
    var device_id = ""

    private override init() {
        super.init()
        session?.delegate = self
        session?.activate()
    }

    func setDeviceID(id: String) {
        device_id = id
    }

    private let session: WCSession? = WCSession.isSupported() ? WCSession.default : nil

    private var validSession: WCSession? {
        if let session = session, session.isPaired && session.isWatchAppInstalled{
            os_log("paired and reachable")
            return session
        }
        return nil
    }


    func session(_ session: WCSession, activationDidCompleteWith activationState: WCSessionActivationState, error: Error?) {
        os_log("activationdidcompletewith")
        updateApplicationContext()
    }

    func sessionDidBecomeInactive(_ session: WCSession) {
    }

    func sessionDidDeactivate(_ session: WCSession) {
    }

    func startSession() {
        session?.delegate = self
        session?.activate()

        updateApplicationContext()
    }

    func updateApplicationContext() {
        let context = ["device_id" : device_id]
        do {
            Swift.print("trying to update application context")
            try WatchSessionManager.sharedManager.updateApplicationContext(applicationContext: context)
        } catch {
            Swift.print("error updating application context")
        }
    }
}

// Application Context
extension WatchSessionManager {
    func updateApplicationContext(applicationContext: [String : Any]) throws{
        if let session = validReachableSession {
            do {
                os_log("actually updating context")
                try session.updateApplicationContext(applicationContext)
            } catch let error {
                throw error
            }
        }
    }
}

extension WatchSessionManager {
    // Sender
    private var validReachableSession: WCSession? {
        if let session = validSession, session.isReachable {
            return session
        }
        return nil
    }

    // Receiver
    func session(session: WCSession, didReceiveMessage message: [String : Any],
                 replyHandler: ([String : Any]) -> Void, errorHandler: ((Error) -> Void)? = nil) {
        os_log("receiver")
        if message["device_id"] != nil {
            updateApplicationContext()
        }
    }
}

Then in my AppDelegate.swift, I have included:

func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {
    // Override point for customization after application launch.
    WatchSessionManager.sharedManager.startSession()
    WatchSessionManager.sharedManager.updateApplicationContext()
    return true
}

And this is my PhoneSessionManager on the watch side:

import WatchConnectivity
import os.log

class PhoneSessionManager: NSObject, WCSessionDelegate {
    func session(_ session: WCSession, activationDidCompleteWith activationState: WCSessionActivationState, error: Error?) {
        requestApplicationContext()
    }

    static let sharedManager = PhoneSessionManager()

    private let session: WCSession? = WCSession.isSupported() ? WCSession.default : nil

    func startSession() {
        session?.delegate = self
        session?.activate()
    }

    func requestApplicationContext() {
        sendMessage(message: ["device_id": true as AnyObject], replyHandler: nil, errorHandler: nil)
    }

    func sessionReachabilityDidChange(_ session: WCSession) {
        requestApplicationContext()
    }

}

extension PhoneSessionManager {
    func session(_ session: WCSession, didReceiveApplicationContext applicationContext: [String : Any]) {
        DispatchQueue.main.async(execute: {
            UserSummary.userSummary.updateFromContext(applicationContext: applicationContext)
        })
    }
}

extension PhoneSessionManager {
    private var validReachableSession: WCSession? {
        if let session = session, session.isReachable {
            return session
        }
        return nil
    }

    func sendMessage(message: [String : Any],replyHandler: (([String : Any]) -> Void)? = nil, errorHandler: ((Error) -> Void)? = nil) {
        validReachableSession?.sendMessage(message, replyHandler: replyHandler, errorHandler: errorHandler)
    }
}

Then in my ExtensionDelegate.swift I have:

import WatchKit

class ExtensionDelegate: NSObject, WKExtensionDelegate {
    override init() {
        super.init()
        PhoneSessionManager.sharedManager.startSession()
    }

    func applicationDidFinishLaunching() {
        PhoneSessionManager.sharedManager.requestApplicationContext()
        // Perform any final initialization of your application.
    }
}

Answer 1

I've had this error when trying to send an integer array using the send message function. I suggest you try sendMessage(message: ["device_id": "test"], replyHandler: nil, errorHandler: nil) instead of sending true as AnyObject. If that works for you try sending true as a boolean instead of AnyObject.