CODEWITHSUNDEEP
swiftdictionarywatchkitdata-transfer
Stephan Beutel
Stephan Beutel

Reputation: 153

Transter custom object from Apple watch to iPhone using updateApplicationContext

I'm new to Swift and started my first app.

I'm trying to transfer data from the Apple watch to the iPhone using updateApplicationContext, but only get an error:

[WCSession updateApplicationContext:error:]_block_invoke failed due to WCErrorCodePayloadUnsupportedTypes

This is the code in my WatchKit Extension:

var transferData = [JumpData]()

func transferDataFunc() {
    let applicationDict = ["data":self.transferData]
    do {
        try self.session?.updateApplicationContext(applicationDict)
    } catch {
        print("error")
    }
}

These are the object structure I want to send:

class AltiLogObject {

let altitude : Float
let date : Date

init (altitude: Float) {
    self.altitude = altitude
    self.date = Date.init()
}

init (altitude: Float, date : Date) {
    self.altitude = altitude
    self.date = date
}

}

class JumpData {

let date : Date
let altitudes : [AltiLogObject]

init(altitudes: [AltiLogObject]) {
    self.altitudes = altitudes
    self.date = Date.init()
}
init(altitudes: [AltiLogObject], date : Date) {
    self.date = date
    self.altitudes = altitudes
}
}

To have it complete, the code of the receiver function:

private func session(session: WCSession, didReceiveApplicationContext applicationContext: [String : AnyObject]) {
    let transferData = applicationContext["data"] as! [JumpData]

    //Use this to update the UI instantaneously (otherwise, takes a little while)
    DispatchQueue.main.async() {
        self.jumpDatas += transferData
    }
}

Any hints are welcome, as I'm trying to get it running for over a week now.

Upvotes: 3

Views: 624

Answers (1)

John Pollard
John Pollard

Reputation: 450

You can only send property list values through updateApplicationContext() - the documentation states this but it isn’t clear at all.

The type of objects that you can send can be found at https://developer.apple.com/library/content/documentation/Cocoa/Conceptual/PropertyLists/AboutPropertyLists/AboutPropertyLists.html

Obviously your custom object types aren’t supported, so what you need to do is to break the properties down into the constituent parts (e.g your altitude and date properties), send them individually in the applicationContext dictionary passed into updateApplicationContext() and then reconstruct the objects on the receiving end.

It’s a real pain of course, but that’s the way this all works.

HTH

Upvotes: 3

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