Geolocation clearWatch() API


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Description

The clearWatch method cancels an ongoing watchPosition call. When cancelled, the watchPosition call stops retrieving updates about the current geographic location of the device.

Syntax

Here is the syntax of this method:

clearWatch(watchId);

Parameters

Here is the detail of parameters:

  • watchId : This specifies the unique ID of the watchPosition call to cancel. The ID is returned by the watchPosition call.

Return value

The clearWatch method does not return a value.

Example

<!DOCTYPE HTML>
<head>
<script type="text/javascript">
var watchID;
var geoLoc;

function showLocation(position) {
  var latitude = position.coords.latitude;
  var longitude = position.coords.longitude;
  alert("Latitude : " + latitude + " Longitude: " + longitude);
}

function errorHandler(err) {
  if(err.code == 1) {
    alert("Error: Access is denied!");
  }else if( err.code == 2) {
    alert("Error: Position is unavailable!");
  }
}
function getLocationUpdate(){

   if(navigator.geolocation){
      // timeout at 60000 milliseconds (60 seconds)
      var options = {timeout:60000};
      geoLoc = navigator.geolocation;
      watchID = geoLoc.watchPosition(showLocation, 
                                     errorHandler,
                                     options);
   }else{
      alert("Sorry, browser does not support geolocation!");
   }
}
function stopWatch(){
   geoLoc.clearWatch(watchID);
}
</script>
</head>
<html>
<body>
   <form>
     <input type="button" onclick="getLocationUpdate();"  
                             value="Watch Update"/>
     <input type="button" onclick="stopWatch();"  
                             value="Stop Watch"/>
   </form>
</body>
</html>

This will produce following result −

To learn above concept - Do Online Practice using latest version of either Opera or Firefox.


html5_geolocation.htm

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