How to get current location on ViewDidLoad

Question

I think I finally figured out the location challenge, However, on Xcode and when debugging, location value gets update only if I click refresh button. before that I am getting 0.0 (initial value) for both lat and long

Would appreciate any feedback on this

here is my code

import UIKit
import CoreLocation


class ViewController: UIViewController,CLLocationManagerDelegate {


    @IBOutlet weak var iconView: UIImageView!
    @IBOutlet weak var currentTimeLabel: UILabel!
    @IBOutlet weak var temperatureLabel: UILabel!
    @IBOutlet weak var humadityLabel: UILabel!
    @IBOutlet weak var precipitationLabel: UILabel!
    @IBOutlet weak var summaryLabel: UILabel!
    @IBOutlet weak var refreshActivityIndicator: UIActivityIndicatorView!
    @IBOutlet weak var refreshButton: UIButton!

    private let apiKey = "#################"

    let locationManager = CLLocationManager()
    var locationLat: Double = 0
    var locationLong: Double = 0


    override func viewDidLoad() {

        super.viewDidLoad()

        getCurrentWeatherData()


        self.locationManager.requestWhenInUseAuthorization()
        self.locationManager.requestAlwaysAuthorization()
        if (CLLocationManager.locationServicesEnabled())
        {
            locationManager.delegate = self
            locationManager.desiredAccuracy = kCLLocationAccuracyNearestTenMeters
            locationManager.requestAlwaysAuthorization()
            locationManager.startUpdatingLocation()
        }

        //Print out location after viewDidLoad()
        println("on viewDidLoad Location is \(locationLat) and \(locationLong)")

        refreshActivityIndicator.hidden = true

        super.viewDidLoad()
    }

     func locationManager(manager: CLLocationManager!, didUpdateLocations locations: [AnyObject]!) {
        var locValue:CLLocationCoordinate2D = manager.location.coordinate

        locationLat = locValue.latitude
        locationLong = locValue.longitude
        }

    func getCurrentWeatherData() -> Void {

        var currentLat = locationLat
        var CurrentLon = locationLong

        //printout Location inside function
        println("inside func location is \(currentLat) and \(CurrentLon)")

        let baseURL = NSURL(string: "https://api.forecast.io/forecast/\(apiKey)/")
        let forecastURL = NSURL(string: "\(currentLat),\(CurrentLon)/", relativeToURL:baseURL!)
        let sharedSession = NSURLSession.sharedSession()
        let downloadTask : NSURLSessionDownloadTask = sharedSession.downloadTaskWithURL(forecastURL!, completionHandler: { (location :NSURL!, response: NSURLResponse!, error: NSError!) -> Void in

            if (error == nil) {
                let dataObject = NSData(contentsOfURL: location)
                let weatherDictionary: NSDictionary  = NSJSONSerialization.JSONObjectWithData(dataObject!, options: nil, error: nil) as NSDictionary
                let currentWeather = Current(weatherDictionary: weatherDictionary)

                dispatch_async(dispatch_get_main_queue(), { () -> Void in
                    self.temperatureLabel.text = "\(currentWeather.temprature)"
                    self.iconView.image = currentWeather.icon!
                    self.currentTimeLabel.text = "At \(currentWeather.currentTime!) it is"
                    self.humadityLabel.text = "\(currentWeather.humadity)"
                    self.precipitationLabel.text = "\(currentWeather.precipProbability)"
                    self.summaryLabel.text = "\(currentWeather.summary)"

                    // stop refresh process
                    self.refreshActivityIndicator.stopAnimating()
                    self.refreshActivityIndicator.hidden = true
                    self.refreshButton.hidden = false
                })
            } else {
                let networkIssueController = UIAlertController(title: "Ooops", message: "Something went seriously wrong!...Nope, Just enable WiFi Again" , preferredStyle: .Alert)
                self.presentViewController(networkIssueController, animated: true, completion: nil)
                let okButton = UIAlertAction(title: "OK", style: .Default, handler: nil)
                networkIssueController.addAction(okButton)
                let cancelButton = UIAlertAction(title: "Cancel", style: .Cancel, handler: nil)
                networkIssueController.addAction(cancelButton)

                dispatch_async(dispatch_get_main_queue(), { () -> Void in

                    self.refreshActivityIndicator.stopAnimating()
                    self.refreshActivityIndicator.hidden = true
                    self.refreshButton.hidden = false
                })
                }
        })

        downloadTask.resume()
    }

    @IBAction func refresh() {
        refreshButton.hidden = true
        refreshActivityIndicator.hidden = false
        refreshActivityIndicator.startAnimating()
        getCurrentWeatherData()
    }
    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
}


}

here is the println console output

inside func location is 0.0 and 0.0
on viewDidLoad Location is 0.0 and 0.0
inside func location is 35.7020691 and 139.7753269

Answer 1 · 2015-03-19T16:46:03Z

March 19, 2015 4:46pm

o.k I I figured it out, here is the answer if anyone is interested, needed to add these two bad boys in viewDidLoad

        locationLat = locationManager.location.coordinate.latitude
        locationLong = locationManager.location.coordinate.longitude

Now you need to be careful with this as it might cause a runtime error since apparently it can take couple of seconds to get the location update from GPS and this might return nil. to prevent it you can add optional unwrapping and repeat the process to get a value.

As a bonus, following is also reverse geodecoder that I added to get the location based on current coordinates. Shoutout to whoever I copied it from (SO post I guess)

var location = CLLocationManager()



        CLGeocoder().reverseGeocodeLocation(location.location, completionHandler: {(placemarks, error) -> Void in

            if error != nil {
                println("Reverse geocoder failed with error" + error.localizedDescription)
                return
            }

            if placemarks.count > 0 {
                let pm = placemarks[0] as CLPlacemark

//Printing to console to check value! 
                println("\(pm.locality)")
                println("\(pm.subLocality)")

                self.locality = pm.locality as String
                if ( pm.subLocality != nil) {

                    self.subLocality = pm.subLocality as String
                }
            }
            else {
                println("Problem with the data received from geocoder")
            }
        })

Answer 2 · 2015-04-08T22:19:40Z

April 8, 2015 10:19pm

Thanks for sharing your code.

This didn't work for me. The original values for locationLat and locationLong never change from 0. And the authorization requests aren't ever triggered triggered.

   self.locationManager.requestWhenInUseAuthorization()
        self.locationManager.requestAlwaysAuthorization()
        if (CLLocationManager.locationServicesEnabled())
        {
            locationManager.delegate = self.locationManager.delegate
            locationManager.desiredAccuracy = kCLLocationAccuracyNearestTenMeters
            locationManager.requestAlwaysAuthorization()
            locationManager.startUpdatingLocation()

Also, I can't see that the locationManager() function is ever called or doing anything.

 func locationManager(manager: CLLocationManager!, didUpdateLocations locations: [AnyObject]!) {
        var locValue:CLLocationCoordinate2D = manager.location.coordinate

        locationLat = locValue.latitude
        locationLong = locValue.longitude
        }

Answer 3 · 2015-04-10T19:38:45Z

April 10, 2015 7:38pm

d

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Mohsen Lotfi

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How to get current location on ViewDidLoad

3 Answers

Mohsen Lotfi

Mohsen Lotfi

Brian Patterson

Brian Patterson

Jared Watkins

Jared Watkins

Mohsen Lotfi

Mohsen Lotfi

Mohsen Lotfi

Mohsen Lotfi