I want to make a boolean method which can check if a user's nickname is unique, but I'm faced with a problem.
T have such structure of database:
I have this function:
public boolean isNickUnique(String nickname, DatabaseReference ref){
final boolean[] res = {true};
ref = ref.child(nickname);
ref.addListenerForSingleValueEvent(new ValueEventListener() {
@Override
public void onDataChange(@NonNull DataSnapshot snapshot) {
if(snapshot.exists())
res[0] = false;
}
@Override
public void onCancelled(@NonNull DatabaseError error) {
}
});
return res[0];}
The OnDataChange method checks the nickname uniqueness successfully, but the isNickUnique method returns the result before the ValueEventListener finishes his work. How can I solve this problem?
