Startlistening In Firebase Ui

My app crashes when I sign in. The issue stems from the load function. when it initiates the adapter.startListening(); I am not sure if it is from versions conflict or otherwise. p

Solution 1:

I managed to solve it

instead of :

@OverrideprotectedvoidonStart() {
    super.onStart();
    adapter.startListening();
}

in MainActivity. Transfer this line adapter.startListening(); inside the loadMenu() before setting the adapter:

adapter.startListening();
recycler_menu.setAdapter(adapter);

Solution 2:

The error you get is:

Attempt to invoke virtual method 'void com.firebase.ui.database.FirebaseRecyclerAdapter.startListening()' on a null object reference at abcd.com.eatme.MainActivity.onStart(MainActivity.java:55)

If you go to line 55 of MainActivity.java that the error mentions, it is in onStart():

@OverrideprotectedvoidonStart() {
    super.onStart();
    adapter.startListening();
}

Specifically adapter.startListening(); is listening, because adapter doesn't have a value yet.

And indeed, the rest of the code you shared never creates a FirebaseRecyclerAdapter, so you can't start listening on it. I recommend that you check out the documentation for FirebaseUI, which shows how to create a FirebaseRecyclerAdapter:

 FirebaseRecyclerOptions<Chat> options =
            new FirebaseRecyclerOptions.Builder<Chat>()
                    .setQuery(query, Chat.class)
                    .build();
FirebaseRecyclerAdapter adapter = newFirebaseRecyclerAdapter<Chat, ChatHolder>(options) {
  ...