CODEWITHSUNDEEP
swiftmkmapview
Kevin
Kevin

Reputation: 1189

Swift Add Pin Location From Input Coordinates

I am prompting the user to input latitude and longitudinal coordinates from another view controller. I am not sure how to translate these coordinates to a map, where a pin can be dropped. Below is a setup of my storyboard.

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Should I be using UserDefaults to transfer the saved coordinates or a global variable? I am not sure what is the best way to approach this.

Upvotes: 0

Views: 727

Answers (1)

Code Different
Code Different

Reputation: 93191

You pass the parameter from the first view controller to the second view controller by setting one of its properties.

Here's a step-by-step guide:

1 - In your FirstViewController, implement the UITabBarControllerDelegate protocol

class FirstViewController: UIViewController, UITabBarControllerDelegate {
    @IBOutlet weak var latitudeField: UITextField!
    @IBOutlet weak var longtitudeField: UITextField!

    var coordinates = [CLLocationCoordinate2D]()

    override func viewDidLoad() {
        super.viewDidLoad()
        self.tabBarController?.delegate = self
    }

    @IBAction func addCoordinates(_ sender: Any) {
        guard let lat = Double(latitudeField.text!), let long = Double(longtitudeField.text!) else {
            return
        }

        self.coordinates.append(CLLocationCoordinate2D(latitude: lat, longitude: long))
    }

    // This method will be called whenever you are switching tab
    // Note that the viewController can be the same view controller, i.e. FirstViewController
    func tabBarController(_ tabBarController: UITabBarController, didSelect viewController: UIViewController) {
        guard let secondViewController = viewController as? SecondViewController else {
            return
        }
        secondViewController.coordinates = self.coordinates
    }
}

2 - In your SecondViewController display a pin for the coordinate:

class SecondViewController: UIViewController, MKMapViewDelegate {
    @IBOutlet weak var mapView: MKMapView!

    var coordinates = [CLLocationCoordinate2D]() {
        didSet {
            // Update the pins
            // Since it doesn't check for which coordinates are new, it you go back to
            // the first view controller and add more coordinates, the old coordinates
            // will get a duplicate set of pins
            for (index, coordinate) in self.coordinates.enumerated() {
                let annotation = MKPointAnnotation()
                annotation.coordinate = coordinate
                annotation.title = "Location \(index)"

                mapView.addAnnotation(annotation)
            }
        }
    }

    override func viewDidLoad() {
        super.viewDidLoad()
        mapView.delegate = self
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }

    func mapView(_ mapView: MKMapView, viewFor annotation: MKAnnotation) -> MKAnnotationView? {
        let identifier = "pinAnnotation"
        var annotationView = mapView.dequeueReusableAnnotationView(withIdentifier: identifier) as? MKPinAnnotationView

        if annotationView == nil {
            annotationView = MKPinAnnotationView(annotation: annotation, reuseIdentifier: identifier)
            annotationView?.canShowCallout = true
        }

        annotationView?.annotation = annotation
        return annotationView
    }
}

Upvotes: 1

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