# Advanced navigation app In this example, we are going to create an App that allows users to long press on the map to add a destination to request routes and display the routes on the map, this app also enables route selection from alternative routes, lastly, users can start navigation by tapping the “Start” button, then the app will present the **NavigationViewController** to begin turn-by-turn navigation. ![documentation image](https://static.nextbillion.io/docs-next/docs/navigation/ios/advanced-navigation-app1.webp) For all code examples, refer to [Navigation Code Examples](https://github.com/nextbillion-ai/nb-navigation-android-demo) **AdvancedNavigationViewController** [view code](https://github.com/nextbillion-ai/ios-navigation-demo/blob/main/navigation-ios-demo/AdvancedNavigationViewController.swift) ```swift import UIKit import NbmapNavigation import NbmapCoreNavigation import Nbmap class AdvancedNavigationViewController: UIViewController, NGLMapViewDelegate { var navigationMapView: NavigationMapView? { didSet { oldValue?.removeFromSuperview() if let navigationMapView = navigationMapView { view.insertSubview(navigationMapView, at: 0) } } } var routes : [Route]? { didSet { guard routes != nil else{ startButton.isEnabled = false return } startButton.isEnabled = true guard let routes = routes, let current = routes.first else { navigationMapView?.removeRoutes(); return } navigationMapView?.showRoutes(routes) navigationMapView?.showWaypoints(current) navigationMapView?.showRouteDurationSymbol(routes) } } var startButton = UIButton() override func viewDidLoad() { super.viewDidLoad() self.navigationMapView = NavigationMapView(frame: view.bounds) navigationMapView?.userTrackingMode = .followWithHeading let singleTap = UILongPressGestureRecognizer(target: self, action: #selector(didLongPress(tap:))) navigationMapView?.gestureRecognizers?.filter({ $0 is UILongPressGestureRecognizer }).forEach(singleTap.require(toFail:)) navigationMapView?.addGestureRecognizer(singleTap) navigationMapView?.delegate = self navigationMapView?.navigationMapDelegate = self setupStartButton() self.view.setNeedsLayout() } func setupStartButton() { startButton.setTitle("Start", for: .normal) startButton.layer.cornerRadius = 5 startButton.contentEdgeInsets = UIEdgeInsets(top: 5, left: 5, bottom: 5, right: 5) startButton.backgroundColor = .blue startButton.addTarget(self, action: #selector(tappedButton), for: .touchUpInside) view.addSubview(startButton) startButton.translatesAutoresizingMaskIntoConstraints = false startButton.bottomAnchor.constraint(equalTo: view.safeAreaLayoutGuide.bottomAnchor, constant: -50).isActive = true startButton.centerXAnchor.constraint(equalTo: view.safeAreaLayoutGuide.centerXAnchor).isActive = true startButton.titleLabel?.font = UIFont.systemFont(ofSize: 25) } @objc func tappedButton(sender: UIButton) { guard let routes = self.routes else { return } let navigationService = NBNavigationService(routes: routes, routeIndex: 0) let navigationOptions = NavigationOptions(navigationService: navigationService) let navigationViewController = NavigationViewController(for: routes,navigationOptions: navigationOptions) // Set the delegate of navigationViewController to subscribe for NavigationView's events, This is optional // navigationViewController.delegate = weakSelf navigationViewController.modalPresentationStyle = .fullScreen present(navigationViewController, animated: true, completion: nil) } @objc func didLongPress(tap: UILongPressGestureRecognizer) { guard let navigationMapView = navigationMapView, tap.state == .began else { return } let coordinates = navigationMapView.convert(tap.location(in: navigationMapView), toCoordinateFrom: navigationMapView) let destination = Waypoint(coordinate: coordinates, name: "\(coordinates.latitude),\(coordinates.longitude)") addNewDestinationIcon(coordinates: coordinates) guard let currentLocation = navigationMapView.userLocation?.coordinate else { return} let currentWayPoint = Waypoint.init(coordinate: currentLocation, name: "My Location") requestRoutes(origin: currentWayPoint, destination: destination) } func addNewDestinationIcon(coordinates: CLLocationCoordinate2D){ guard let mapView = navigationMapView else { return } if let annotation = mapView.annotations?.last { mapView.removeAnnotation(annotation) } let annotation = NGLPointAnnotation() annotation.coordinate = coordinates mapView.addAnnotation(annotation) } func requestRoutes(origin: Waypoint, destination: Waypoint){ let options = NavigationRouteOptions(origin: origin, destination: destination) /** Sets whether the route contains an alternate route By default, it set to `false` */ options.includesAlternativeRoutes = true /** The route classes that the calculated routes will avoid. We can set an array road class to avoid. This property can be set to `.toll`,`.ferry`,`.highway` By default , this property is set to empty */ options.roadClassesToAvoid = [.toll,.ferry,.highway] /** Set up the navigation measurement unit This property should be set to `.metric` or `.imperial` By default, this property is set to the unit following with the current system locale. */ options.distanceMeasurementSystem = .imperial /** Set specifying the primary mode