react-native-bluetooth-state-manager

The only purpose of this library is to manage the Bluetooth state. Not more, not less.

If you need further functionality like connecting and communicating to a device, please look at react-native-ble-plx.

Features

• Manage bluetooth state
• Open bluetooth settings page of the OS
• Declarative API

Installation

Using Yarn: (recommended)

yarn add react-native-bluetooth-state-manager

Using npm:

npm install react-native-bluetooth-state-manager --save

Linking

React-Native >= 0.60

Beginning from 0.60 you don't need to link it anymore. For more see here.

iOS

For iOS you just need to install the pods.

cd ios/
pod install
cd ..

React-Native < 0.60

Click here for instructions how to link it for react-native < 0.60

Automatic

Run react-native link react-native-bluetooth-state-manager

Manual

iOS

With cocoapods

Append the following lines to your ios/Podfile:

target '<your-project>' do
  ...
+ pod 'RNBluetoothStateManager', :path => '../node_modules/react-native-bluetooth-state-manager'
end

Without cocoapods

1. In XCode, in the project navigator, right click Libraries ➜ Add Files to [your project's name]
2. Go to node_modules ➜ react-native-bluetooth-state-manager and add RNBluetoothStateManager.xcodeproj
3. In XCode, in the project navigator, select your project. Add libRNBluetoothStateManager.a to your project's Build Phases ➜ Link Binary With Libraries
4. Run your project (Cmd+R)<

Android

Manually

1. in android/settings.gradle:

...
include ':app'
+ include ':react-native-bluetooth-state-manager'
+ project(':react-native-bluetooth-state-manager').projectDir = new File(rootProject.projectDir,   '../node_modules/react-native-bluetooth-state-manager/android')

2. in android/app/build.gradle:

dependencies {
+  compile project(':react-native-bluetooth-state-manager')
  ...
  compile "com.facebook.react:react-native:+"  // From node_modules
}

3. in android/app/src/main/java/[...]/MainApplication.java

+ import de.patwoz.rn.bluetoothstatemanager.RNBluetoothStateManagerPackage;

public class MainApplication extends Application implements ReactApplication {
  // ...

  private final ReactNativeHost mReactNativeHost = new ReactNativeHost(this) {
    @Override
    protected List<ReactPackage> getPackages() {
      return Arrays.<ReactPackage>asList(
          new MainReactPackage(),
+         new RNBluetoothStateManagerPackage()
      );
    }
  };

}

Usage

import BluetoothStateManager from 'react-native-bluetooth-state-manager';

iOS

You must provide a short description why you need access to bluetooth in your app. Otherwise your app will crash when requesting for bluetooth:

This app has crashed because it attempted to access privacy-sensitive data without a usage description.  The app's Info.plist must contain an NSBluetoothAlwaysUsageDescription key with a string value explaining to the user how the app uses this data.

See: https://developer.apple.com/documentation/bundleresources/information_property_list/nsbluetoothalwaysusagedescription

API

An example you will find in example/app/ExampleWithApi.js

Method	Return Type	OS	Description
getState()	Promise<String>	Android, iOS	Returns the current state of the bluetooth service.
onStateChange(listener, emitCurrentState)	Subscription	Android, iOS	Listen for bluetooth state changes.
openSettings()	Promise<null>	Android, iOS	Opens the bluetooth settings. Please see below for more details.
requestToEnable()	Promise<Boolean>	Android	Show a dialog that allows the user to turn on Bluetooth.
enable()	Promise<null>	Android	Enables Bluetooth without further user interaction.
disable()	Promise<null>	Android	Disables Bluetooth without further user interaction.

Important: To use enable() and disable() on android, you have to add BLUETOOTH_ADMIN permission to your AndroidManifest.xml:

  <manifest xmlns:android="http://schemas.android.com/apk/res/android">
+    <uses-permission android:name="android.permission.BLUETOOTH_ADMIN"/>
  </manifest>

---

getState()

Returns the current state of the bluetooth service.

BluetoothStateManager.getState().then((bluetoothState) => {
  switch (bluetoothState) {
    case 'Unknown':
    case 'Resetting':
    case 'Unsupported':
    case 'Unauthorized':
    case 'PoweredOff':
    case 'PoweredOn':
    default:
      break;
  }
});

onStateChange(listener, emitCurrentState)

Listen for bluetooth state changes.

BluetoothStateManager.onStateChange((bluetoothState) => {
  // do something...
}, true /*=emitCurrentState*/);

openSettings()

Android

Opens the bluetooth settings.

