iOS SWIFT: Unable to delete user from Firebase Database - ios

Question

I want to delete my current user from Firebase. The authenticated user gets deleted however, I am unable to delete the data for that user in the database. What am i doing wrong?
This is my delete user method....
FIRAuth.auth()?.signIn(withEmail: (emailTextField?.text)! , password: (passwordTextField?.text)!, completion: { (user, error) in
if error == nil {
print("User Authenticate!!!")
let user = FIRAuth.auth()?.currentUser
user?.delete(completion: { (error) in
if error != nil {
print("Error unable to delete user")
} else {
DataService.ds.deleteCurrentFirebaseDBUser()
KeychainWrapper.standard.removeObject(forKey: KEY_UID)
self.performSegue(withIdentifier: "goToLogin", sender: nil)
}
})
} else {
//Password was wrong, unable to authenicate user. Data is not updated
print("!!!ALERT!!! Unable to authenticate user")
let alert = UIAlertController(title: "Incorrect Password", message: "Please re-enter your password", preferredStyle: UIAlertControllerStyle.alert)
alert.addAction(UIAlertAction(title: "OK", style: UIAlertActionStyle.default, handler: nil))
self.present(alert, animated: true, completion: nil)
}
})
Firebase Rules:
{
"rules": {
"users": {
"$uid": {
".read": "$uid === auth.uid",
".write": "$uid === auth.uid"
}
}
}
}
Database:
App
-> users
->
4erkjkl543jfe46
->name
->email
ERRORS:
2017-01-21 21:33:10.321704 APP[11582:4102711] [FirebaseDatabase] setValue: or removeValue: at /users/4erkjkl543jfe46 failed: permission_denied
Optional(Error Domain=com.firebase Code=1 "Permission denied" UserInfo={NSLocalizedDescription=Permission denied})

Answer 1

I'm having the same issue. You are not able to make use of your function deleteCurrentFirebaseDBUser() because the Firebase delete function (if successful) removes the user auth object.
As a result user is not authenticated anymore at the time you want to delete user's data in database with deleteCurrentFirebaseDBUser().
Currently I delete user's data in database before Firebase delete function which is not the ideal solution.

Answer 2

We can delete user from both side authentication and database.But before that we need to reauthenticate user first then we get latest token to delete the user.
Here is the pretty code:
let user = Auth.auth().currentUser
user?.reauthenticate(with:credential) { error in
if let error = error {
// An error happened.
showAlertWithErrorMessage(message: error.localizedDescription)
} else {
// User re-authenticated.
user?.delete { error in
if let error = error {
// An error happened.
showAlertWithErrorMessage(message: error.localizedDescription)
} else {
// Account deleted.
let userID = HelperFunction.helper.FetchFromUserDefault(name: kUID)
Database.database().reference(fromURL: kFirebaseLink).child(kUser).child(userID).removeValue()
try! Auth.auth().signOut()
showAlertWithErrorMessage(message: "Your account deleted successfully...")
return
}
}
}
}
100% working in my project and well tested

Answer 3

for just to delete a child from Firebase use "removeValue()"
var db: DatabaseReference!
override func viewDidLoad() {
super.viewDidLoad()
db = Database.database().reference()
deleteByID()
}
func deleteByID(){
db.child("YOURID").removeValue()
}

Answer 4

Swift 5 | Firebase 8.11.0
As #SvshX said, deleting the user data before deleting the actual user is the only available solution.
The problem with this method is that deleting the user might give an error like AuthErrorCode.requiresRecentLogin, then the data will be deleted but the user will not.
This error is given when the last authentication of the user was more than 5 minuets ago (from Firebase Docs)
So, fixing both of the issues can be achieved by using DispatchGroup and checking the lastSignInDate.
This is my final solution (just call deleteUserProcess()):
let deleteDataGroup = DispatchGroup()
func deleteUserProcess() {
guard let currentUser = Auth.auth().currentUser else { return }
deleteUserData(user: currentUser)
// Call deleteUser only when all data has been deleted
deleteDataGroup.notify(queue: .main) {
self.deleteUser(user: currentUser)
}
}
/// Remove data from Database & Storage
func deleteUserData(user currentUser: User) {
// Check if `currentUser.delete()` won't require re-authentication
if let lastSignInDate = currentUser.metadata.lastSignInDate,
lastSignInDate.minutes(from: Date()) >= -5 {
deleteDataGroup.enter()
Database.database().reference().child(userId).removeValue { error, _ in
if let error = error { print(error) }
self.deleteDataGroup.leave()
}
// Delete folders from Storage isn't possible,
// so list and run over all files to delete each one independently
deleteDataGroup.enter()
Storage.storage().reference().child(userId).listAll { list, error in
if let error = error { print(error) }
list.items.forEach({ file in
self.deleteDataGroup.enter()
file.delete { error in
if let error = error { print(error) }
self.deleteDataGroup.leave()
}
})
deleteDataGroup.leave()
}
}
}
/// Delete user
func deleteUser(user currentUser: User) {
currentUser.delete { error in
if let error = error {
if AuthErrorCode(rawValue: error._code) == .requiresRecentLogin {
reauthenticate()
} else {
// Another error occurred
}
return
}
// Logout properly
try? Auth.auth().signOut()
GIDSignIn.sharedInstance.signOut()
LoginManager().logOut()
// The user has been deleted successfully
// TODO: Redirect to the login UI
}
}
func reauthenticate() {
// TODO: Display some UI to get credential from the user
let credential = ... // Complete from https://stackoverflow.com/a/38253448/8157190
Auth.auth().currentUser?.reauthenticate(with: credential) { _, error in
if let error = error {
print(error)
return
}
// Reload user (to update metadata.lastSignInDate)
Auth.auth().currentUser?.reload { error in
if let error = error {
print(error)
return
}
// TODO: Dismiss UI
// Call `deleteUserProcess()` again, this time it will delete the user
deleteUserProcess()
}
}
}
The minuets function can be added in an extension to Date (thanks to Leo Dabus):
extension Date {
/// Returns the amount of minutes from another date
func minutes(from date: Date) -> Int {
return Calendar.current.dateComponents([.minute], from: date, to: self).minute ?? 0
}
}