Swift Firebase Delete An user when app will terminate - ios

Question

Im trying to Delete user when app will terminate but this does not work.
If I have an anonymous user signed in and the user close the app I don't want firebase to save the anonymous user. I want to delete it. This is my current code. Thank you in advance
func applicationWillTerminate(_ application: UIApplication) {
// Called when the application is about to terminate. Save data if appropriate. See also applicationDidEnterBackground:.
if let users = Auth.auth().currentUser {
if !users.isAnonymous {
return
}else {
users.delete(completion: { (error) in
if error != nil {
print(error!)
return
}
try! Auth.auth().signOut()
print("Anonymous user deleted")
})
}
}
}

Answer 1

I added listerners in the ViewDidLoad to the screen where I want the user the be deleted from. Like this:
NotificationCenter.default.addObserver(self, selector: #selector(suspending), name: NSNotification.Name.UIApplicationWillResignActive, object: nil)
NotificationCenter.default.addObserver(self, selector: #selector(suspending), name: NSNotification.Name.UIApplicationWillTerminate, object: nil)
And then I have this function to delete the user:
#objc func suspending () {
if Auth.auth().currentUser != nil {
let user = Auth.auth().currentUser
user?.delete { error in
if let error = error {
print("An error happened delting the user.")
} else {
print("Account succesfully deleted.")
}
}
}
}
The only thing that could happen is, that you need to re-authenticate. If that's the case, than follow this answer to implement it as well

Answer 2

Hei #pprevalon, I've been trying to achieve the same thing as you, just by updating a value on appWillTerminate, but here's what I found out from other members
Your implementation of this method has approximately five seconds to perform any tasks and return. If the method does not return before time expires, the system may kill the process altogether.
Still trying to figure out a way, since it happens 1/10 times for the func appWillTerminate to be called, but I cannot count on that.
P.S. Besides that, think about this : If the user switches from active -> background at first, followed by background -> kill app, the method will never get called.