Google Maps API V3 : How show the direction from a point A to point B (Blue line)?

Question

I have latitude and longitude for 2 points on database, I want my Google Map to display a route from point A to point B...

Just like we see here (Google Maps Directions)

How to draw that direction line on map ?

Answer 1

Use directions service of Google Maps API v3. It's basically the same as directions API, but nicely packed in Google Maps API which also provides convenient way to easily render the route on the map.

Information and examples about rendering the directions route on the map can be found in rendering directions section of Google Maps API v3 documentation.

Answer 2

Using Javascript

I created a working demo that shows how to use the Google Maps API Directions Service in Javascript through a

• DirectionsService object to send and receive direction requests
• DirectionsRenderer object to render the returned route on the map

function initMap() {    var pointA = new google.maps.LatLng(51.7519, -1.2578),      pointB = new google.maps.LatLng(50.8429, -0.1313),      myOptions = {        zoom: 7,        center: pointA      },      map = new google.maps.Map(document.getElementById('map-canvas'), myOptions),      // Instantiate a directions service.      directionsService = new google.maps.DirectionsService,      directionsDisplay = new google.maps.DirectionsRenderer({        map: map      }),      markerA = new google.maps.Marker({        position: pointA,        title: "point A",        label: "A",        map: map      }),      markerB = new google.maps.Marker({        position: pointB,        title: "point B",        label: "B",        map: map      });      // get route from A to B    calculateAndDisplayRoute(directionsService, directionsDisplay, pointA, pointB);    }        function calculateAndDisplayRoute(directionsService, directionsDisplay, pointA, pointB) {    directionsService.route({      origin: pointA,      destination: pointB,      travelMode: google.maps.TravelMode.DRIVING    }, function(response, status) {      if (status == google.maps.DirectionsStatus.OK) {        directionsDisplay.setDirections(response);      } else {        window.alert('Directions request failed due to ' + status);      }    });  }    initMap();

    html,      body {        height: 100%;        margin: 0;        padding: 0;      }      #map-canvas {        height: 100%;        width: 100%;      }

<script src="https://maps.googleapis.com/maps/api/js?sensor=false"></script>    <div id="map-canvas"></div>

Also on Jsfiddle: http://jsfiddle.net/user2314737/u9no8te4/

Using Google Maps Web Services

You can use the Web Services using an API_KEY issuing a request like this:

https://maps.googleapis.com/maps/api/directions/json?origin=Toronto&destination=Montreal&key=API_KEY

An API_KEY can be obtained in the Google Developer Console with a quota of 2,500 free requests/day.

A request can return JSON or XML results that can be used to draw a path on a map.

Official documentation for Web Services using the Google Maps Directions API are here