WCSession.sendMessage works 50/50

Question

Lately, I am working on a project is related to Watch/iPhone communication again. But my code works sometimes and doesn’t work sometimes which is kind of weird to me because I think the code should either work or not. It cannot be 50/50. Therefore, I have no idea what goes wrong.

setup WCSession on iPhone:

class WatchCommunicationController: NSObject, WCSessionDelegate {

    var session : WCSession?

    override init(){

        //  super class init
        super.init()

        //  if WCSession is supported
        if WCSession.isSupported() {    //  it is supported

            //  get default session
            session = WCSession.defaultSession()

            //  set delegate
            session!.delegate = self

            //  activate session
            session!.activateSession()

        } else {

            print("iPhone does not support WCSession")
        }
    }

    ... ...
}

similar WCSession setup on Watch:

class PhoneCommunicationController: NSObject, WCSessionDelegate {

    var session : WCSession?

    override init(){

        //  super class init
        super.init()

        //  if WCSession is supported
        if WCSession.isSupported() {    //  it is supported

            //  get default session
            session = WCSession.defaultSession()

            //  set delegate
            session!.delegate = self

            //  activate session
            session!.activateSession()
        } else {

            print("Watch does not support WCSession")
        }
    }

    ... ...
}

send out message on Watch:

func sendGesture(gesture : GKGesture){

//  if WCSession is reachable
if session!.reachable {     //  it is reachable

    //  create the interactive message with gesture
    let message : [String : AnyObject]
    message = [
                "Type":"Gesture",
                "Content":gesture.rawValue
              ]

    //  send message
    session!.sendMessage(message, replyHandler: nil, errorHandler: nil)
    print("Watch send gesture \(gesture)")

} else{                     //  it is not reachable

    print("WCSession is not reachable")
}

}

related enum:

enum GKGesture: Int {
    case Push = 0, Left, Right, Up, Down
}

receive message on iPhone:

func session(session: WCSession, didReceiveMessage message: [String : AnyObject]) {

        //retrieve info
        let type = message["Type"] as! String
        let content = message["Content"]

        switch type {

        case "Gesture":
            handleGesture(GKGesture(rawValue: content as! Int)!)
        default:
            print("Received message \(message) is invalid with type of \(type)")
        }

    }

    func handleGesture(gesture : GKGesture){

        print("iPhone receives gesture \(gesture)")

        var notificationName = ""

        switch gesture {

        case .Up:
            notificationName = "GestureUp"
        case .Down:
            notificationName = "GestureDown"
        case .Left:
            notificationName = "GestureLeft"
        case .Right:
            notificationName = "GestureRight"
        case .Push:
            notificationName = "GesturePush"
        }

        NSNotificationCenter.defaultCenter().postNotificationName(notificationName, object: nil)

    }

somehow I can’t debug my Watch app on Xcode, the debug session just won’t attach. I don’t know why. Therefore, I debug one-sided with just the iPhone.

sometimes I got "receives gesture” print out, and sometimes not. And the same for getting the notification.

Answer 1

I don't know if Int would be wrapped around to NSNumber while being transfer within WCSession. If it would be, then that must be why when I use Int as the base class of the enum it won't work and works when String is the base class.

Connectivity Known Issue Your app may crash when using NSNumber and NSDate objects with the WCSession API.

Workaround: Convert an NSNumber or NSDate object to a string before calling WCSession APIs. Do the opposite conversion on the receiving side.

Watch OS 2 Beta 4 release note