How to draw routes between two locations in google maps iOS swift

Question

I'm using google maps in my iOS swift project. I want to draw a path between two locations on the map (Not straight line). Any idea how to do that ?

Ashish Shah · Answer 1 · 2023-02-04T15:41:19.287

29

To draw polyline between two locations on Google Map in Swift.

//Pass your source and destination coordinates in this method.

func fetchRoute(from source: CLLocationCoordinate2D, to destination: CLLocationCoordinate2D) {
    
    let session = URLSession.shared
    
    let url = URL(string: "http://maps.googleapis.com/maps/api/directions/json?origin=\(source.latitude),\(source.longitude)&destination=\(destination.latitude),\(destination.longitude)&sensor=false&mode=driving")!
    
    let task = session.dataTask(with: url, completionHandler: {
        (data, response, error) in
        
        guard error == nil else {
            print(error!.localizedDescription)
            return
        }
        
        guard let jsonResponse = try? JSONSerialization.jsonObject(with: data!, options: .allowFragments) as? [String: Any] else {
            print("error in JSONSerialization")
            return
        }
        
        guard let routes = jsonResponse["routes"] as? [Any] else {
            return
        }
        
        guard let route = routes[0] as? [String: Any] else {
            return
        }

        guard let overview_polyline = route["overview_polyline"] as? [String: Any] else {
            return
        }
        
        guard let polyLineString = overview_polyline["points"] as? String else {
            return
        }
        
        //Call this method to draw path on map
        self.drawPath(from: polyLineString)
    })
    task.resume()
}

To draw polyline on map .

func drawPath(from polyStr: String){
    let path = GMSPath(fromEncodedPath: polyStr)
    let polyline = GMSPolyline(path: path)
    polyline.strokeWidth = 3.0
    polyline.map = mapView // Google MapView
}

edited Feb 04 '23 at 15:41

answered Feb 09 '17 at 14:32

Ashish Shah

2,361
1
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20

2

I appreciate Good Answer – Darshan Mothreja Feb 10 '17 at 09:56
url should be https if your using authorized key – Mr.G Sep 24 '17 at 05:48
2

it says "Initializer for conditional binding must have Optional type, not '[String : Any]'" at jsonResult line – Dharmik Nov 27 '19 at 09:41
@Dharmik Add your code snippet where you are getting this warning. – Ashish Shah Nov 27 '19 at 11:10
I have copy pasted your code in my project, it gives error at `guard let jsonResult = try? JSONSerialization.jsonObject(with: data!, options: .allowFragments) as? [String: Any], let jsonResponse = jsonResult` I am getting error at `let jsonResponse` in your code, I don't understand what is issue – Dharmik Nov 27 '19 at 16:35
Did you figure out this issue? ^^ – Noah Omdal Dec 18 '19 at 14:54
@Dharmik for avoid this error, delete `let jsonResponse = jsonResult` because `jsonResult` is not optional, and use `jsonResult` instead of `jsonResponse` – iGhost May 13 '21 at 22:27
@Dharmik, just put "let jsonResponse = jsonResult" after guard block. – Vladimir Sukanica Jun 23 '21 at 10:24
1

remove `let jsonResponse = jsonResult` and replace `guard let jsonResult = ...` with `guard let jsonResponse = ...`. The mistake is the author of this answer tries to unwrap the same optional twice. – Gargo Feb 02 '23 at 07:42

Sagar Sukode · Answer 2 · 2017-05-25T06:51:35.567

Showing Multiple-routes between two locations in google maps in swift 3.0 with camera zoom:

    let origin = "\(startLocation.coordinate.latitude),\(startLocation.coordinate.longitude)"
    let destination = "\(destinationLocation.coordinate.latitude),\(destinationLocation.coordinate.longitude)"

    let urlString = "https://maps.googleapis.com/maps/api/directions/json?origin=\(origin)&destination=\(destination)&mode=driving&key=API_KEY"

    let url = URL(string: urlString)
    URLSession.shared.dataTask(with: url!, completionHandler: {
        (data, response, error) in
        if(error != nil){
            print("error")
        }else{
            do{
                let json = try JSONSerialization.jsonObject(with: data!, options:.allowFragments) as! [String : AnyObject]
                let routes = json["routes"] as! NSArray
                self.mapView.clear()

                OperationQueue.main.addOperation({
                    for route in routes
                    {
                        let routeOverviewPolyline:NSDictionary = (route as! NSDictionary).value(forKey: "overview_polyline") as! NSDictionary
                        let points = routeOverviewPolyline.object(forKey: "points")
                        let path = GMSPath.init(fromEncodedPath: points! as! String)
                        let polyline = GMSPolyline.init(path: path)
                        polyline.strokeWidth = 3

                        let bounds = GMSCoordinateBounds(path: path!)
                        self.mapView!.animate(with: GMSCameraUpdate.fit(bounds, withPadding: 30.0))

                        polyline.map = self.mapView

                    }
                })
            }catch let error as NSError{
                print("error:\(error)")
            }
        }
    }).resume()

@sagar sukode Can we draw just a single route. – Akhtar Sep 18 '17 at 08:49 — Akhtar, Sep 18 '17 at 08:49

score 3 · Answer 3 · answered Nov 01 '19 at 07:54

Above all answers can draw routes but there is a way that you can draw accurate route using directions API.Here is the code hopefully it will help for you.

