Complete Geolocation.js

geolocation.js

/*
 *  A Geolocation object
 *  
 *  Note: Uses GPS or similar hardware for data if available through 
 *        the browser, but will fall back to using (Google) geolocation
 *        services with current IP address automatically.
 *        
 *  @property   {boolean}   supported   If the geolocation functions are available in the current context
 *  @property   {function}  onsuccess   The function to be called if the geolocation services are successful
 *  @property   {function}  onerror     The function to be called if an error occurs
 *  @property   {object}    options     The options {enableHighAccuracy, maximumAge, timeout} to apply to geolocation functions
 *  @property   {object}    position    The last recorded geolocation data (default is 0)
 */

var Geolocation = (function(self) {

  self.supported = ("geolocation" in navigator);

  self.onsuccess = function() {};
  self.onerror = function() {};

  /*
   * The accuracy, maximum age, and timeout for the geolocation data
   */
  self.options = {
    enableHighAccuracy: true,
    maximumAge: 30000,
    timeout: 27000
  };

  /*
   * The last recorded geolocation
   */
  self.position = {
    latitude: 0,
    longitude: 0
  };

  /*
   * The watchPosition function ID, if set
   */
  var wpid = null;

  /*
   * Gets the current geolocation position, recording the data
   *  and calling associated functions
   */
  self.getCurrentPosition = function() {
    if (self.supported) {
      navigator.geolocation.getCurrentPosition(function(position) {
        self.position.latitude = position.coords.latitude;
        self.position.longitude = position.coords.longitude;
        self.onsuccess.apply(this, arguments);
      }, self.onerror, self.options);
    }
  };

  /*
   * Watches the geolocation position, calling the onsuccess function
   *  according to the maximumAge and timeout options
   */
  self.watchPosition = function() {
    if (self.supported) {
      wpid = navigator.geolocation.watchPosition(function(position) {
        self.position.latitude = position.coords.latitude;
        self.position.longitude = position.coords.longitude;
        self.onsuccess.apply(this, arguments);
      }, self.onerror, self.options);
    }
  };

  /*
   * Clears (if set) the currently watched position function
   */
  self.clearPosition = function() {
    if (self.supported && wpid !== null) {
      navigator.geolocation.clearWatch(wpid);
    }
  };

  return self;
  
})(Geolocation || {});