iBeacon support for React Native. The API is very similar to the CoreLocation Objective-C one with the only major difference that regions are plain JavaScript objects. Beacons don't work in the iOS simulator.
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This module supports all iBeacon-compatible devices. Personally, I had the best experience with Estimote beacons, but all devices that support the iBeacon specification should work.
Install using npm with npm install --save react-native-ibeacon. React Native >=0.4.0 is needed.
You then need to add the Objective C part to your XCode project. Drag RNBeacon.xcodeproj from the node_modules/react-native-ibeacon folder into your XCode project. Click on the your project in XCode, goto Build Phases then Link Binary With Libraries and add libRNBeacon.a and CoreLocation.framework.
NOTE: Make sure you don't have the RNBeacon project open separately in XCode otherwise it won't work.
var React = require('react-native');
var {DeviceEventEmitter} = React;
var Beacons = require('react-native-ibeacon');
// Define a region which can be identifier + uuid,
// identifier + uuid + major or identifier + uuid + major + minor
// (minor and major properties are numbers)
var region = {
identifier: 'Estimotes',
uuid: 'B9407F30-F5F8-466E-AFF9-25556B57FE6D'
};
// Request for authorization while the app is open
Beacons.requestWhenInUseAuthorization();
Beacons.startMonitoringForRegion(region);
Beacons.startRangingBeaconsInRegion(region);
Beacons.startUpdatingLocation();
// Listen for beacon changes
var subscription = DeviceEventEmitter.addListener(
'beaconsDidRange',
(data) => {
// data.region - The current region
// data.region.identifier
// data.region.uuid
// data.beacons - Array of all beacons inside a region
// in the following structure:
// .uuid
// .major - The major version of a beacon
// .minor - The minor version of a beacon
// .rssi - Signal strength: RSSI value (between -100 and 0)
// .proximity - Proximity value, can either be "unknown", "far", "near" or "immediate"
// .accuracy - The accuracy of a beacon
}
);It is recommended to set NSLocationWhenInUseUsageDescription in your Info.plist file.
For background mode to work, a few things need to be configured: In the Xcode project, go to Capabilities, switch on "Background Modes" and check both "Location updates" and "Uses Bluetooth LE accessories".
Then, instead of using requestWhenInUseAuthorization the method requestAlwaysAuthorization.
Beacons.requestAlwaysAuthorization();Here, it's also recommended to set NSLocationAlwaysUsageDescription in your Info.plist file.
Finally when killed or sleeping and a beacon is found your whole app wont be loaded, just the didFinishLaunchingWithOptions:(NSDictionary *)launchOptions delegate so you need to act on it there like:
// a region we were scanning for has appeared, ask to open us
if([launchOptions objectForKey:@"UIApplicationLaunchOptionsLocationKey"])
{
//pop a notification to ask user to open, or maybe reload your scanner with delegate so that code fires
}
To access the methods, you need import the react-native-ibeacon module. This is done through var Beacons = require('react-native-ibeacon').
Beacons.requestWhenInUseAuthorization();This method should be called before anything else is called. It handles to request the use of beacons while the application is open. If the application is in the background, you will not get a signal from beacons. Either this method or Beacons.requestAlwaysAuthorization needs to be called to receive data from beacons.
Beacons.requestAlwaysAuthorization();This method should be called before anything else is called. It handles to request the use of beacons while the application is open or in the background. Either this method or Beacons.requestWhenInUseAuthorization needs to be called to receive data from beacons.
Beacons.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.
var region = {
identifier: 'Estimotes',
uuid: 'B9407F30-F5F8-466E-AFF9-25556B57FE6D'
};
Beacons.startMonitoringForRegion(region);When starting monitoring for beacons, we need to define a region as the parameter. The region is an object, which needs to have at least two values: identifier and uuid. Additionally, it can also have a major, minor version or both. Make sure to not re-use the same identifier. In that case, we won't get the data for the beacons. The corresponding events are regionDidEnter and regionDidExit.
var region = {
identifier: 'Estimotes',
uuid: 'B9407F30-F5F8-466E-AFF9-25556B57FE6D'
};
Beacons.startRangingBeaconsInRegion(region);When ranging for beacons, we need to define a region as the parameter. The region is an object, which needs to have at least two values: identifier and uuid. Additionally, it can also have a major, minor version or both. Make sure to not re-use the same identifier. In that case, we won't get the data for the beacons. The corresponding events are beaconsDidRange. The event will fire in every interval the beacon sends a signal, which is one second in most cases.
If we are monitoring and ranging for beacons, it is best to first call startMonitoringForRegion and then call startRangingBeaconsInRegion.
Beacons.startUpdatingLocation();This call is needed for monitoring beacons and gets the initial position of the device.
Beacons.stopUpdatingLocation();This method should be called when you don't need to receive location-based information and want to save battery power.
Beacons.shouldDropEmptyRanges(true);Call this method to stop sending the beaconsDidRange event when the beacon list is empty. This can be useful when listening to multiple beacon regions and can reduce cpu usage by 1-1.5%.
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.
This event will be called for every region in every beacon interval. If you have three regions you get three events every second (which is the default interval beacons send their signal). When we take a closer look at the parameter of the callback, we get information on both the region and the beacons.
{
region: {
identifier: String,
uuid: String
},
beacons: Array<Beacon>
}A Beacon is an object that follows this structure:
{
uuid: String, // The uuid for the beacon
major: Number, // A beacon's major value
minor: Number, // A beacon's minor value
rssi: Number, // The signal strength, where -100 is the maximum value and 0 the minium.
// If the value is 0, this corresponds to not being able to get a precise value
proximity: String, // Fuzzy value representation of the signal strength.
// Can either be "far", "near", "immediate" or "unknown"
accuracy: Number // One sigma horizontal accuracy in meters, see: http://stackoverflow.com/questions/20416218/understanding-ibeacon-distancing/30174335#30174335
}By default, the array is sorted by the rssi value of the beacons.
If the device entered a region, regionDidEnter is being called.
Inside the callback the paramter we can use returns an object with a property region that contains the region identifier value as a string. Additionally, we get the UUID of the region through its uuid property.
{
region: String,
uuid: String
}In the same regionDidEnter is called if the device entered a region, regionDidExit will be called if the device exited a region and we can't get any signal from any of the beacons inside the region.
As for the payload, we get a property called region that represents the region identifier and is a string as well as the uuid.
{
region: String,
uuid: String
}###authorizationDidChange When the user permissions change, for example the user allows to always use beacons, this event will be called. The same applies when the user revokes the permission to use beacons.
// The payload is a string which can either be:
// "authorizedAlways", "authorizedWhenInUse", "denied", "notDetermined" or "restricted"There are several things that trigger that behavior, so it's best to follow these steps:
- Don't use the same identifier for multiple regions
- Check if your beacon batteries aren't empty
- If monitoring and ranging for beacons, make sure to first monitor and then range
This repository uses the Geniux code style guide (based on the AirBnB style guide), for more information see: https://github.com/geniuxconsulting/javascript
For commit messages, we are following the commit guide from https://github.com/geniuxconsulting/guideline
MIT, for more information see LICENSE
See CHANGELOG.md