Get Current Latitude and Longitude

In this example, we'll create a page, and when the page is shown it will attempt to retrieve our current position, then display it in an alert dialog, or display the error that occurred.

/**
 * Defines custom routes for my module.
 */
my_module.routing = function() {
  var routes = {};
  routes["my_module.geolocation"] = {
    "path": "/my-module-geolocation",
    "defaults": {
      "_controller": my_module_geolocation_page_controller,
      "_title": "Hello World"
    }
  };
  return routes;
};

/**
 * My geolocation page controller.
 */
function my_module_geolocation_page_controller() {
  return new Promise(function(ok, err) {

    var content = {};

    // Get the current position...
    navigator.geolocation.getCurrentPosition(
    
      // Success
      function (position) {

        // Inspect the position coordinates.
        //console.log(position.coords);

        // Show a generic alert message.
        //dg.alert(
        //    'Latitude: '          + position.coords.latitude          + '\n' +
        //    'Longitude: '         + position.coords.longitude         + '\n' +
        //    'Altitude: '          + position.coords.altitude          + '\n' +
        //    'Accuracy: '          + position.coords.accuracy          + '\n' +
        //    'Altitude Accuracy: ' + position.coords.altitudeAccuracy  + '\n' +
        //    'Heading: '           + position.coords.heading           + '\n' +
        //    'Speed: '             + position.coords.speed             + '\n' +
        //    'Timestamp: '         + position.timestamp                + '\n'
        //);

        // Show a bullet list of coordinate data...

        // Iterate over each coordinate and place them in a list.
        var pieces = ['latitude', 'longitude', 'altitude', 'accuracy', 'altitudeAccuracy', 'heading', 'speed'];
        var items = [];
        for (var i = 0; i < pieces.length; i++) {
          var piece = pieces[i];
          items.push(piece + ': ' + position.coords[piece])
        }

        // Show the date and time the location was retrieved.
        var d = new Date(position.timestamp);
        content['user-location-date'] = {
          _markup: d.toDateString()
        };

        // Show the pieces of the coordinates.
        content['user-location'] = {
          _theme: 'item_list',
          _items: items
        };

        ok(content);

      },
      
      // Error
      function (error) {
        dg.alert(
            'Code: '    + error.code    + '\n' +
            'Message: ' + error.message + '\n'
        );
        ok();
      }
      
    );

  });
}

You could then navigate to this new page in the app to test it out. For example, set the front page with the route of your new page in the settings.js file:

// Set Front Page
drupalgap.settings.front = 'my-module-geolocation';