[javascript] Get GPS location from the web browser

I am developing a mobile based web-site, there I have integrated Google Maps, I need to fill the 'From' field of Google Maps dynamically.

Is it possible to get the GPS location from web browser and fill it up in the 'From' field of a Google Map dynamically?

Use this, and you will find all informations at http://www.w3schools.com/html/html5_geolocation.asp

<script>
var x = document.getElementById("demo");
function getLocation() {
    if (navigator.geolocation) {
        navigator.geolocation.getCurrentPosition(showPosition);
    } else {
        x.innerHTML = "Geolocation is not supported by this browser.";
    }
}
function showPosition(position) {
    x.innerHTML = "Latitude: " + position.coords.latitude + 
    "<br>Longitude: " + position.coords.longitude; 
}
</script>

Let's use the latest fat arrow functions:

navigator.geolocation.getCurrentPosition((loc) => {
  console.log('The location in lat lon format is: [', loc.coords.latitude, ',', loc.coords.longitude, ']');
})

Observable

/*
  function geo_success(position) {
    do_something(position.coords.latitude, position.coords.longitude);
  }

  function geo_error() {
    alert("Sorry, no position available.");
  }

  var geo_options = {
    enableHighAccuracy: true,
    maximumAge        : 30000,
    timeout           : 27000
  };

  var wpid = navigator.geolocation.watchPosition(geo_success, geo_error, geo_options);
  */
  getLocation(): Observable<Position> {
    return Observable.create((observer) => {
      const watchID = navigator.geolocation.watchPosition((position: Position) => {
        observer.next(position);
      });
      return () => {
        navigator.geolocation.clearWatch(watchID);
      };
    });
  }

  ngOnDestroy() {
    this.sub.unsubscribe();
  }

There is the GeoLocation API, but browser support is rather thin on the ground at present. Most sites that care about such things use a GeoIP database (with the usual provisos about the inaccuracy of such a system). You could also look at third party services requiring user cooperation such as FireEagle.

If you use the Geolocation API, it would be as simple as using the following code.

navigator.geolocation.getCurrentPosition(function(location) {
  console.log(location.coords.latitude);
  console.log(location.coords.longitude);
  console.log(location.coords.accuracy);
});

You may also be able to use Google's Client Location API.

This issue has been discussed in Is it possible to detect a mobile browser's GPS location? and Get position data from mobile browser. You can find more information there.

To give a bit more specific answer. HTML5 allows you to get the geo coordinates, and it does a pretty decent job. Overall the browser support for geolocation is pretty good, all major browsers except ie7 and ie8 (and opera mini). IE9 does the job but is the worst performer. Checkout caniuse.com:

http://caniuse.com/#search=geol

Also you need the approval of your user to access their location, so make sure you check for this and give some decent instructions in case it's turned off. Especially for Iphone turning permissions on for Safari is a bit cumbersome.