Push SwifuUIscreen from AppDelegate - swift

Question

How can i push a SwiftUI screen from AppDelegate, e.x. when i click on a Remote notification in willPresent Method, i want the user to redirect to my TabBarView() with tab notification selected. I also need to have initialized my rootViewModel since i have logic there.
MainApp:
#main
struct MainApp: App {
#UIApplicationDelegateAdaptor(AppDelegate.self) var appDelegate
private var rootViewModel: MainViewModel
init() {
self.rootViewModel = MainViewModel()
}
var body: some Scene {
WindowGroup {
if authenticated {
Tabbar()
.environmentObject(rootViewModel)
} else {
SecondScreen()
.environmentObject(rootViewModel)
}
}
}
}
AppDelegate:
func userNotificationCenter(_ center: UNUserNotificationCenter, willPresent notification: UNNotification, withCompletionHandler completionHandler: #escaping (UNNotificationPresentationOptions) -> Void) {
print("willPresent notification")
let info = notification.request.content.userInfo
completionHandler([.badge, .sound, .banner])
}

Answer 1

If you want to control the tab selection programmatically from AppDelegate:
You have to use the TabBar initializer that takes a Binding to the selected tab, and
You have to be able to set the binding's value from AppDelegate.
Here's one solution.
First, define an enum representing the tab selection:
enum TabSelection: Hashable {
case firstTab
case secondTab
case thirdTab
}
Then, make your AppDelegate conform to ObservableObject and give it a Published property that holds the tab selection:
class AppDelegate: NSObject, UIApplicationDelegate, ObservableObject {
#Published var tabSelection: TabSelection = .firstTab
}
Finally, update your view to use tabSelection to control the selected tab:
Get a Binding<TabSelection> from appDelegate,
pass it to the TabView initializer, and
use the tag modifier on each tab subview.
struct MainApp: App {
#UIApplicationDelegateAdaptor(AppDelegate.self) var appDelegate
private var rootViewModel: MainViewModel
init() {
self.rootViewModel = MainViewModel()
}
var body: some Scene {
WindowGroup {
if rootViewModel.authenticated {
TabView(selection: _appDelegate.projectedValue.tabSelection) {
FirstTab()
.tag(TabSelection.firstTab)
SecondTab()
.tag(TabSelection.secondTab)
ThirdTab()
.tag(TabSelection.thirdTab)
}
.environmentObject(rootViewModel)
} else {
SecondScreen()
.environmentObject(rootViewModel)
}
}
}
}
You should be able to say $appDelegate.tabSelection to get the Binding. But I'm writing this answer on my iPad and the Swift Playgrounds app is complaining about $appDelegate, so I'm using _appDelegate.projectedValue.tabSelection to get the Binding.