How do i do a background network call when i get the location?

Question

When the location is changed in the background I want to update location to the server. I want a safe way to update location in the background every time I receive a significant location change. How do I make a network call?

 func endBackgroundUpdateTask() {
        UIApplication.shared.endBackgroundTask(self.backgroundUpdateTask)
        self.backgroundUpdateTask = UIBackgroundTaskInvalid
    }


    func scheduledLocationManager(_ manager: APScheduledLocationManager, didUpdateLocations locations: [CLLocation]) {
        print(locations.last?.description ?? "no location")
        self.backgroundUpdateTask = UIApplication.shared.beginBackgroundTask(expirationHandler: {
            Alamofire.request("https://testomkar.herokuapp.com/log", method: .post, parameters: ["log":locations.last?.description ?? "no location"]).validate().responseJSON(completionHandler: { (responce) in
                self.endBackgroundUpdateTask()
            })
        })


    }

Answer 1

If the application is in background state then get UIBackgroundTaskIdentifier

 func scheduledLocationManager(_ manager: APScheduledLocationManager, didUpdateLocations locations: [CLLocation]) {

    print(locations.last?.description ?? "no location")

    // Get the background identifier if the app is in background mode
    if UIApplication.shared.applicationState == .background {
       backgroundUpdateTask = UIApplication.shared.beginBackgroundTask { [weak self] in
            if let strongSelf = self {
                UIApplication.shared.endBackgroundTask(strongSelf.backgroundUpdateTask)
                self.backgroundUpdateTask = UIBackgroundTaskInvalid
            }
        }
    }

    // Call the api to update the location to your server
    Alamofire.request("https://testomkar.herokuapp.com/log", method: .post, parameters: ["log":locations.last?.description ?? "no location"]).validate().responseJSON(completionHandler: { (responce) in

           //API completion block invalidate the identifier if it is not invalid already.
           if self.backgroundUpdateTask != nil && self.backgroundUpdateTask != UIBackgroundTaskInvalid {
                 UIApplication.shared.endBackgroundTask(backgroundUpdateTask)
                 self.backgroundUpdateTask = UIBackgroundTaskInvalid
           }
     })
}