ViewController.swift for medium post about Audio Unit V3 Extensions updated adding plugin view controller

ViewController.swift

import Cocoa
import AUFramework

class ViewController: NSViewController {
    
    private var audioPlayer: AudioPlayer!
    private var pluginVC: AudioUnitViewController!
    
    @IBOutlet weak var auContainer: NSView!
    
    override func viewDidLoad() {
        super.viewDidLoad()
        guard let url = Bundle.main.url(forResource: "z", withExtension: "wav") else {
            fatalError("can't create url from resource")
        }
        audioPlayer = AudioPlayer(url)
        addPluginView()
        audioPlayer.play()
    }
    
    private func addPluginView() {
        let builtInPluginsURL = Bundle.main.builtInPlugInsURL
        guard let pluginURL = builtInPluginsURL?.appendingPathComponent("VolumePlugin.appex") else {
            fatalError("cannot get plugin URL")
        }
        let appExtensionBundle = Bundle(url: pluginURL)
        
        pluginVC = AudioUnitViewController(nibName: "AudioUnitViewController", bundle: appExtensionBundle)
        let auView = pluginVC.view
        auView.frame = auContainer.bounds
        auContainer.addSubview(auView)
    }
}