perform segue after webservice

Question

Hi I am failry new to iOS development and wanted to know if there is a equivalent of asynctask in iOS? I want my web service to finish and then I want to pass the contents of my web service to nextview controller

@IBAction func searchAction(_ sender: Any) {

    let airportName: String = airportCode.text!
    let minutesBefore: String = minutesBehind.text!
    let minutesAfter: String = minutesAhead.text!

    //web service request

    self.data = FlightWebService().getFlightData(airportCode: airportName, minutesBehind: minutesBefore, minutesAhead: minutesAfter)
    print(self.data)


    //how to pass data to the next view controller
    performSegue(withIdentifier: "goToSearch", sender: self)
}

Answer 1

You Can use URLSession available from ios 7.0 and later.

In your method you can run async task

func searchAction() {
    let defaultSessionConfiguration = URLSessionConfiguration.default
    let defaultSession = URLSession(configuration: defaultSessionConfiguration)

    let url = URL(string: "typeHereYourURL")
    var urlRequest = URLRequest(url: url!)

    let params = ""// json or something else
    let data = params.data(using: .utf8)

    urlRequest.httpMethod = "POST"
    urlRequest.httpBody = data

    let dataTask = defaultSession.dataTask(with: urlRequest) { (data, response, error) in
        performSegue(withIdentifier: "YourVCIdentifier", sender: self)
    }

    dataTask.resume()
}

or you can create serial queue and run FlightWebService request in another thread

func searchAction() {
    let newQueue = DispatchQueue(label: "queue_label")
    newQueue.async {
        self.data = FlightWebService().getFlightData(airportCode: airportName, minutesBehind: minutesBefore, minutesAhead: minutesAfter)
        print(self.data)

        DispatchQueue.main.async {
            performSegue(withIdentifier: "YourVCIdentifier", sender: self)
        }
    }
}

and override this to send parameters to the next ViewController

override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
    if segue.identifier == "YourVCIdentifier" {
        if let destinationVC = segue.destination as? YourVC {
            destinationVC.exampleStringProperty = //send data here recived earlier
        }
    }
}