refactor: AuthPickerView sheet and Navigation stack

[demolaf]

Proof of Concept

• Allow the user to pass in their app via closure on AuthPickerView:

AuthPickerView {
  usersApp  // Your app's authenticated/unauthenticated content
}
.environment(authService)

var usersApp: some View {
    NavigationStack {
      VStack {
        if authService.authenticationState == .unauthenticated {
          Text("Not Authenticated")
        } else {
          Text("Authenticated - \(authService.currentUser?.email ?? "")")
          Button {
            authService.isPresented = true  // Reopen the sheet so user can manage account
          } label: {
            Text("Manage Account")
          }
          .buttonStyle(.bordered)
          Button {
            Task {
              try? await authService.signOut()
            }
          } label: {
            Text("Sign Out")
          }
          .buttonStyle(.borderedProminent)
        }
      }
      .navigationTitle("Firebase UI Demo")
    }

• The AuthPickerView is now wrapped in a .sheet(). This means:
  • The authentication picker appears as a modal sheet over your app.
  • It prevents navigation conflicts between the SDK's navigation and your app's navigation.
  • The developer's app content (usersApp) is always visible underneath.
  • Can use NavigationStack internally as the sheet provides its own context outside of user's app.
• Implemented our own Navigator class to manage different Auth Views internally (i.e. doesn't affect user's app). This allows us to pop to root from any View and clear the stack. For example, when user signs out, we need to clear the stack so they can't swipe back to authenticated View.

Developer Notes

• NavigationStack for routing
• Updated UI for EmailAuthView, PasswordRecoveryView, PhoneAuthView (now split between EnterPhoneNumberView and EnterVerificationCodeView), EmailLinkView.
• Updated styling for buttons
• Introduced FirebaseAuthUIComponents package which contains resources, UI components and provider styles.
• shouldHideCancelButton in AuthUIConfiguration shows "x" close button in AuthPickerView toolbar
• interactiveDismissEnabled for AuthPickerView sheet
• Removed isLimitedLogin flag from FacebookAuthProviderSwift, App Tracking Transparency (ATT) drives limited login internally

Simulator.Screen.Recording.-.iPhone.17.Pro.Max.-.2025-10-30.at.17.03.42.mov

[russellwheatley]

Looks really good so far! Hopefully the changes I've requested aren't too drastic

[russellwheatley]

Suggested change

	Text("Authenticated - \(authService.currentUser?.email ?? "")")
	Text("Authenticated - \(authService.currentUser?.email ?? "")")
	Button {
	authService.isPresented = true // Reopen the sheet
	} label: {
	Text("Manage Account")
	}
	.buttonStyle(.bordered)

[russellwheatley]

for purpose of demonstration, let's show how to access the SignedInView so the user can manager their account