README.md

react-native-location

Native GPS location support for React Native.

You might decide to use this library over the built-in geolocation because it includes some additional features:

• Allows you choose what type of permission to ask for ("when in use" or "always"). The built-in geolocation library will look at your plist file and choose "always" if you have the NSLocationAlwaysUsageDescription property, however, you might have a usecase where you want to start by asking the user for "while in use" permission and later upgrade the permission to "always" when they turn on a feature which requires background location.
• Ability to check the current permission status (RNLocation.getCurrentPermission).
• Allows you to monitor the device heading.

This is a prerelease version of the library which changes the API and adds Android support. For the previous version, please see the master branch.

Installation

Install the library using either Yarn:

yarn add react-native-location

or using npm:

npm install --save react-native-location

You then need to link the native parts of the library:

react-native link react-native-location

You then need to open XCode, go to the project settings and ensure that CoreLocation.framework is added to the Link Binary With Libraries section.

Alternatively, you can do a manual installation with XCode. First, drag node_modules/react-native-location/ios/RNLocation.xcodeproj into your XCode project. Click on the your project in XCode (the name of your project at the top of the left panel), go to Build Phases then Link Binary With Libraries and add libRNLocation.a and CoreLocation.framework.

Finally, you then need to make sure you have the correct permissions inside your info.plist file. React Native automatically sets up the PList config key for NSLocationWhenInUseUsageDescription. However, to use always permission you will need to add NSLocationAlwaysAndWhenInUseUsageDescription and NSLocationAlwaysUsageDescription into your PList file. The string message in the key will show in the Alert box when your app requests permissions. To start, you can simply add these to your file and edit them (or remove them) later. Remember to only request the permissions you NEED within your app. See the detail on Background Mode later on.

<key>NSLocationWhenInUseUsageDescription</key>
<string>This is the plist item for NSLocationWhenInUseUsageDescription</string>
<key>NSLocationAlwaysAndWhenInUseUsageDescription</key>
<string>This is the plist item for NSLocationAlwaysAndWhenInUseUsageDescription</string>
<key>NSLocationAlwaysUsageDescription</key>
<string>This is the plist item for NSLocationAlwaysUsageDescription</string>

For Android, you need to ensure that your AndroidManifest.xml contains this line:

<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION"/>

If you want to access fine location then you should also include:

<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"/>

Background mode setup (optional)

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. Set NSLocationAlwaysAndWhenInUseUsageDescription and NSLocationAlwaysUsageDescription in your Info.plist file.
3. For iOS 9+, set allowsBackgroundLocationUpdates to true, like this:

RNLocation.configure({ allowsBackgroundLocationUpdates: true });

Example application

In the example folder is a React Native sample app which simply allows you to test out whether the library is working for you. You can also use this as a sample implementation to start from. The app requests always on permissions, takes reading every 5 distance and starts immediately. To utilize in the simulator, look on the Debug -> Location menu for optional sample trips that will show you updating location such as City Bicicle Ride, City Run and Freeway Drive.

Usage

import RNLocation from 'react-native-location';

RNLocation.configure({
  distanceFilter: 5.0
})

RNLocation.requestPermission({
  ios: "whenInUse",
  android: {
    detail: "coarse"
  }
}).then(granted => {
    if (granted) {
      this.locationSubscription = RNLocation.subscribeToLocationUpdates(locations => {
        /* Example location returned
        {
          speed: -1,
          longitude: -0.1337,
          latitude: 51.50998,
          accuracy: 5,
          heading: -1,
          altitude: 0,
          altitudeAccuracy: -1
          floor: 0
          timestamp: 1446007304457.029
        }
        */
      })
    }
  })

Methods

To access the methods, you need import the react-native-location module. This is done through import RNLocation from 'react-native-location'.

Configuration

RNLocation.configure

This is used to configure the location provider. You can use this to enable background mode, filter location updates to a certain distance change, and ensure you have the power settings set correctly for your use case.

