Cristian.R Cristian.R - 5 months ago 69
Android Question

Android: Firebase ChildEventListener() not working

I am working in my app with Firebase and I tried to use onChildAdded() callback but I think I am doing something wrong because I get no response.

/**
* Constructor
*/
private FirebaseManager(Context context) {
Firebase.setAndroidContext(context);
Firebase.getDefaultConfig().setPersistenceEnabled(true);
mFirebaseRef = new Firebase(FIREBASE_URL);
}





public void checkUsers() {
Firebase checkRef = mFirebaseRef.child("/data/users/");
// Also tried
// Firebase checkRef = mFirebaseRef.child("data").child("users");
checkRef.addChildEventListener(new ChildEventListener() {
@Override
public void onChildAdded(DataSnapshot dataSnapshot, String s) {
Log.d(TAG,"New child added");
}

@Override
public void onChildChanged(DataSnapshot dataSnapshot, String s) {

}

@Override
public void onChildRemoved(DataSnapshot dataSnapshot) {

}

@Override
public void onChildMoved(DataSnapshot dataSnapshot, String s) {

}

@Override
public void onCancelled(FirebaseError firebaseError) {

}


});
}


In onCreate() of my MainActivity I authenticate the user and the call checkUsers(). After that I manually add a new user in database. But I get nothing in log.
This is the json structure:

enter image description here

What am I doing wrong?

Answer

I got it. There was a concurrency problem. I called checkUsers() in onCreate() of the MainActivity but it needs to be called in onAuthenticated(), because the user was authenticated after the method checkUsers() tried to set listeners.

I got a LOG about the failure of accessing database:

W/SyncTree: Listen at / failed: FirebaseError: Permission denied

but didn't seen it because I was following a specific TAG with logcat Search.