geocoding services for react native

npm install --save react-native-geocoder

1. In the XCode's "Project navigator", right click on Libraries folder under your project ➜ Add Files to <...>
2. Go to node_modules ➜ react-native-geocoder and add ios/RNGeocoder.xcodeproj file
3. Add libRNGeocoder.a to "Build Phases" -> "Link Binary With Libraries"

1. In android/setting.gradle

...
include ':react-native-geocoder', ':app'
project(':react-native-geocoder').projectDir = new File(rootProject.projectDir, '../node_modules/react-native-geocoder/android')

3. In android/app/build.gradle

...
dependencies {
    ...
    compile project(':react-native-geocoder')
}

4. register module (in MainActivity.java)

import com.devfd.RNGeocoder.RNGeocoderPackage; // <--- import

public class MainActivity extends ReactActivity {
  ......

  @Override
  protected List<ReactPackage> getPackages() {
    return Arrays.<ReactPackage>asList(
            new MainReactPackage(),
            new RNGeocoderPackage()); // <------ add this
  }

  ......

}

import Geocoder from 'react-native-geocoder';

// Position Geocoding
var NY = {
  lat: 40.7809261,
  lng: -73.9637594
};

Geocoder.geocodePosition(NY).then(res => {
    // res is an Array of geocoding object (see below)
})
.catch(err => console.log(err))

// Address Geocoding
Geocoder.geocodeAddress('New York').then(res => {
    // res is an Array of geocoding object (see below)
})
.catch(err => console.log(err))

Geocoding services might not be included in some Android devices (Kindle, some 4.1 devices, non-google devices). For those special cases the lib can fallback to the online google maps geocoding service

import Geocoder from 'react-native-geocoder';
// simply add your google key
Geocoder.fallbackToGoogle(MY_KEY);

// use the lib as usual
let ret = await Geocoder.geocodePosition({lat, lng})
// you get the same results

try {

    const res = await Geocoder.geocodePosition(NY);
    ...

    const res = await Geocoder.geocodeAddress('London');
    ...
}
catch(err) {
    console.log(err);
}

both iOS and Android will return the following object:

{
    position: {lat, lng},
    formattedAddress: String, // the full address
    feature: String | null, // ex Yosemite Park, Eiffel Tower
    streetNumber: String | null,
    streetName: String | null,
    postalCode: String | null,
    locality: String | null, // city name
    country: String, 
    countryCode: String
    adminArea: String | null
    subAdminArea: String | null,
    subLocality: String | null
}

iOS does not allow sending multiple geocoding requests simultaneously, unless you enable the fallbackToGoogle to handle the parallel calls when an native iOS request is active.

geocoding may not work on older android devices (4.1) and will not work if Google play services are not available.