/expo-qrcode-scanner

A node module for that limits scan area to the center for easy scanning multiple QR codes, camera distance is also customizable with respect to QR code

Primary LanguageJavaScript

QR Code Scanner Module for Expo 📸

This module provides a React Native component for scanning QR codes, specifically designed for use with Expo. It offers a customizable QR code scanning experience, allowing users to specify various parameters and styles.

Installation 📦

To use this module in your Expo project, install it via npm or yarn:

npm install expo-qrcode-scanner
# or
yarn add expo-qrcode-scanner

Usage 🚀

First, import the QRCodeScanner into your React Native component:

import QRCodeScanner from 'expo-qrcode-scanner';

Then, you can use the QRCodeScanner in your component's render method:

import React from 'react';
import { View } from 'react-native';
import QRCodeScanner from 'expo-qrcode-scanner';

const YourComponent = () => {
    const handleScanSuccess = (scanData) => {
        // Handle successful scan
        console.log('QR Code Scanned:', scanData);
    };

    const handleScanFail = () => {
        // Handle scan failure
        console.log('Failed to scan QR Code.');
    };

    return (
        <View style={{ flex: 1 }}>
            <QRCodeScanner
                onScanSuccess={handleScanSuccess}
                onScanFail={handleScanFail}
                // Additional props
            />
        </View>
    );
};

export default YourComponent;

Requesting Camera Permissions 🎥

Before scanning QR codes, your app must ask the user for permission to access the camera. You can do this using Expo's Permissions API:

import { useState, useEffect } from 'react';
import { Text, View } from 'react-native';
import QRCodeScanner from 'expo-qrcode-scanner';
import {BarCodeScanner} from 'expo-barcode-scanner';

const CameraScreen = () => {
    const [hasPermission, setHasPermission] = useState(null);

    useEffect(() => {
        (async () => {
            const { status } = await BarCodeScanner.requestPermissionsAsync();
            setHasPermission(status === 'granted');
        })();
    }, []);

    if (hasPermission === null) {
        return <View />;
    }
    if (hasPermission === false) {
        return <Text>No access to camera</Text>;
    }

    return (
        <View style={{ flex: 1 }}>
            <QRCodeScanner
                onScanSuccess={(scanData) => console.log(scanData)}
                onScanFail={() => console.log('Failed to scan')}
                // Additional props
            />
        </View>
    );
};

Props 📐

The QRCodeScannerComponent accepts the following props:

Prop Type Default Required Description
style Object - No A custom style object to apply to the scanner component.
onScanSuccess Function - No A callback function invoked when a QR code is successfully scanned.
onScanFail Function - No A callback function invoked when a scan attempt fails.
toleranceFactor Number 0.5 No A number representing the tolerance factor for QR code centering.
minSize Number 140 Yes The minimum size for a QR code to be considered valid.
maxSize Number 220 Yes The maximum size for a QR code to be considered valid.
scanningInfinitely boolean false Yes Scan QR code continously

Contributing 🤝

Contributions to this module are welcome. Please ensure that your code adheres to the existing style and functionality.

License 📄

This module is licensed under the MIT License.