Google Maps iOS SDK, Getting Directions between 2 locations

Question

While I am using Google Maps SDK, I am trying to get driving direction between two locations on iOS. I know we can do this using two methods:-

1.) Using URL Scheme,

Answer 1

Using Swift I definitely solved in this way.
My purpose was finding distance between two coordinates:

import AFNetworking 

/**
 Calculate distance between two valid coordinates

 - parameter origin:      origin coordinates
 - parameter destination: destination coordinates
 - parameter completion:  completion callback
 */
func calculateDistance(origin origin: CLLocation, destination: CLLocation, completion: (distance: Double?) -> Void) {

    let service = "https://maps.googleapis.com/maps/api/directions/json"
    let originLat = origin.coordinate.latitude
    let originLong = origin.coordinate.longitude
    let destLat = destination.coordinate.latitude
    let destLong = destination.coordinate.longitude
    let urlString = "\(service)?origin=\(originLat),\(originLong)&destination=\(destLat),\(destLong)&mode=driving&units=metric&sensor=true&key="
    let directionsURL = NSURL(string: urlString)

    let request = NSMutableURLRequest(URL: directionsURL!)

    request.HTTPMethod = "GET"
    request.addValue("application/json", forHTTPHeaderField: "Content-Type")
    request.addValue("application/json", forHTTPHeaderField: "Accept")
    let operation = AFHTTPRequestOperation(request: request)
    operation.responseSerializer = AFJSONResponseSerializer()

    operation.setCompletionBlockWithSuccess({ (operation: AFHTTPRequestOperation!, responseObject: AnyObject!) -> Void in

        if let result = responseObject as? NSDictionary {
            if let routes = result["routes"] as? [NSDictionary] {
                if let lines = routes[0]["overview_polyline"] as? NSDictionary {
                    if let points = lines["points"] as? String {
                        let path = GMSPath(fromEncodedPath: points)
                        let distance = GMSGeometryLength(path)
                        print("wow \(distance / 1000) KM")

                    }
                }
            }
        }
        }) { (operation: AFHTTPRequestOperation!, error: NSError!)  -> Void in
            print("\(error)")
    }

    operation.start()

}