Summary - Location
- React Native course
- Advanced
- Lesson 24/83
- 5 min
Combine expo-location, getCurrentPositionAsync and watchPositionAsync to write a location tracking app.
Summary - Location
In this group you learned to install the expo-location package, ask for location permission, get the current location with getCurrentPositionAsync, track continuously with watchPositionAsync and convert an address to a coordinate with geocodeAsync. The core of a location app is these five pieces.
In the summary we will merge permission, current location and address resolution in a single app. These three pieces together form a real location flow. Let us merge them now.
Practice Summary - Get the current location
Complete the getLocation function. Call const loc = await Location.getCurrentPositionAsync({ accuracy: Location.Accuracy.High }). Return an object with return { latitude: loc.coords.latitude, longitude: loc.coords.longitude }.
Starter code
import * as Location from 'expo-location';
export async function getLocation() {
// get the current location and return lat/lng
}Sample solution
const loc = await Location.getCurrentPositionAsync({
accuracy: Location.Accuracy.High,
});
return { latitude: loc.coords.latitude, longitude: loc.coords.longitude };Practice Summary - Address to coordinate
Complete the geocodeAddress function. Call const results = await Location.geocodeAsync(address). Return the first result with return results[0].
Starter code
import * as Location from 'expo-location';
export async function geocodeAddress(address) {
// convert the address to a coordinate and return the first result
}Sample solution
const results = await Location.geocodeAsync(address);
return results[0];Questions and answers
Review the lesson questions together with their answers. To test yourself, solve the lesson interactively.
1 Write the permission function
const permission = await Location.____();const permission = await Location.requestForegroundPermissionsAsync();Explanation: This function asks for location permission.
2 Match each flow part to its role
| Term | Meaning |
|---|---|
requestForegroundPermissionsAsync |
Location permission |
getCurrentPositionAsync |
Current location |
watchPositionAsync |
Continuous tracking |
geocodeAsync |
Address to coordinate |