Geolocation API Support and Permission Handling

Geolocation API Detection

The Geolocation API provides access to the user's geographic position, enabling location-aware web applications. It requires explicit user permission and works only on secure origins (HTTPS).

Detection

const hasGeolocation = 'geolocation' in navigator;

Getting Position

function getCurrentPosition(options = {}) {
  return new Promise((resolve, reject) => {
    if (!navigator.geolocation) {
      reject(new Error('Geolocation not supported'));
      return;
    }
    navigator.geolocation.getCurrentPosition(
      resolve,
      reject,
      {
        enableHighAccuracy: options.highAccuracy || false,
        timeout: options.timeout || 10000,
        maximumAge: options.maxAge || 0,
      }
    );
  });
}

// Usage
const pos = await getCurrentPosition({ highAccuracy: true });
console.log(pos.coords.latitude, pos.coords.longitude);

Watching Position

const watchId = navigator.geolocation.watchPosition(
  (position) => {
    updateMap(position.coords);
  },
  (error) => {
    console.error('Watch error:', error.code);
  },
  { enableHighAccuracy: true }
);

// Stop watching
navigator.geolocation.clearWatch(watchId);

Position Object

Property	Description
latitude	Decimal degrees
longitude	Decimal degrees
accuracy	Meters (radius of confidence)
altitude	Meters above sea level (optional)
altitudeAccuracy	Meters (optional)
heading	Degrees from north (optional)
speed	Meters per second (optional)

Error Codes

Code	Constant	Meaning
1	PERMISSION_DENIED	User denied permission
2	POSITION_UNAVAILABLE	Location unavailable
3	TIMEOUT	Request timed out

Privacy Considerations

• Always explain why you need location data before requesting it
• Use the minimum accuracy level needed for your use case
• Do not store or transmit location data without user consent
• Provide manual location input as an alternative