You can call configure multiple times at it will only change the setting which you pass to it. For example if you only want to change activityType, you can call configure with just that property present.

RNLocation.configure({
    distanceFilter: 100, // Meters
    desiredAccuracy: {
      ios: "best",
      android: "balancedPowerAccuracy"
    },
    // iOS Only
    activityType: "other",
    allowsBackgroundLocationUpdates: false,
    headingFilter: 1, // Degrees
    headingOrientation: "portrait",
    pausesLocationUpdatesAutomatically: false,
    showsBackgroundLocationIndicator: false,
})

Permissions

Correctly managing permissions is key to working with the users location in mobile apps.

• Ask for the lowest level of permissions you can. You'll almost always only need whenInUse (foreground) permission rather than background.
• On iOS you only get one chance to ask for permission. If the user requests it the first time this method will always resolves to false.
• If you ask for always permission then the user gets the chance to accept, but only give you whenInUse permission. The Promise will still resolve to false, however, if you call RNLocation.getCurrentPermission you can check if they actually accepted the lesser permission.
• You should monitor the permissions and respond to it correctly. The user is able to go to their phone setting and revoke or downgrade permissions at any time.

RNLocation.requestPermission

This method should be called before subscribing to location updates. You need to pass in the type of permission you want for each platform. You can choose not to ignore a platform and it will be ignored. The method returns a promise which resolves to true if the permission was granted and false if not. For Android you can optionally provide a rationale which will be displayed if you ask the user for permission a 2nd time after they have denied permission once.

RNLocation.requestPermission({
  ios: 'whenInUse', // or 'always'
  android: {
    detail: 'coarse', // or 'fine'
    rationale: {
      title: "We need to access your location",
      message: "We use your location to show where you are on the map",
      buttonPositive: "OK",
      buttonNegative: "Cancel"
    }
  }
});

RNLocation.checkPermission

Checks if the currently granted permissions match the given options. You can call this before requestPermission to check if you already have the permission level you would like. This is especially useful if you want to display a message to the user about not having the correct permissions before actually requesting them.

RNLocation.checkPermission({
  ios: 'whenInUse', // or 'always'
  android: {
    detail: 'coarse' // or 'fine'
  }
});

RNLocation.getCurrentPermission

Gets the current permission status.

RNLocation.getCurrentPermission()
  .then(currentPermission => {
    ...
  })

RNLocation.subscribeToPermissionUpdates

Monitor the permission status for changes.

// Subscribe
const unsubscribe = RNLocation.subscribeToPermissionUpdates(currentPermission => {
  ...
})

// Unsubscribe
unsubscribe();

RNLocation.subscribeToLocationUpdates

Subscribe to location changes with the given listener. Ensure you have the correct permission before calling this method. The location provider will respect the settings you have given it. Each event may return an array with more than one location. This is because the OS might batch location updates together and deliver them all at once. Take a look at the timestamp to find the latest.

// Subscribe
const unsubscribe = RNLocation.subscribeToLocationUpdates(locations => {
  ...
})

// Unsubscribe
unsubscribe();

RNLocation.subscribeToSignificantLocationUpdates (iOS only)

Subscribe to significant updates to the users location with the given listener. This method does not take into account the distanceFilter which you configured RNLocation with. In most cases, you should call RNLocation.configure with the correct settings and then use RNLocation.subscribeToLocationUpdates to subscribe to the location updates. This will allow you to support both Android and iOS with the same code. For more details, take a look at Apple's documentation.

// Subscribe
const unsubscribe = RNLocation.subscribeToSignificantLocationUpdates(locations => {
  ...
})

// Unsubscribe
unsubscribe();

RNLocation.subscribeToHeadingUpdates (iOS only)

Subscribe to heading changes with the given listener. Ensure you have the correct permission before calling this method. The location provider will respect the settings you have given it.

// Subscribe
const unsubscribe = RNLocation.subscribeToHeadingUpdates(heading => {
  ...
})

// Unsubscribe
unsubscribe();

License

The library is released under the MIT licence. For more information see LICENSE.