Tested:

• Android 6.0.1 (Huawei P8 Lite ALE-L21)
• Android 7.1.1 (Galaxy J5 2016)
• Android 8.0 (Galaxy S8+ SM-G955f)

iOS

Opens the settings page of the app. Please see here.

BluetoothStateManager.openSettings();

requestToEnable()

Show a dialog that allows the user to turn on Bluetooth. More here: Android documentation.

• This function is only on android available.

BluetoothStateManager.requestToEnable().then((result) => {
  // result === true -> user accepted to enable bluetooth
  // result === false -> user denied to enable bluetooth
});

enable()

Enables Bluetooth without further user interaction

• This function is only on android available.
• Needs the BLUETOOTH_ADMIN permission.

BluetoothStateManager.enable().then((result) => {
  // do something...
});

disable()

Disables Bluetooth without further user interaction

• This function is only on android available.

• Needs the BLUETOOTH_ADMIN permission.

BluetoothStateManager.disable().then((result) => {
  // do something...
});

EVENTS

Name	Description
EVENT_BLUETOOTH_STATE_CHANGE	Callback for when the bluetooth state changed

---

EVENT_BLUETOOTH_STATE_CHANGE

Callback for when the bluetooth state changed

BluetoothStateManager.addEventListener(
  BluetoothStateManager.EVENT_BLUETOOTH_STATE_CHANGE,
  (bluetoothState) => {
    // do something...
  }
);

// recommended: use the `onStateChange` function.

Declarative API

The declarative way uses the new context api of React 16.3.

import { BluetoothState } from 'react-native-bluetooth-state-manager';

<BluetoothState>

props

Name	Value Type	Default value	Description
emitCurrentState	Boolean	true	If true, current state will be emitted.
onChange	Function	undefined	Callback which emits the current state (first argument) change and the previous state (second argument).
children	Function or any	undefined

<BluetoothState.PoweredOn>

The children prop of this component will rendered only when bluetooth is turned on.

<BluetoothState.PoweredOff>

The children prop of this component will rendered only when bluetooth is turned off.

<BluetoothState.Resetting>

The children prop of this component will rendered only when bluetooth state is changing.

• "PoweredOff" -> "PoweredOn"
• "PoweredOn" -> "PoweredOff"

<BluetoothState.Unauthorized>

The children prop of this component will rendered only when the app doesn't have the permission to use bluetooth.

<BluetoothState.Unsupported>

The children prop of this component will rendered only when the device doesn't support bluetooth.

<BluetoothState.Unknown>

The children prop of this component will rendered only when the bluetooth state is unknown.

---

BluetoothState

An example you will find in example/app/ExampleWithDeclarativeApi.js

Context

Each component has access to the same context as shown below.

{
  bluetoothState: String,
  openSettings: Function,
  requestToEnable: Function,
  enable: Function,
  disable: Function,
}

children prop as function:

<BluetoothState>
  {({ bluetoothState, openSettings, requestToEnable, enable, disable }) => {
    // show something ...
    return <View />;
  }}
</BluetoothState>

BluetoothState.<BluetoothStateType>

Example

import { BluetoothState } from 'react-native-bluetooth-state-manager';

<BluetoothState>
  <BluetoothState.PoweredOn>
    <Text>This will rendered only when bluetooth is turned on.</Text>
  </BluetoothState.PoweredOn>
  <BluetoothState.PoweredOff>
    {({ requestToEnable, openSettings }) => (
      <View>
        <Text>This will rendered only when bluetooth is turned off.</Text>
        <Button
          title="This will rendered only when bluetooth is turned off."
          onPress={Platform.OS === 'android' ? requestToEnable : openSettings}
        />
      </View>
    )}
  </BluetoothState.PoweredOff>
  <BluetoothState.Resetting>
    <ActivityIndicator />
  </BluetoothState.Resetting>
  <BluetoothState.Unauthorized>
    <Text>This will rendered only when bluetooth permission is not granted.</Text>
  </BluetoothState.Unauthorized>
  <BluetoothState.Unsupported>
    <Text>This will rendered only when bluetooth is not supported.</Text>
  </BluetoothState.Unsupported>
  <BluetoothState.Unknown>
    <Text>You have a really strange phone.</Text>
  </BluetoothState.Unknown>
</BluetoothState>;

ToDo's

• Add tests

Why?

Why not just using react-native-ble-plx?

Because it's to over bloated for my purpose. In several of my projects I'm working on, I had to integrate several third-party SDK which communicates with different bluetooth devices (on the native side). So the only functionality I needed there (on the javascript side), was to check if the bluetooth is enabled to start the third-party SDK.

License

MIT