Swift 3: MKMapView Helpers

MKMapView+Extensions.swift

import UIKit
import MapKit

extension MKMapView {

    func showLocation(at coordinate: CLLocationCoordinate2D) {
        self.removeOverlays(self.overlays)
        self.removeAnnotations(self.annotations)

        let annotation = MKPointAnnotation()
        annotation.coordinate = coordinate
        self.addAnnotation(annotation)


        self.centerCoordinate = annotation.coordinate
        let region = MKCoordinateRegion(center: annotation.coordinate, span: MKCoordinateSpan(latitudeDelta: 0.005, longitudeDelta: 0.005))
        self.setRegion(region, animated: true)
    }

    func showDirections(from sourceLocation: CLLocationCoordinate2D, to destinationLocation: CLLocationCoordinate2D) {
        self.removeOverlays(self.overlays)
        self.removeAnnotations(self.annotations)

        let sourcePlacemark = MKPlacemark(coordinate: sourceLocation, addressDictionary: nil)
        let destinationPlacemark = MKPlacemark(coordinate: destinationLocation, addressDictionary: nil)

        let sourceMapItem = MKMapItem(placemark: sourcePlacemark)
        let destinationMapItem = MKMapItem(placemark: destinationPlacemark)

        let sourceAnnotation = MKPointAnnotation()
        sourceAnnotation.title = "Your Location"

        if let location = sourcePlacemark.location {
            sourceAnnotation.coordinate = location.coordinate
        }

        let destinationAnnotation = MKPointAnnotation()
        destinationAnnotation.title = "Your Destination"

        if let location = destinationPlacemark.location {
            destinationAnnotation.coordinate = location.coordinate
        }

        self.showAnnotations([sourceAnnotation,destinationAnnotation], animated: true )

        let directionRequest = MKDirectionsRequest()
        directionRequest.source = sourceMapItem
        directionRequest.destination = destinationMapItem
        directionRequest.transportType = .walking

        let directions = MKDirections(request: directionRequest)

        directions.calculate {
            (response, error) -> Void in

            guard let response = response else {
                if let error = error {
                    print("Error: \(error)")
                }
                return
            }

            let route = response.routes[0]
            self.add((route.polyline), level: MKOverlayLevel.aboveRoads)

            let rect = route.polyline.boundingMapRect
            var region = MKCoordinateRegionForMapRect(rect)
            region.span = MKCoordinateSpanMake(0.005, 0.005)
            
            self.setRegion(region, animated: true)
        }
    }

}

extension MainViewController: MKMapViewDelegate {
    func mapView(_ mapView: MKMapView, rendererFor overlay: MKOverlay) -> MKOverlayRenderer {
        let renderer = MKPolylineRenderer(overlay: overlay)
        renderer.strokeColor = UIColor.blue
        renderer.lineWidth = 4.0

        return renderer
    }
}