Native GPS location support for React Native.

Install using npm with npm install --save react-native-location

You then need to add the Objective C part to your XCode project. Drag RNLocation.xcodeproj from the node_modules/react-native-location folder into your XCode project. Click on the your project in XCode, goto Build Phases then Link Binary With Libraries and add libRNLocation.a and CoreLocation.framework.

NOTE: Make sure you don't have the RNLocation project open separately in XCode otherwise it won't work.

var React = require('react-native');
var { DeviceEventEmitter } = React;

var { RNLocation: Location } = require('NativeModules');

Location.requestAlwaysAuthorization();
Location.startUpdatingLocation();
Location.setDistanceFilter(5.0);

var subscription = DeviceEventEmitter.addListener(
    'locationUpdated',
    (location) => {
        /* Example location returned
        {
          coords: {
            speed: -1,
            longitude: -0.1337,
            latitude: 51.50998,
            accuracy: 5,
            heading: -1,
            altitude: 0,
            altitudeAccuracy: -1
          },
          timestamp: 1446007304457.029
        }
        */
    }
);

var React = require('react-native');
var { DeviceEventEmitter } = React;

var { RNLocation: Location } = require('NativeModules');
Location.requestAlwaysAuthorization();
Location.startUpdatingHeading();

DeviceEventEmitter.addListener(
    'headingUpdated',
    (data) => {
        /* Example data returned
        {
          heading: 57.2839832
        }
        */
    }
);

It is recommended to set NSWhenInUseUsageDescription in your Info.plist file.

For background mode to work, a few things need to be configured:

1. In the Xcode project, go to Capabilities, switch on "Background Modes" and check "Location updates".
2. Using requestAlwaysAuthorization in place of requestWhenInUseAuthorization:

Location.requestAlwaysAuthorization();

3. Set NSLocationAlwaysUsageDescription in your Info.plist file.

To access the methods, you need import the react-native-location module. This is done through var Beacons = require('react-native-location').

Location.requestWhenInUseAuthorization();

This method should be called before anything else. It requests location updates while the application is open. If the application is in the background, you will not get location updates. Either this method or Location.requestAlwaysAuthorization (but not both) needs to be called to receive updates.

Location.requestAlwaysAuthorization();

This method should be called before anything else is called. It requests location updates while the application is open or in the background. Either this method or Location.requestWhenInUseAuthorization (but not both) needs to be called to receive updates.

Location.getAuthorizationStatus(function(authorization) {
  // authorization is a string which is either "authorizedAlways",
  // "authorizedWhenInUse", "denied", "notDetermined" or "restricted"
});

This methods gets the current authorization status. While this methods provides a callback, it is not executed asynchronously. The values authorizedAlways and authorizedWhenInUse correspond to the methods requestWhenInUseAuthorization and requestAlwaysAuthorization respectively.

Location.setDesiredAccuracy(distanceInMeters);

Set the desired accuracy of location updates in meters. Determines the method used to obtain location updates. Low values will trigger using GPS.

Location.setDistanceFilter(distanceInMeters);

Set the desired minimum distance between location updates in meters.

Location.startMonitoringSignificantLocationChanges();

Location.startUpdatingLocation();
var subscription = DeviceEventEmitter.addListener(
    'locationUpdated',
    (location) => {
        // do something with the location
    }
);

Start signifcant location updates (typically using network sources like Wifi/Cellular and with a minimum time gap of 5 minutes). Your application will be called back with location updates via the DeviceEventEmitter event 'locationUpdated'.

Location.startUpdatingLocation();
var subscription = DeviceEventEmitter.addListener(
    'locationUpdated',
    (location) => {
        // do something with the location
    }
);

Start location updates. Your application will be called back with location updates that meet any mininum distance requirements that you specify via the DeviceEventEmitter event 'locationUpdated'.

Location.startUpdatingHeading();
var subscription = DeviceEventEmitter.addListener(
    'headingUpdated',
    (data) => {
        // do something with the heading
    }
);

Start heading updates. Your application will be called back with heading updates.

Location.stopUpdatingLocation();

Stop receiving location events.

Location.stopUpdatingHeading();

Stop receiving heading events.

Location.stopMonitoringSignificantLocationChanges();

Stop receiving sigificant location change events.

To listen to events we need to call DeviceEventEmitter.addListener (var {DeviceEventEmitter} = require('react-native')) where the first parameter is the event we want to listen to and the second is a callback function that will be called once the event is triggered.

Received when a location update has been sensed by the system. The event delivers one parameter, location, that is an object with location, elevation, and accuracy data.

Received when the heading changes. The event delivers one parameter: an object with the current heading in degrees.

MIT, for more information see LICENSE