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Geolocation: watchPosition() method

Secure context: This feature is available only in secure contexts (HTTPS), in some or all supporting browsers.

The Geolocation method watchPosition() method is used to register a handler function that will be called automatically each time the position of the device changes. You can also, optionally, specify an error handling callback function.

Syntax

watchPosition(success)
watchPosition(success, error)
watchPosition(success, error, options)

Parameters

success: A callback function that takes a GeolocationPosition object as an input parameter.
error Optional: An optional callback function that takes a GeolocationPositionError object as an input parameter.
options Optional: An optional object that provides configuration options for the location watch. See Geolocation.getCurrentPosition() for more details on possible options.

Return value

An integer ID that identifies the registered handler. The ID can be passed to the Geolocation.clearWatch() to unregister the handler.

Examples

let id;
let target;
let options;

function success(pos) {
  const crd = pos.coords;

  if (target.latitude === crd.latitude && target.longitude === crd.longitude) {
    console.log("Congratulations, you reached the target");
    navigator.geolocation.clearWatch(id);
  }
}

function error(err) {
  console.error(`ERROR(${err.code}): ${err.message}`);
}

target = {
  latitude: 0,
  longitude: 0,
};

options = {
  enableHighAccuracy: false,
  timeout: 5000,
  maximumAge: 0,
};

id = navigator.geolocation.watchPosition(success, error, options);

Specifications

Specification
Geolocation API # watchposition-method

Browser compatibility