Some improvements

README.md

@@ -1,6 +1,6 @@
 
 
-# react-native-geocoder 
+# react-native-geocoder
 
 [![CircleCI](https://circleci.com/gh/devfd/react-native-geocoder/tree/master.svg?style=shield)](https://circleci.com/gh/devfd/react-native-geocoder/tree/master)
 
@@ -114,13 +114,17 @@ both iOS and Android will return the following object:
 ```js
 {
     position: {lat, lng},
+    region: {
+      center: {lat, lng},
+      radius: Number,
+    } | null,
     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, 
+    country: String,
     countryCode: String
     adminArea: String | null
     subAdminArea: String | null,
@@ -135,5 +139,4 @@ iOS does not allow sending multiple geocoding requests simultaneously, unless yo
 
 ### Android
 geocoding may not work on older android devices (4.1) and will not work if Google play services are not available.
-
-
+`region` will always be `null` on Android since it doesn't support the feature. In this case, `Geocoder.geocodePositionFallback` and `Geocoder.geocodeAddressFallback` may be used to get the `region` value.

android/src/main/java/com/devfd/RNGeocoder/RNGeocoderModule.java

@@ -1,8 +1,10 @@
 package com.devfd.RNGeocoder;
 
+import android.content.Context;
 import android.location.Address;
 import android.location.Geocoder;
 
+import com.facebook.react.bridge.Callback;
 import com.facebook.react.bridge.Promise;
 import com.facebook.react.bridge.ReactApplicationContext;
 import com.facebook.react.bridge.ReactContextBaseJavaModule;
@@ -15,21 +17,41 @@
 
 import java.io.IOException;
 import java.util.List;
+import java.util.Locale;
 
 public class RNGeocoderModule extends ReactContextBaseJavaModule {
 
+    private Context context;
+    private Locale locale;
     private Geocoder geocoder;
 
     public RNGeocoderModule(ReactApplicationContext reactContext) {
         super(reactContext);
-        geocoder = new Geocoder(reactContext.getApplicationContext());
+        context = reactContext.getApplicationContext();
+
+        locale = context.getResources().getConfiguration().locale;
+        geocoder = new Geocoder(context, locale);
     }
 
     @Override
     public String getName() {
         return "RNGeocoder";
     }
 
+    @ReactMethod
+    public void setLanguage(String language, Callback callback) {
+        Locale target = new Locale(language);
+        if (!context.getResources().getConfiguration().locale.equals(target) && !locale.equals(target)) {
+          locale = target;
+          geocoder = new Geocoder(context, locale);
+
+          callback.invoke(language);
+          return;
+        }
+
+        callback.invoke((String) null);
+    }
+
     @ReactMethod
     public void geocodeAddress(String addressName, Promise promise) {
         if (!geocoder.isPresent()) {
@@ -39,7 +61,12 @@ public void geocodeAddress(String addressName, Promise promise) {
 
         try {
             List<Address> addresses = geocoder.getFromLocationName(addressName, 20);
-            promise.resolve(transform(addresses));
+            if(addresses != null && addresses.size() > 0) {
+                promise.resolve(transform(addresses));
+            } else {
+                promise.reject("NOT_AVAILABLE", "Geocoder returned an empty list");
+            }
+
         }
 
         catch (IOException e) {
@@ -74,6 +101,9 @@ WritableArray transform(List<Address> addresses) {
             position.putDouble("lng", address.getLongitude());
             result.putMap("position", position);
 
+            // There is no region field in the `Address` object.
+            result.putString("region", null);
+
             final String feature_name = address.getFeatureName();
             if (feature_name != null && !feature_name.equals(address.getSubThoroughfare()) &&
                     !feature_name.equals(address.getThoroughfare()) &&

ios/RNGeocoder/RNGeocoder.h

@@ -1,5 +1,5 @@
-#import "RCTBridgeModule.h"
-#import "RCTConvert.h"
+#import <React/RCTBridgeModule.h>
+#import <React/RCTConvert.h>
 
 #import <CoreLocation/CoreLocation.h>
 

ios/RNGeocoder/RNGeocoder.m

@@ -2,7 +2,7 @@
 
 #import <CoreLocation/CoreLocation.h>
 
-#import "RCTConvert.h"
