How to add Google AdMob ad banner to SwiftUI with Apple Tracking Transparency (ATT) framework

Google AdMob

Ad units > Add ad unit > Banner

App ID: ca-app-pub-1111222233334444~1234567890 Ad unit ID: ca-app-pub-1111222233334444/9876543210

XCode

XCode > File > Add Package Dependencies

Add Package: Google Mobile Ads SDK

You should be able to see the added packages in:
1. Navigator under "Package Dependencies" e.g.
```
> 📦 GoogleMobileAds 11.8.0
> 📦 GoogleUserMessagingPlatform 2.5.0
```
If you can't see "Package Dependenceis" in the Navigator, try restarting the XCode
1. Project -> Targets -> General tap -> "Frameworks, Libraries, and Embedded Content"
```
🏛️ GoogleMobileAds
```
Add below to the Info.plist

    Add Key: "GADApplicationIdentifier"
    Value: "ca-app-pub-1111222233334444~1234567890"

How to add to the Info.plist:

Select project in the Navigation -> Targets > Info > Custom macOS Application Target Properties: Hover over pre-existing Keys and click (+) -> fill in the Key and Value pair. This will create Info on the Navigator if not already exists. This can be seen as Info.plist in the Finder.
If Info exists on the Navigator: right click -> Open As -> Source Code; add to the XML file.

<dict>
	<key>GADApplicationIdentifier</key>
	<string>ca-app-pub-1639129328565259~1986806680</string>
...
</dict>

Swift files

File contents to be updated as my code evolves

MainApp.swift

Get the testDeviceIdentifiers from the warnings: XCode -> Debug Area -> Console.

// MainApp.swift
 
import SwiftUI
import GoogleMobileAds
 
@main
struct MainApp: App {
    @UIApplicationDelegateAdaptor(AppDelegate.self) var appDelegate
    private let testDeviceIdentifiers = [ "..." ]
 
    init() {
        GADMobileAds.sharedInstance().start(completionHandler: nil)
        GADMobileAds.sharedInstance().requestConfiguration.testDeviceIdentifiers = self.testDeviceIdentifiers
    }
 
    var body: some Scene {
        WindowGroup {
            ContentView()
        }
    }
}

AppDelegate.swift

// AppDelegate.swift
 
import SwiftUI
 
class AppDelegate: NSObject, UIApplicationDelegate {
    static var orientationLock = UIInterfaceOrientationMask.portrait
 
    func application(_ application: UIApplication, supportedInterfaceOrientationsFor window: UIWindow?) -> UIInterfaceOrientationMask {
        return AppDelegate.orientationLock
    }
}

AdBannerView.swift

// AdBannerView.swift
 
import SwiftUI
import GoogleMobileAds
import AppTrackingTransparency
 
let AD_UNIT_ID = "ca-app-pub-1111222233334444/9876543210"
 
struct AdBannerViewWrapper: View {
    @Environment(\.scenePhase) private var scenePhase
    @State private var shouldReload = false
    @State private var adHeight: CGFloat = 50
 
    var body: some View {
        VStack(spacing: 0) {
            Rectangle()
                .fill(.gray.opacity(0.1))
                .frame(height: 8)
 
            AdBannerView(shouldReload: $shouldReload)
                .frame(height: adHeight)
                .background(.gray.opacity(0.1))
        }
        .onAppear {
            adHeight = GADPortraitAnchoredAdaptiveBannerAdSizeWithWidth(UIScreen.main.bounds.width).size.height
        }
        .onChange(of: scenePhase) { newPhase in
            if newPhase == .active {
                DispatchQueue.main.async {
                    shouldReload = true
                }
            }
        }
    }
}
 
struct AdBannerView: UIViewRepresentable {
    @Binding var shouldReload: Bool
    @State private var isTrackingAuthorized = false
 
    func makeUIView(context: Context) -> GADBannerView {
        let adSize = GADPortraitAnchoredAdaptiveBannerAdSizeWithWidth(UIScreen.main.bounds.width)
        let bannerView = GADBannerView(adSize: adSize)
        bannerView.adUnitID = AD_UNIT_ID
        bannerView.rootViewController = getRootViewController()
 
        // below line can be removed if Apple Tracking Transparency (ATT) popup appears without delay
        DispatchQueue.main.asyncAfter(deadline: .now() + 2.0) {
            Task {
                let authorized = await requestTrackingAuthorization()
                DispatchQueue.main.async {
                    self.isTrackingAuthorized = authorized
                    loadAd(bannerView: bannerView)
                }
            }
        }
 
        return bannerView
    }
 
    func updateUIView(_ uiView: GADBannerView, context: Context) {
        if shouldReload {
            loadAd(bannerView: uiView)
            DispatchQueue.main.async {
                shouldReload = false
            }
        }
    }
 
    private func loadAd(bannerView: GADBannerView) {
        let request = GADRequest()
        if !isTrackingAuthorized {
            let extras = GADExtras()
            extras.additionalParameters = ["npa": "1"]
            request.register(extras)
        }
        bannerView.load(request)
    }
 
    private func getRootViewController() -> UIViewController? {
        guard let windowScene = UIApplication.shared.connectedScenes
            .first(where: { $0.activationState == .foregroundActive}) as? UIWindowScene else {
            return nil
        }
        return windowScene.windows.first?.rootViewController
    }
 
    @available(iOS 14, *)
    private func requestTrackingAuthorization() async -> Bool {
        let status = await ATTrackingManager.requestTrackingAuthorization()
 
        switch status {
        case .authorized:
            print("Tracking authorized 🟢")
            return true
        case .denied:
            print("Tracking denied ❌")
            return false
        case .restricted:
            print("Tracking restricted ❌")
            return false
        case .notDetermined:
            print("Tracking not determined ❌")
            return false
        @unknown default:
            print("Unknown tracking status ❓")
            return false
        }
    }
}

Use in view

AdBannerViewWrapper()