geolocation-service.js

export default {
  name: 'geolocation-service',
  initialize: function(container, app) {
    app.inject('route', 'geolocationService', 'service:geolocation');
    app.inject('controller', 'geolocationService', 'service:geolocation');
  }
};

geolocation.js

import Ember from 'ember';

export default Ember.Object.extend({
	hasLocation: false,
	location: null,
	init: function() { return this.get('getPosition'); },
	getPosition: function() {
		var service = this;
		return new Ember.RSVP.Promise(function(resolve, reject){
			if (service.get('supportsGeolocation')) {
				if (service.get('hasLocation')) {
					resolve(service.get('location'));
				} else {
					navigator.geolocation.watchPosition(function(position) {
						service.set('location', position);
						service.set('hasLocation', true);
						resolve(position);
					}, function(error) {
						reject(error);
					});
				}
			} else {
				reject(new Error("Browser does not support geolocation."));
			}
		});
	},
	supportsGeolocation: function() {
		return 'geolocation' in window.navigator;
	}
});