Load Qr codes to multiple view controller (Xcode) - ios

Question

I'm currently working on a project(using Xcode-Swift) where I'm required to developed a QR code scanner quiz app for an event. The user must scan 10 qr codes from 10 booths respectively(1 booth with 1 qr code & 1 booth consist of 1 qn). Hence, i have 10 different qr code images, may i know how do i open specific controller based on the qr code scanned? As of right now, my QR code scanner is only able to scan the qr code to a web URL instead. I've already done the layout and buttons for my quiz qns, I only need the QR code to link to my QuestionControllers instead. Thank you in advance.
This is my QRScannerController.swift
import UIKit
import AVFoundation
class QRScannerController: UIViewController, AVCaptureMetadataOutputObjectsDelegate {
#IBOutlet var messageLabel:UILabel!
#IBOutlet var topbar: UIView!
var captureSession:AVCaptureSession?
var videoPreviewLayer:AVCaptureVideoPreviewLayer?
var qrCodeFrameView:UIView?
let supportedCodeTypes = [AVMetadataObjectTypeUPCECode,
AVMetadataObjectTypeCode39Code,
AVMetadataObjectTypeCode39Mod43Code,
AVMetadataObjectTypeCode93Code,
AVMetadataObjectTypeCode128Code,
AVMetadataObjectTypeEAN8Code,
AVMetadataObjectTypeEAN13Code,
AVMetadataObjectTypeAztecCode,
AVMetadataObjectTypePDF417Code,
AVMetadataObjectTypeQRCode]
override func viewDidLoad() {
super.viewDidLoad()
// Get an instance of the AVCaptureDevice class to initialize a device object and provide the video as the media type parameter.
let captureDevice = AVCaptureDevice.defaultDevice(withMediaType: AVMediaTypeVideo)
do {
// Get an instance of the AVCaptureDeviceInput class using the previous device object.
let input = try AVCaptureDeviceInput(device: captureDevice)
// Initialize the captureSession object.
captureSession = AVCaptureSession()
// Set the input device on the capture session.
captureSession?.addInput(input)
// Initialize a AVCaptureMetadataOutput object and set it as the output device to the capture session.
let captureMetadataOutput = AVCaptureMetadataOutput()
captureSession?.addOutput(captureMetadataOutput)
// Set delegate and use the default dispatch queue to execute the call back
captureMetadataOutput.setMetadataObjectsDelegate(self, queue: DispatchQueue.main)
captureMetadataOutput.metadataObjectTypes = supportedCodeTypes
// Initialize the video preview layer and add it as a sublayer to the viewPreview view's layer.
videoPreviewLayer = AVCaptureVideoPreviewLayer(session: captureSession)
videoPreviewLayer?.videoGravity = AVLayerVideoGravityResizeAspectFill
videoPreviewLayer?.frame = view.layer.bounds
view.layer.addSublayer(videoPreviewLayer!)
// Start video capture.
captureSession?.startRunning()
// Move the message label and top bar to the front
view.bringSubview(toFront: messageLabel)
view.bringSubview(toFront: topbar)
// Initialize QR Code Frame to highlight the QR code
qrCodeFrameView = UIView()
if let qrCodeFrameView = qrCodeFrameView {
qrCodeFrameView.layer.borderColor = UIColor.green.cgColor
qrCodeFrameView.layer.borderWidth = 2
view.addSubview(qrCodeFrameView)
view.bringSubview(toFront: qrCodeFrameView)
}
} catch {
// If any error occurs, simply print it out and don't continue any more.
print(error)
return
}
}
// MARK: - AVCaptureMetadataOutputObjectsDelegate Methods
func captureOutput(_ captureOutput: AVCaptureOutput!, didOutputMetadataObjects metadataObjects: [Any]!, from connection: AVCaptureConnection!) {
// Check if the metadataObjects array is not nil and it contains at least one object.
if metadataObjects == nil || metadataObjects.count == 0 {
qrCodeFrameView?.frame = CGRect.zero
messageLabel.text = "No QR/barcode is detected"
return
}
// Get the metadata object.
let metadataObj = metadataObjects[0] as! AVMetadataMachineReadableCodeObject
if supportedCodeTypes.contains(metadataObj.type) {
// If the found metadata is equal to the QR code metadata then update the status label's text and set the bounds
let barCodeObject = videoPreviewLayer?.transformedMetadataObject(for: metadataObj)
qrCodeFrameView?.frame = barCodeObject!.bounds
if metadataObj.stringValue != nil {
let url = URL(string: metadataObj.stringValue)!
if #available(iOS 10.0, *) {
UIApplication.shared.open(url, options: [:], completionHandler: nil)
} else {
UIApplication.shared.openURL(url)
}
}
}
}
}
And this is my question1controller
import UIKit
class Quiz1Controller: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
}
}
Image of QrCodeScanner and Question views

Answer 1

Q: may i know how do i open specific controller based on the qr code scanned?
I'd recommend you to create a QR scanner class and a delegate. Then create a "flow controller" which will control your application flow like reading QR x will present the controller x and so on. Some idea:
WARNING: Untested code
protocol QRHandler {
func didRead(qr: String)
}
class QRCodeScanner {
weak var delegate: QRHandler?
func startScan() {
// your scan code
// if qr read
delegate?.didRead(qr: qrRead)
}
}
class FlowController: UINavagationController /*or UITabBarController or something else you want*/ {
private var currentVC: String
private let scanner = QRCodeScanner()
func init() {
scanner.delegate = self
scanner.startScan()
}
// MARK: - QRHandler
func didRead(qr: String) {
switch currentVC {
case "X":
// present Y
case "Y":
// present Z
default:
// unexpected vc...
}
}
}