+#import <React/RCTConvert.h>
 
 @implementation RCTConvert (CoreLocation)
 
@@ -22,6 +22,17 @@ @implementation RNGeocoder
 
 RCT_EXPORT_MODULE();
 
+RCT_EXPORT_METHOD(setLanguage:(NSString *)language
+                  callback:(RCTResponseSenderBlock)callback)
+{
+  NSString *deviceLanguage = [[NSLocale preferredLanguages] objectAtIndex:0];
+  if ([deviceLanguage isEqualToString:language]) {
+    return callback(@[[NSNull null]]);
+  }
+
+  callback(@[language]);
+}
+
 RCT_EXPORT_METHOD(geocodePosition:(CLLocation *)location
                   resolver:(RCTPromiseResolveBlock)resolve
                   rejecter:(RCTPromiseRejectBlock)reject)
@@ -81,6 +92,7 @@ - (NSArray *)placemarksToDictionary:(NSArray *)placemarks {
 
   for (int i = 0; i < placemarks.count; i++) {
     CLPlacemark* placemark = [placemarks objectAtIndex:i];
+    CLCircularRegion* region = placemark.region;
 
     NSString* name = [NSNull null];
 
@@ -100,6 +112,13 @@ - (NSArray *)placemarksToDictionary:(NSArray *)placemarks {
          @"lat": [NSNumber numberWithDouble:placemark.location.coordinate.latitude],
          @"lng": [NSNumber numberWithDouble:placemark.location.coordinate.longitude],
          },
+     @"region": placemark.region ? @{
+         @"center": @{
+             @"lat": [NSNumber numberWithDouble:region.center.latitude],
+             @"lng": [NSNumber numberWithDouble:region.center.longitude],
+             },
+         @"radius": [NSNumber numberWithDouble:region.radius],
+         } : [NSNull null],
      @"country": placemark.country ?: [NSNull null],
      @"countryCode": placemark.ISOcountryCode ?: [NSNull null],
      @"locality": placemark.locality ?: [NSNull null],
@@ -109,7 +128,7 @@ - (NSArray *)placemarksToDictionary:(NSArray *)placemarks {
      @"postalCode": placemark.postalCode ?: [NSNull null],
      @"adminArea": placemark.administrativeArea ?: [NSNull null],
      @"subAdminArea": placemark.subAdministrativeArea ?: [NSNull null],
-     @"formattedAddress": [lines componentsJoinedByString:@", "]
+     @"formattedAddress": [lines componentsJoinedByString:@", "],
    };
 
     [results addObject:result];

js/geocoder.js

@@ -1,23 +1,46 @@
-import { NativeModules } from 'react-native';
+import { NativeModules, Platform } from 'react-native';
 import GoogleApi from './googleApi.js';
 
 const { RNGeocoder } = NativeModules;
 
 export default {
   apiKey: null,
+  language: null,
 
   fallbackToGoogle(key) {
     this.apiKey = key;
   },
 
+  setLanguage(language) {
+    RNGeocoder.setLanguage(language, (result) => {
+      this.language = result;
+    });
+  },
+
+  geocodePositionFallback(position) {
+    if (!this.apiKey) { throw new Error("Google API key required"); }
+
+    return GoogleApi.geocodePosition(this.apiKey, position, this.language);
+  },
+
+  geocodeAddressFallback(address) {
+    if (!this.apiKey) { throw new Error("Google API key required"); }
+
+    return GoogleApi.geocodeAddress(this.apiKey, address, this.language);
+  },
+
   geocodePosition(position) {
     if (!position || !position.lat || !position.lng) {
       return Promise.reject(new Error("invalid position: {lat, lng} required"));
     }
 
+    if (this.language && (Platform.OS === 'ios')) {
+      return this.geocodePositionFallback(position);
+    }
+
     return RNGeocoder.geocodePosition(position).catch(err => {
-      if (!this.apiKey || err.code !== 'NOT_AVAILABLE') { throw err; }
-      return GoogleApi.geocodePosition(this.apiKey, position);
+      if (err.code !== 'NOT_AVAILABLE') { throw err; }
+      return this.geocodePositionFallback(position);
     });
   },
 
@@ -26,9 +49,13 @@ export default {
       return Promise.reject(new Error("address is null"));
     }
 
+    if (this.language && (Platform.OS === 'ios')) {
+      return this.geocodeAddressFallback(address);
+    }
+
     return RNGeocoder.geocodeAddress(address).catch(err => {
-      if (!this.apiKey || err.code !== 'NOT_AVAILABLE') { throw err; }
-      return GoogleApi.geocodeAddress(this.apiKey, address);
+      if (err.code !== 'NOT_AVAILABLE') { throw err; }
+      return this.geocodeAddressFallback(address);
     });
   },
 }