import { Observable } from 'rxjs';

// #docregion

// Create an Observable that will start listening to geolocation updates
// when a consumer subscribes.
const locations = new Observable((observer) => {
  // Get the next and error callbacks. These will be passed in when
  // the consumer subscribes.
  const {next, error} = observer;
  let watchId;

  // Simple geolocation API check provides values to publish
  if ('geolocation' in navigator) {
    watchId = navigator.geolocation.watchPosition(next, error);
  } else {
    error('Geolocation not available');
  }

  // When the consumer unsubscribes, clean up data ready for next subscription.
  return {unsubscribe() { navigator.geolocation.clearWatch(watchId); }};
});

// Call subscribe() to start listening for updates.
const locationsSubscription = locations.subscribe({
  next(position) { console.log('Current Position: ', position); },
  error(msg) { console.log('Error Getting Location: ', msg); }
});

// Stop listening for location after 10 seconds
setTimeout(() => { locationsSubscription.unsubscribe(); }, 10000);
// #enddocregion