CyberBison

func prepare(completionHandler: @escaping (Error?) -> Void){
    func createCaptureSession(){
        self.captureSession = AVCaptureSession()
    }
    func configureCaptureDevices() throws {
        let camera = AVCaptureDevice.default(.builtInWideAngleCamera, for: AVMediaType.video, position: .front)
        
        self.frontCamera = camera
        
        try camera?.lockForConfiguration()

CyberBison

func displayPreview(on view: UIView) throws {
    guard let captureSession = self.captureSession, captureSession.isRunning else { throw CameraControllerError.captureSessionIsMissing }
        
    self.previewLayer = AVCaptureVideoPreviewLayer(session: captureSession)
        self.previewLayer?.videoGravity = AVLayerVideoGravity.resizeAspectFill
    self.previewLayer?.connection?.videoOrientation = .portrait
    
    view.layer.insertSublayer(self.previewLayer!, at: 0)
    self.previewLayer?.frame = view.frame
}

CyberBison

override func viewDidLoad() {
                
    previewView = UIView(frame: CGRect(x:0, y:0, width: UIScreen.main.bounds.size.width, height: UIScreen.main.bounds.size.height))
    previewView.contentMode = UIView.ContentMode.scaleAspectFit
    view.addSubview(previewView)
    
    cameraController.prepare {(error) in
        if let error = error {
            print(error)
        }

CyberBison

extension CameraViewController : UIViewControllerRepresentable{
    public typealias UIViewControllerType = CameraViewController
    
    public func makeUIViewController(context: UIViewControllerRepresentableContext<CameraViewController>) -> CameraViewController {
        return CameraViewController()
    }
    
    public func updateUIViewController(_ uiViewController: CameraViewController, context: UIViewControllerRepresentableContext<CameraViewController>) {
    }
}