Reputation: 45
After adding 10 child I want to delete the first child whenever a new child added in the database.
Upvotes: 0
Views: 46
Reputation: 39
The best way to do this is to use the firebase cloud functions. Cloud functions is like are triggers ready to perform a certain task, such as when an item is created, added, deleted or updated, and much more.
Read about it on: https://firebase.google.com/docs/functions/get-started
Upvotes: 0
Reputation: 3699
this may help you
rootref.child("messeges").child(YourInnerChildKey).addValueEventListener(new ValueEventListener() {
@Override
public void onDataChange(@NonNull DataSnapshot dataSnapshot) {
int count = 0;
String firstNodeId;
for (DataSnapshot ds : dataSnapshot.getChildren()) {
if (count == 0) firstNodeId = ds.getKey();
count++;
}
if(count > 10){
rootref.child("messeges").child(YourInnerChildKey).removeEventListener(this);
firebase.child(firstNodeId).removeValue();
rootref.child("messeges").child(YourInnerChildKey).addValueEventListener(this);
}
}
Upvotes: 1