geolocation

Geolocation

Get a position (or snapshot) with explicit permission. Continuous streams: react-native-realtime-location. Background: react-native-background-location. Reverse address: reverse-geocoding.

Sources

Environment	Typical API
Expo RN	expo-location getCurrentPositionAsync
RN bare	@react-native-community/geolocation or equivalent
Web	navigator.geolocation

Non-negotiable rules

• Request permission first; handle denied/restricted.
• Timeout and maximumAge aware (don't freeze the UI forever).
• Propagate accuracy; discard readings worse than the product threshold when critical.
• Fallback UX if GPS off / no signal (manual input, last known, draggable map).
• Don't block first paint unnecessarily — async + skeleton.

Flow

check services enabled
  → request permission
  → getCurrentPosition({ accuracy, timeout, maximumAge })
  → { lat, lng, accuracy, altitude?, heading?, speed?, timestamp }

• iOS: When-In-Use is enough for a snapshot.
• Android: fine vs coarse depending on usage; fine for pickup pin.

Typed errors

• permission_denied
• services_disabled
• timeout
• unavailable

Map to actionable copy (“Turn on location” / “Open Settings”).

Privacy

• Minimize retention; don't send position without feature context.
• Document usage in the policy when persisting to the backend.

Anti-patterns

• Assuming success without checking permission
• enableHighAccuracy: true always without need (battery)
• Error swallow with 0,0 in the Gulf of Guinea
• Requesting Always just for a one-off get

Completion criteria

• Reliable snapshot with permission granted
• All main errors with UX
• Accuracy available to consumers (map/matching)
• Works on iOS and Android (and web if in scope)