Watches for changes to the device's current position.
var watchId = navigator.geolocation.watchPosition(geolocationSuccess,
[geolocationError],
[geolocationOptions]);
- geolocationSuccess: The callback that is called with the current position.
- geolocationError: (Optional) The callback that is called if there was an error.
- geolocationOptions: (Optional) The geolocation options.
- String: returns a watch id that references the watch position interval. The watch id can be used with
geolocation.clearWatch
to stop watching for changes in position.
Function geolocation.watchPosition
is an asynchronous function. It returns the device's current position when a change in position has been detected. When the device has retrieved a new location, the geolocationSuccess
callback is invoked with a Position
object as the parameter. If there is an error, the geolocationError
callback is invoked with a PositionError
object.
- Android
- BlackBerry WebWorks (OS 5.0 and higher)
- iPhone
- Windows Phone 7 ( Mango )
// onSuccess Callback
// This method accepts a `Position` object, which contains
// the current GPS coordinates
//
function onSuccess(position) {
var element = document.getElementById('geolocation');
element.innerHTML = 'Latitude: ' + position.coords.latitude + '<br />' +
'Longitude: ' + position.coords.longitude + '<br />' +
'<hr />' + element.innerHTML;
}
// onError Callback receives a PositionError object
//
function onError(error) {
alert('code: ' + error.code + '\n' +
'message: ' + error.message + '\n');
}
// Options: retrieve the location every 3 seconds
//
var watchID = navigator.geolocation.watchPosition(onSuccess, onError, { frequency: 3000 });
<!DOCTYPE html>
<html>
<head>
<title>Device Properties Example</title>
<script type="text/javascript" charset="utf-8" src="cordova-1.6.0.js"></script>
<script type="text/javascript" charset="utf-8">
// Wait for Cordova to load
//
document.addEventListener("deviceready", onDeviceReady, false);
var watchID = null;
// Cordova is ready
//
function onDeviceReady() {
// Update every 3 seconds
var options = { frequency: 3000 };
watchID = navigator.geolocation.watchPosition(onSuccess, onError, options);
}
// onSuccess Geolocation
//
function onSuccess(position) {
var element = document.getElementById('geolocation');
element.innerHTML = 'Latitude: ' + position.coords.latitude + '<br />' +
'Longitude: ' + position.coords.longitude + '<br />' +
'<hr />' + element.innerHTML;
}
// onError Callback receives a PositionError object
//
function onError(error) {
alert('code: ' + error.code + '\n' +
'message: ' + error.message + '\n');
}
</script>
</head>
<body>
<p id="geolocation">Watching geolocation...</p>
</body>
</html>