React Native Voice

A speech-to-text library for React Native.

npm i @react-native-community/voice --save

Table of contents

• Linking
  • Manually Link Android
  • Manually Link iOS
• Usage
  • Example
• API
• Events
• Permissions
  • Android
  • iOS
• Contributors

Linking

Manually or automatically link the NativeModule

react-native link @react-native-community/voice

Manually Link Android

• In android/setting.gradle

...
include ':@react-native-community_voice', ':app'
project(':@react-native-community_voice').projectDir = new File(rootProject.projectDir, '../node_modules/@react-native-community/voice/android')

• In android/app/build.gradle

...
dependencies {
    ...
    compile project(':@react-native-community_voice')
}

• In MainApplication.java

import android.app.Application;
import com.facebook.react.ReactApplication;
import com.facebook.react.ReactPackage;
...
import com.wenkesj.voice.VoicePackage; // <------ Add this!
...

public class MainActivity extends Activity implements ReactApplication {
...
    @Override
    protected List<ReactPackage> getPackages() {
      return Arrays.<ReactPackage>asList(
        new MainReactPackage(),
        new VoicePackage() // <------ Add this!
        );
    }
}

Manually Link iOS

• Drag the Voice.xcodeproj from the @react-native-community/voice/ios folder to the Libraries group on Xcode in your poject. Manual linking

• Click on your main project file (the one that represents the .xcodeproj) select Build Phases and drag the static library, lib.Voice.a, from the Libraries/Voice.xcodeproj/Products folder to Link Binary With Libraries

Usage

Full example for Android and iOS.

Example

import Voice from '@react-native-community/voice';
import React, {Component} from 'react';

class VoiceTest extends Component {
  constructor(props) {
    Voice.onSpeechStart = this.onSpeechStartHandler.bind(this);
    Voice.onSpeechEnd = this.onSpeechEndHandler.bind(this);
    Voice.onSpeechResults = this.onSpeechResultsHandler.bind(this);
  }
  onStartButtonPress(e){
    Voice.start('en-US');
  }
  ...
}

API

Static access to the Voice API.

All methods now return a new Promise for async/await compatibility.

Method Name	Description	Platform
Voice.isAvailable()	Checks whether a speech recognition service is available on the system.	Android, iOS
Voice.start(locale)	Starts listening for speech for a specific locale. Returns null if no error occurs.	Android, iOS
Voice.stop()	Stops listening for speech. Returns null if no error occurs.	Android, iOS
Voice.cancel()	Cancels the speech recognition. Returns null if no error occurs.	Android, iOS
Voice.destroy()	Destroys the current SpeechRecognizer instance. Returns null if no error occurs.	Android, iOS
Voice.removeAllListeners()	Cleans/nullifies overridden Voice static methods.	Android, iOS
Voice.isRecognizing()	Return if the SpeechRecognizer is recognizing.	Android, iOS
Voice.getSpeechRecognitionServices()	Returns a list of the speech recognition engines available on the device. (Example: ['com.google.android.googlequicksearchbox'] if Google is the only one available.)	Android

Events

Callbacks that are invoked when a native event emitted.

Event Name	Description	Event	Platform
Voice.onSpeechStart(event)	Invoked when .start() is called without error.	{ error: false }	Android, iOS
Voice.onSpeechRecognized(event)	Invoked when speech is recognized.	{ error: false }	Android, iOS
Voice.onSpeechEnd(event)	Invoked when SpeechRecognizer stops recognition.	{ error: false }	Android, iOS
Voice.onSpeechError(event)	Invoked when an error occurs.	{ error: Description of error as string }	Android, iOS
Voice.onSpeechResults(event)	Invoked when SpeechRecognizer is finished recognizing.	{ value: [..., 'Speech recognized'] }	Android, iOS
Voice.onSpeechPartialResults(event)	Invoked when any results are computed.	{ value: [..., 'Partial speech recognized'] }	Android, iOS
Voice.onSpeechVolumeChanged(event)	Invoked when pitch that is recognized changed.	{ value: pitch in dB }	Android

Permissions

Arguably the most important part.

Android

While the included VoiceTest app works without explicit permissions checks and requests, it may be necessary to add a permission request for RECORD_AUDIO for some configurations. Since Android M (6.0), user need to grant permission at runtime (and not during app installation). By default, calling the startSpeech method will invoke RECORD AUDIO permission popup to the user. This can be disabled by passing REQUEST_PERMISSIONS_AUTO: true in the options argument.

If you're running an ejected expo/expokit app, you may run into issues with permissions on Android and get the following error host.exp.exponent.MainActivity cannot be cast to com.facebook.react.ReactActivity startSpeech. This can be resolved by prompting for permssion using the expo-permission package before starting recognition.

import { Permissions } from "expo";
async componentDidMount() {
	const { status, expires, permissions } = await Permissions.askAsync(
		Permissions.AUDIO_RECORDING
	);
	if (status !== "granted") {
		//Permissions not granted. Don't show the start recording button because it will cause problems if it's pressed.
		this.setState({showRecordButton: false});
	} else {
		this.setState({showRecordButton: true});
	}
}

iOS

Need to include permissions for NSMicrophoneUsageDescription and NSSpeechRecognitionUsageDescription inside Info.plist for iOS. See the included VoiceTest for how to handle these cases.

<dict>
  ...
  <key>NSMicrophoneUsageDescription</key>
  <string>Description of why you require the use of the microphone</string>
  <key>NSSpeechRecognitionUsageDescription</key>
  <string>Description of why you require the use of the speech recognition</string>
  ...
</dict>

Please see the documentation provided by ReactNative for this: PermissionsAndroid

Contributors

• @asafron
• @BrendanFDMoore
• @brudny
• @chitezh
• @ifsnow
• @jamsch
• @misino
• @Noitidart
• @ohtangza & @hayanmind
• @rudiedev6
• @tdonia
• @wenkesj