How to delete tableview items after they are deleted in Firebase - ios

Question

My tableview currently updates my table and adds new items in real-time when they are added to my firebase database. The problem is that I cannot delete in real-time. I am storing my data from firebase in a local array, and then loading that array to the tableview.
I tried to condense my code a bit. I also tried to put the Firebase code that is inside my removeDeletedItems() function inside my populateArrays() function, and to put it after the .childAdded listener, but did not have luck with deleting the data in real-time.
override func viewDidLoad() {
super.viewDidLoad()
populateArrays()
}
func removeDeletedItems() {
let databaseRef = FIRDatabase.database().reference()
databaseRef.child("Users").observe(FIRDataEventType.childRemoved, with: { (FIRDataSnapshot) in
guard let emailToFind = FIRDataSnapshot.value as? String else { return }
for (index, email) in self.usernames.enumerated() {
if email == emailToFind {
let indexPath = IndexPath(row: index, section: 0)
self.usernames.remove(at: index)
self.tableView.deleteRows(at: [indexPath], with: .fade)
self.tableView.reloadData()
}
}
})
}
func populateArrays(){
let databaseRef = FIRDatabase.database().reference()
databaseRef.child("Users").observe(FIRDataEventType.childAdded, with: { (FIRDataSnapshot) in
if let data = FIRDataSnapshot.value as? NSDictionary {
if let name = data[Constants.NAME] as? String {
self.usernames.append(name)
self.removeDeletedItems()
self.tableView.reloadData()
}
}
})
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "cell", for: indexPath)
cell.textLabel?.text = usernames[indexPath.row]
return cell
}

Answer 1

Isn't the observed value always a dictionary? And shouldn't you check also for the name rather than the email?
The loop to find the name is not needed. There is a convenience function.
databaseRef.child("Users").observe(FIRDataEventType.childRemoved, with: { snapshot in
guard let data = snapshot.value as? [String:Any],
let nameToFind = data[Constants.NAME] as? String else { return }
if let index = self.usernames.index(of: nameToFind) {
let indexPath = IndexPath(row: index, section: 0)
self.usernames.remove(at: index)
self.tableView.deleteRows(at: [indexPath], with: .fade)
// don't reload the table view after calling `deleteRows`
}
}
})