alertaffirm.swift

//alert with the option to dismiss
.alert(isPresented:$showingAlert) {
  Alert(title: Text("Are you sure you want to leave?"), 
        message: Text("We'll miss you!"), 
        primaryButton: .default(Text("Leave")) {
          self.presentationMode.wrappedValue.dismiss()
        }, 
        secondaryButton: .cancel())
}