react-native-qrcode-scanner

A QR code scanner component for React Native built on top of react-native-camera by Lochlan Wansbrough

Please note, this will also function as a generic barcode scanner by the virtue of the above module supporting barcode scanning, however, this module was initially built as a QR code scanner.

I wrote this module because I couldn't find one that could be simply plugged into a project without requiring too much setup.

Getting started

Requirements

iOS 10

With iOS 10 and higher you need to add the "Privacy - Camera Usage Description" key to the info.plist of your project. This should be found in 'your_project/ios/your_project/Info.plist'. Add the following code:

<key>NSCameraUsageDescription</key>
<string>Your message to user when the camera is accessed for the first time</string>

<!-- Include this only if you are planning to use the camera roll -->
<key>NSPhotoLibraryUsageDescription</key>
<string>Your message to user when the photo library is accessed for the first time</string>

<!-- Include this only if you are planning to use the microphone for video recording -->
<key>NSMicrophoneUsageDescription</key>
<string>Your message to user when the microsphone is accessed for the first time</string>

Android 7

With Android 7 and higher you need to add the "Vibration" permission to your AndroidManifest.xml of your project. This should be found in your android/app/src/main/AndroidManifest.xml Add the following:

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

react-native-camera

react-native-camera is a dependency for this package that you'll need to add to your project. To install, run the following commands:

1. npm install react-native-camera --save
2. react-native link react-native-camera

To install and start using react-native-qrcode-scanner:

npm install react-native-qrcode-scanner --save

react-native link react-native-qrcode-scanner

Usage

To use react-native-qrcode-scanner, import the react-native-qrcode-scanner module and use the <QRCodeScanner /> tag. More usage examples can be seen under the examples/ folder.

Here is an example of basic usage:

'use strict';

import React, { Component } from 'react';

import {
  AppRegistry,
  StyleSheet,
  Text,
  NavigatorIOS,
  TouchableOpacity,
  Linking,
} from 'react-native';

import QRCodeScanner from 'react-native-qrcode-scanner';

class ScanScreen extends Component {
  onSuccess(e) {
    Linking.openURL(e.data).catch(err => console.error('An error occured', err));
  }

  render() {
    return (
      <NavigatorIOS
        initialRoute={{
          component: QRCodeScanner,
          title: 'Scan Code',
          passProps: {
            onRead: this.onSuccess.bind(this),
            topContent: (
              <Text style={styles.centerText}>
                Go to <Text style={styles.textBold}>wikipedia.org/wiki/QR_code</Text> on your computer and scan the QR code.
              </Text>
            ),
            bottomContent: (
              <TouchableOpacity style={styles.buttonTouchable}>
                <Text style={styles.buttonText}>OK. Got it!</Text>
              </TouchableOpacity>
            ),
          },
        }}
        style={{ flex: 1 }}
      />
    );
  }
}

const styles = StyleSheet.create({
  centerText: {
    flex: 1,
    fontSize: 18,
    padding: 32,
    color: '#777',
  },

  textBold: {
    fontWeight: '500',
    color: '#000',
  },

  buttonText: {
    fontSize: 21,
    color: 'rgb(0,122,255)',
  },

  buttonTouchable: {
    padding: 16,
  },
});

AppRegistry.registerComponent('default', () => ScanScreen);

Screenshot of the above:

Please open an issue if something doesn't work or is not clear enough.

Methods

reactivate()

Call this method to programmatically enabling scanning again. Use this by attaching a ref like so <QRCodeScanner ref={(node) = this.scanner = node}> and calling this.scanner.reactivate()

Props

onRead (required)

propType: func.isRequired default: (e) => (console.log('QR code scanned!', e))

Will call this specified method when a QR code or a barcode is detected in the camera's view passing in the event emitted upon reading the code.

fadeIn

propType: bool default: true

When set to true this ensures that the camera view fades in after the initial load up instead of being rendered immediately. Set this to false to prevent the animated fade in of the camera view.

reactivate

propType: bool default: false

When set to false, when a QR code is scanned, the QRCodeScanner will not scan another code until it is re-rendered. When set to true this will reactivate the scanning ability of the component.

reactivateTimeout

propType: number default: 0

Use this to configure how long it should take before the QRCodeScanner should reactivate.

topContent

propType: oneOfType([ PropTypes.element, PropTypes.string, ])

Use this to render any additional content at the top of the camera view.

bottomContent

propType: oneOfType([ PropTypes.element, PropTypes.string, ])

Use this to render any additional content at the bottom of the camera view.

containerStyle

propType: any

Use this to pass styling for the outermost container. Useful for adding margin/padding to account for navigation bar.

cameraStyle

propType: any

Use this to pass or overwrite styling for the camera window rendered.

topViewStyle

propType: any

Use this to pass or overwrite styling for the <View> that contains the topContent prop.

bottomViewStyle

propType: any

Use this to pass or overwrite styling for the <View> that contains the bottomContent prop.

showMarker

propType: boolean default: false

Use this to show marker on the camera scanning window

customMarker

propType: element

Pass a RN element/component to use it as a custom marker.

Contributors

• Matthew Constantine
• James Nolan
• Sava Vidakovic
• Maximo Dominguez
• Michael J Gallagher
• EzeRangel

License

See LICENSE.md

Thanks

Thanks to Lochlan Wansbrough for the react-native-camera module which provided me with an awesome example of how to set up this module.

This QR code scanner was inspired by the QR code scanner within Whatsapp.

Other notes

To do

• Document other complex examples
• Add some tests