of transportation for the routes. This property should be set to `NBNavigationModeCar`, `NBNavigationModeAuto`, `NBNavigationModeBike`, `NBNavigationMode4W`,`NBNavigationMode2W`,`NBNavigationMode6W`, or `NBNavigationModeEscooter`. The default value of this property is `NBNavigationMode4W`, which specifies driving directions. */ options.profileIdentifier = NBNavigationMode.mode4W /** Set the departureTime of the route, By default, it sets the current timestamp since 1970 */ options.departureTime = Int(Date().timeIntervalSince1970) /** Set up the locale in which the route's instructions are written. If you use NbmapDirections.swift with the Nbmap Directions API, this property affects the sentence contained within the `RouteStep.instructions` property, but it does not affect any road names contained in that property or other properties such as `RouteStep.name`. The Navigation API can provide instructions in [a number of languages]. Set this property to `Bundle.main.preferredLocalizations.first` or `Locale.autoupdatingCurrent` to match the application's language or the system language, respectively. By default, this property is set to the current system locale. */ options.locale = Locale.autoupdatingCurrent /** Set map options, This property may make the ETA more accurate. If set to `NBMapOption.valhala`, shapeFormat needs to be set to `polyline`. By default, the value of this property is `NBMapOption.none` */ options.mapOption = NBMapOption.none /** Format of the data from which the shapes of the returned route and its steps are derived. This property has no effect on the returned shape objects, although the choice of format can significantly affect the size of the underlying HTTP response. The default value of this property is `polyline6`. */ options.shapeFormat = .polyline6 Directions.shared.calculate(options) { [weak self] routes, error in guard let weakSelf = self else { return } guard error == nil else { print(error!) return } guard let routes = routes else { return } // Process or display routes information.For example, display the routes, waypoints and duration symbol on the map weakSelf.navigationMapView?.showRoutes(routes) weakSelf.navigationMapView?.showRouteDurationSymbol(routes) guard let current = routes.first else { return } weakSelf.navigationMapView?.showWaypoints(current) weakSelf.routes = routes } } } extension AdvancedNavigationViewController: NavigationMapViewDelegate { // Delegate method called when the user selects a route func navigationMapView(_ mapView: NavigationMapView, didSelect route: Route) { guard let routes = routes else { return } guard let index = routes.firstIndex(where: { $0 == route }) else { return } self.routes!.remove(at: index) self.routes!.insert(route, at: 0) } } ``` The code defines a custom view controller called **AdvancedNavigationViewController** that inherits from **UIViewController** and conforms to the **NGLMapViewDelegate** protocol. The purpose of this custom view controller is to implement an advanced navigation experience using **NbmapNavigation**, **NbmapCoreNavigation**, **NbmapDirections**, and **Nbmap** libraries. - Import statements: The necessary frameworks are imported at the beginning of the file. - **navigationMapView:** A property for the NavigationMapView instance. When its value is set, the old instance is removed from the view hierarchy, and the new one is inserted as a subview. - **routes:** An array of Route objects. When its value is set, the start button's state is updated accordingly, and the route, waypoints, and route duration symbols are shown on the navigation map view. - **startButton:** A UIButton that initiates navigation when tapped. - **viewDidLoad():** This method sets up the view controller after the view is loaded. It creates a NavigationMapView, adds a long press gesture recognizer, sets up the start button, and calls view.setNeedsLayout() to invalidate the current layout of the receiver and trigger a layout update during the next update cycle. - **setupStartButton():** This method configures the start button's appearance and adds a target to handle the button tap. - **tappedButton(sender:):** The action method for the start button tap. It initializes a NBNavigationService, sets up navigation options and a NavigationViewController, and then presents the navigation view controller. - **didLongPress(tap:):** The method that handles the long press gesture. It converts the tap location to coordinates and then adds a new destination based on the coordinates. It also makes a request for routes between the user's current location and the destination. - **addNewDestinationIcon(coordinates:):** This method adds a new destination annotation to the navigation map view. - **requestRoutes(origin:destination:):** This method requests routes between the given origin and destination using the specified options. - An extension of **AdvancedNavigationViewController** that conforms to the **NavigationMapViewDelegate** protocol. It contains the **navigationMapView(_:didSelect:)** delegate method to handle when the user selects a route from the displayed routes. ![ios-sdk-7](https://static.nextbillion.io/docs-next/docs/navigation/ios/advanced-navigation-app2.webp)