HTML5 TUTORIALS - HTML5 Geolocation

HTML5 Geolocation

Method	Description
getCurrentPosition()	This method retrieves the current geographic location of the user.
watchPosition()	This method retrieves periodic updates about the current geographic location of the device.
clearWatch()	This method cancels an ongoing watchPosition call.

Example:


function getLocation() {
   var geolocation = navigator.geolocation;
   geolocation.getCurrentPosition(showLocation, errorHandler);
}

Property	Type	Description
coords	objects	Specifies the geographic location of the device. The location is expressed as a set of geographic coordinates together with information about heading and speed.
coords.latitude	Number	Specifies the latitude estimate in decimal degrees. The value range is [-90.00, +90.00].
coords.longitude	Number	Specifies the longitude estimate in decimal degrees. The value range is [-180.00, +180.00].
coords.altitude	Number	[Optional] Specifies the altitude estimate in meters above the WGS 84 ellipsoid.
coords.accuracy	Number	[Optional] Specifies the accuracy of the latitude and longitude estimates in meters.
coords.altitudeAccuracy	Number	[Optional] Specifies the accuracy of the altitude estimate in meters.
coords.heading	Number	[Optional] Specifies the device's current direction of movement in degrees counting clockwise relative to true north.
coords.speed	Number	[Optional] Specifies the device's current ground speed in meters per second.
timestamp	date	Specifies the time when the location information was retrieved and the Position object created.

Example:


function showLocation( position ) {
  var latitude = position.coords.latitude;
  var longitude = position.coords.longitude;
  ...
}

Property	Type	Description
code	Number	Contains a numeric code for the error.
message	String	Contains a human-readable description of the error.

Code	Constant	Description
0	UNKNOWN_ERROR	The method failed to retrieve the location of the device due to an unknown error.
1	PERMISSION_DENIED	The method failed to retrieve the location of the device because the application does not have permission to use the Location Service.
2	POSITION_UNAVAILABLE	The location of the device could not be determined.
3	TIMEOUT	The method was unable to retrieve the location information within the specified maximum timeout interval.

Example:


function errorHandler( err ) {
  if (err.code == 1) {
    // access is denied
  }
  ...
}


getCurrentPosition(callback, ErrorCallback, options)

Property	Type	Description
enableHighAccuracy	Boolean	Specifies whether the widget wants to receive the most accurate location estimate possible. By default this is false.
timeout	Number	The timeout property is the number of milliseconds your web application is willing to wait for a position.
maximumAge	Number	Specifies the expiry time in milliseconds for cached location information.

Example:


function getLocation() {
   var geolocation = navigator.geolocation;
   geolocation.getCurrentPosition(showLocation, errorHandler,
                                 {maximumAge: 75000});
}