How to Implement Native QR Code Scanner Integration in Your iOS WebView App using Swift and WebViewGold

Integrating a native QR code scanner directly into your WebView-based iOS app enhances the user experience significantly by allowing seamless interaction between web content and device hardware. If your iOS application is built using WebViewGold, the solution becomes even easier. WebViewGold offers an intuitive and efficient way to transform your existing website into fully functional native apps for iOS, providing native QR scanner integration with minimal hassle.

Why Use Native QR Code Scanning in Your WebView App

QR codes have become an integral part of everyday digital interactions, offering quick access to websites, payment systems, contact information, and more. By integrating native QR scanning functionality in your WebView-based app, you can:

• Provide users a smooth, seamless scanning experience without requiring third-party apps.
• Reduce user frustration and improve overall usability.
• Maintain user retention by offering convenient native features within your app.

Understanding QR Code Integration with WebViewGold

When building WebView apps, developers often encounter challenges when trying to include native device functionalities such as camera access or QR code scanning. Thankfully, using WebViewGold simplifies this greatly. WebViewGold quickly converts your website into feature-rich native applications on iOS, and conveniently provides built-in hooks for native QR scanning functionalities.

You don’t need in-depth Swift expertise to get started—WebViewGold‘s intuitive implementation ensures you spend less time coding and more time enhancing your app’s features.

Step-by-Step Guide: Adding Native QR Scanner Integration Using Swift and WebViewGold

Step 1: Prepare Your WebViewGold Xcode Project
First, ensure you have your WebViewGold-generated Xcode project open. This process assumes you’ve already followed WebViewGold‘s quick setup instructions to turn your website into a functioning, native app.

Step 2: Request Camera Access Permission
You’ll need to request camera access permission in your app’s Info.plist. To do this, add the key-value pair below:

<key>NSCameraUsageDescription</key>
<string>This app uses your camera to scan QR codes.</string>

This informs the user clearly why your app requires camera access.

Step 3: Implement QR Scanner Feature using AVFoundation
To integrate a native scanner, you’ll leverage Apple’s AVFoundation framework. Add this import statement at the top of your ViewController.swift file:

import AVFoundation

Define your AVCaptureSession to manage camera input:

var captureSession: AVCaptureSession!
var previewLayer: AVCaptureVideoPreviewLayer!

Next, implement the scanning logic within your existing view controller:

func startQRCodeScanning() {
    captureSession = AVCaptureSession()

    guard let videoCaptureDevice = AVCaptureDevice.default(for: .video) else { return }
    let videoInput: AVCaptureDeviceInput

    do {
        videoInput = try AVCaptureDeviceInput(device: videoCaptureDevice)
    } catch {
        return
    }

    if (captureSession.canAddInput(videoInput)) {
        captureSession.addInput(videoInput)
    } else {
        return
    }

    let metadataOutput = AVCaptureMetadataOutput()
    if (captureSession.canAddOutput(metadataOutput)) {
        captureSession.addOutput(metadataOutput)

        metadataOutput.setMetadataObjectsDelegate(self, queue: DispatchQueue.main)
        metadataOutput.metadataObjectTypes = [.qr]
    } else {
        return
    }

    previewLayer = AVCaptureVideoPreviewLayer(session: captureSession)
    previewLayer.frame = view.layer.bounds
    previewLayer.videoGravity = .resizeAspectFill
    view.layer.addSublayer(previewLayer)

    captureSession.startRunning()
}

Conform your ViewController class to the AVCaptureMetadataOutputObjectsDelegate protocol by implementing this delegate method:

extension ViewController: AVCaptureMetadataOutputObjectsDelegate {
    func metadataOutput(_ output: AVCaptureMetadataOutput, didOutput metadataObjects: [AVMetadataObject], from connection: AVCaptureConnection) {
        captureSession.stopRunning()

        if let metadataObject = metadataObjects.first {
            guard let readableObject = metadataObject as? AVMetadataMachineReadableCodeObject else { return }
            guard let scannedValue = readableObject.stringValue else { return }

            // Handle scanned QR code result here
            handleScannedQRCode(scannedValue)
        }
    }

    func handleScannedQRCode(_ value: String) {
        // Pass scanned data back to the WebView or perform relevant action
        print(Scanned QR code: \(value))

        // Example: Inject scanned result back into the WebView
        let jsCode = window.handleQRCodeResult('\(value)');
        webView.evaluateJavaScript(jsCode, completionHandler: nil)
    }
}

Step 4: Trigger Scanner via JavaScript Interface
With WebViewGold, it’s straightforward to trigger native actions from your website’s JavaScript. Define a custom JavaScript handler in your WebViewGold configuration to intercept calls from your website:

// JavaScript example to trigger QR scanner from your website
window.webkit.messageHandlers.qrScanner.postMessage(startScan);

Then, in Swift, set up the WKScriptMessageHandler:

extension ViewController: WKScriptMessageHandler {
    func userContentController(_ userContentController: WKUserContentController, didReceive message: WKScriptMessage) {
        if message.name == qrScanner, let action = message.body as? String, action == startScan {
            startQRCodeScanning()
        }
    }
}

Final Thoughts: Simplifying Your App Development Process with WebViewGold

By utilizing WebViewGold tools and Swift’s powerful iOS SDK, integrating native hardware functionalities like QR code scanning into your web-to-app strategy becomes straightforward. WebViewGold streamlines your entire development lifecycle by simplifying tasks that would otherwise require extensive development effort. Leveraging its comprehensive features helps you deliver highly interactive, user-friendly apps efficiently and cost-effectively.