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.
watchPosition(success)
watchPosition(success, error)
watchPosition(success, error, options)
An integer ID that identifies the registered handler. The ID can be passed to the Geolocation.clearWatch()
to unregister the handler.
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);