RN Geolocation

generic-geolocation.js

/**
* @providesModule GenericGeolocation
*/

"use strict";

var Platform = require("Platform");

if (Platform.OS === "android") {
    var Manager = require("react-native").NativeModules.TruckflyGeolocationManager;

    var GenericGeolocation = {
        getCurrentPosition: function (onSuccess, onError, options) {
            Manager.getCurrentPosition(options.timeout, options.maximumAge, options.enableHighAccuracy,
                onSuccess, onError);
        },
    };
} else {
    var GenericGeolocation = require("Geolocation");
}

module.exports = GenericGeolocation;

GeolocationModule.java

package com.yourapp.rctgeolocation;

import android.location.Location;
import android.os.Bundle;
import android.util.Log;

import com.facebook.react.bridge.Callback;
import com.facebook.react.bridge.ReactApplicationContext;
import com.facebook.react.bridge.ReactContextBaseJavaModule;
import com.facebook.react.bridge.ReactMethod;
import com.facebook.react.bridge.WritableNativeMap;
import com.google.android.gms.common.ConnectionResult;
import com.google.android.gms.common.api.GoogleApiClient;
import com.google.android.gms.location.LocationServices;

/**
 * Created by corentin on 10/29/15.
 */
public class GeolocationModule extends ReactContextBaseJavaModule {
    private GoogleApiClient mGoogleApiClient;

    public GeolocationModule(ReactApplicationContext reactContext) {
        super(reactContext);
    }

    @Override
    public String getName() {
        return "TruckflyGeolocationManager";
    }

    /**
     * @param timeout
     * @param maximumAge
     * @param enableHighAccuracy true -> PRIORITY_HIGH_ACCURACY
     *                           false -> PRIORITY_BALANCED_POWER_ACCURACY
     * @param onSuccess
     * @param onError
     */
    @SuppressWarnings("unused")
    @ReactMethod
    public void getCurrentPosition(final Integer timeout,
                                   final Integer maximumAge,
                                   final Boolean enableHighAccuracy,
                                   final Callback onSuccess,
                                   final Callback onError) {
        if (onSuccess == null) {
            Log.e(getName(), "no success callback");
            return;
        }
        if (onError == null) {
            Log.e(getName(), "no error callback");
            return;
        }

        if (mGoogleApiClient == null) {
            mGoogleApiClient = new GoogleApiClient.Builder(getReactApplicationContext())
                    .addConnectionCallbacks(new GoogleApiClient.ConnectionCallbacks() {
                        @Override
                        public void onConnected(Bundle connectionHint) {
                            Log.d(getName(), "onConnected");
                            _getLastKnownLocation(onSuccess, onError, timeout,
                                    maximumAge, enableHighAccuracy);
                        }

                        @Override
                        public void onConnectionSuspended(int cause) {
                            Log.e(getName(), "onConnectionSuspended: " + cause);
                        }
                    })
                    .addOnConnectionFailedListener(new GoogleApiClient.OnConnectionFailedListener() {
                        @Override
                        public void onConnectionFailed(ConnectionResult result) {
                            Log.e(getName(), "onConnectionFailed");
                            onError.invoke();
                            mGoogleApiClient.disconnect();
                        }
                    })
                    .addApi(LocationServices.API)
                    .build();
            mGoogleApiClient.connect();
        }
        else if (mGoogleApiClient.isConnected()) {
            _getLastKnownLocation(onSuccess, onError, timeout, maximumAge, enableHighAccuracy);
        }
        else {
            mGoogleApiClient.connect();
        }
    }

    private void _getLastKnownLocation(final Callback onSuccess,
                                       final Callback onError,
                                       Integer timeout,
                                       Integer maximumAge,
                                       Boolean enableHighAccuracy) {
        Location lastLocation = LocationServices.FusedLocationApi.getLastLocation(mGoogleApiClient);
        if (lastLocation == null) {
            Log.e(getName(), "lastLocation null");
            onError.invoke();
            return;
        }

        Log.e(getName(), "lastLocation found: " + lastLocation.toString());

        WritableNativeMap result = new WritableNativeMap();
        WritableNativeMap coords = new WritableNativeMap();

        coords.putDouble("latitude", lastLocation.getLatitude());
        coords.putDouble("longitude", lastLocation.getLongitude());
        result.putMap("coords", coords);

        onSuccess.invoke(result);
    }

}

GeolocationPackage.java

package com.yourapp.rctgeolocation;

import com.facebook.react.ReactPackage;
import com.facebook.react.bridge.JavaScriptModule;
import com.facebook.react.bridge.NativeModule;
import com.facebook.react.bridge.ReactApplicationContext;
import com.facebook.react.uimanager.ViewManager;

import java.util.ArrayList;
import java.util.Collections;
import java.util.List;

/**
 * Created by corentin on 10/29/15.
 */
public class GeolocationPackage implements ReactPackage {
    @Override
    public List<NativeModule> createNativeModules(ReactApplicationContext reactContext) {
        List<NativeModule> modules = new ArrayList<>();
        modules.add(new GeolocationModule(reactContext));
        return modules;
    }

    @Override
    public List<Class<? extends JavaScriptModule>> createJSModules() {
        return Collections.emptyList();
    }

    @Override
    public List<ViewManager> createViewManagers(ReactApplicationContext reactContext) {
        return Collections.emptyList();
    }
}

You need to add the package in your MainActivity.java and add compile 'com.google.android.gms:play-services-location:8.1.0' to your app/build.gradle

Thanks man. I am trying to get it to work, but since this is my first time developing with native android code I am a bit lost.
I have started by replacing yourapp in package com.yourapp.rctgeolocation; with the actual name of my app.
Then, I have added the java files within my Android folder in the following path:

android/app/src/main/java/com/<myapp>/rtcgeolocation

And the javascript as a component within my normal javascript folder (App/Components/)

Then I added compile 'com.google.android.gms:play-services-location:8.1.0' to my build gradle.

When I require GenericGeolocation I got an error:

undefined is not an object (evaluating 'Manager.getCurrentPostion')

Coming from line 14: Manager.getCurrentPosition(...)

if I add .addPackage(new GeolocationPackage()) I get an error during the build:

MainActivity.java:29: error: cannot find symbol
                .addPackage(new GeolocationPackage())

@cosmith
I somewhat got it to work. I have managed to build the whole thing, but when calling the getCurrentLocation function I run into the following issue:

TypeError: expected dynamic type 'double', but had type 'null' ... at argument index 0

I am calling the function as follows:

GenericGeolocation.getCurrentPosition(
      20000,
      1000,
      true,
      (initialPosition) => this.setState({initialPosition}),
      (error) => console.log(error.message)
    );

I just noticed you use the argument structure of (onSuccess, onError, options). By applying it I always get the code to execute the onError callback. How can I debug the actual java code ?

P.S.: My onError is just a (error) => console.log(error) to which it prints undefined to the console

I was missing in my AndroidManifest. It works :) Awesome! How did you display a map, considering you don't have the MapView component for Android?