func getRouteSteps(from source: CLLocationCoordinate2D, to destination: CLLocationCoordinate2D) {

    let session = URLSession.shared

    let url = URL(string: "https://maps.googleapis.com/maps/api/directions/json?origin=\(source.latitude),\(source.longitude)&destination=\(destination.latitude),\(destination.longitude)&sensor=false&mode=driving&key=\(Your_API_Key)")!

    let task = session.dataTask(with: url, completionHandler: {
        (data, response, error) in

        guard error == nil else {
            print(error!.localizedDescription)
            return
        }

        guard let jsonResult = try? JSONSerialization.jsonObject(with: data!, options: .allowFragments) as? [String: Any] else {

            print("error in JSONSerialization")
            return

        }



        guard let routes = jsonResult["routes"] as? [Any] else {
            return
        }

        guard let route = routes[0] as? [String: Any] else {
            return
        }

        guard let legs = route["legs"] as? [Any] else {
            return
        }

        guard let leg = legs[0] as? [String: Any] else {
            return
        }

        guard let steps = leg["steps"] as? [Any] else {
            return
        }
          for item in steps {

            guard let step = item as? [String: Any] else {
                return
            }

            guard let polyline = step["polyline"] as? [String: Any] else {
                return
            }

            guard let polyLineString = polyline["points"] as? String else {
                return
            }

            //Call this method to draw path on map
            DispatchQueue.main.async {
                self.drawPath(from: polyLineString)
            }

        }
    })
    task.resume()
}

And then

    //MARK:- Draw Path line
func drawPath(from polyStr: String){
    let path = GMSPath(fromEncodedPath: polyStr)
    let polyline = GMSPolyline(path: path)
    polyline.strokeWidth = 3.0
    polyline.map = mapView // Google MapView


    let cameraUpdate = GMSCameraUpdate.fit(GMSCoordinateBounds(coordinate: sourceLocationCordinates, coordinate: destinationLocationCordinates))
    mapView.moveCamera(cameraUpdate)
    let currentZoom = mapView.camera.zoom
    mapView.animate(toZoom: currentZoom - 1.4)
}

Note: I have added sourcesLocationCordinates and destinationLocationCordinates variables.Don't forget to replace them with your source and destination.Hopefully this will help you making perfect route line.

score 1 · Answer 4 · edited Jul 26 '18 at 15:42

Create a new Swift file copy this code, that's it call then drawPolygon() method from map view for polygon line.

import GoogleMaps

private struct MapPath : Decodable{
    var routes : [Route]?
}

private struct Route : Decodable{ 
    var overview_polyline : OverView?
}

private struct OverView : Decodable {
    var points : String?
}

extension GMSMapView {

    //MARK:- Call API for polygon points

    func drawPolygon(from source: CLLocationCoordinate2D, to destination: CLLocationCoordinate2D){

        let config = URLSessionConfiguration.default
        let session = URLSession(configuration: config)

        guard let url = URL(string: "https://maps.googleapis.com/maps/api/directions/json?origin=\(source.latitude),\(source.longitude)&destination=\(destination.latitude),\(destination.longitude)&sensor=false&mode=driving") else {
            return
        }

        DispatchQueue.main.async {

            session.dataTask(with: url) { (data, response, error) in

                guard data != nil else {
                    return
                }
                do {

                    let route = try JSONDecoder().decode(MapPath.self, from: data!)

                    if let points = route.routes?.first?.overview_polyline?.points {
                        self.drawPath(with: points)
                    }
                    print(route.routes?.first?.overview_polyline?.points)

                } catch let error {

                    print("Failed to draw ",error.localizedDescription)
                }
                }.resume()
            }
    }

    //MARK:- Draw polygon

    private func drawPath(with points : String){

        DispatchQueue.main.async {

            let path = GMSPath(fromEncodedPath: points)
            let polyline = GMSPolyline(path: path)
            polyline.strokeWidth = 3.0
            polyline.strokeColor = .red
            polyline.map = self

        }
    }
}

score 0 · Answer 5 · answered Nov 26 '17 at 10:04

This piece of code will work right for you. Don't forget to change your API key and mode (walking, driving).

func draw(src: CLLocationCoordinate2D, dst: CLLocationCoordinate2D){

    let config = URLSessionConfiguration.default
    let session = URLSession(configuration: config)

    let url = URL(string: "https://maps.googleapis.com/maps/api/directions/json?origin=\(src.latitude),\(src.longitude)&destination=\(dst.latitude),\(dst.longitude)&sensor=false&mode=walking&key=**YOUR_KEY**")!

    let task = session.dataTask(with: url, completionHandler: {
        (data, response, error) in
        if error != nil {
            print(error!.localizedDescription)
        } else {
            do {
                if let json : [String:Any] = try JSONSerialization.jsonObject(with: data!, options: .allowFragments) as? [String: Any] {

                    let preRoutes = json["routes"] as! NSArray
                    let routes = preRoutes[0] as! NSDictionary
                    let routeOverviewPolyline:NSDictionary = routes.value(forKey: "overview_polyline") as! NSDictionary
                    let polyString = routeOverviewPolyline.object(forKey: "points") as! String

                    DispatchQueue.main.async(execute: {
                        let path = GMSPath(fromEncodedPath: polyString)
                        let polyline = GMSPolyline(path: path)
                        polyline.strokeWidth = 5.0
                        polyline.strokeColor = UIColor.green
                        polyline.map = mapView    
                    })
                }

            } catch {
                print("parsing error")
            }
        }
    })
    task.resume()
}

How to draw routes between two locations in google maps iOS swift

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