notifyDataSetChanged() not working for FirebaseRecyclerAdapter

Question

Deleting items from FirebaseRecyclerAdapter was working fine till I shift to an MVP pattern. right now the adapter is not notifying the change and throwing an error. How can I solve this issue.

Here is my FirebaseRecyclerAdapter,

@Override
    public FirebaseRecyclerAdapter onEntryListChanged(Query query, FirebaseRecyclerOptions<EntryModel> options) {

        adapter = new FirebaseRecyclerAdapter<EntryModel, EntryHolder>(options) {
            @NonNull
            @Override
            public EntryHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
                View view = LayoutInflater.from(parent.getContext())
                        .inflate(R.layout.entry_item_view,parent,false);


                return new EntryHolder(view);
            }

            @Override
            protected void onBindViewHolder(@NonNull final EntryHolder holder, final int position, @NonNull EntryModel model) {
                entryView.attachView(model.getTitle(),model.getContent(),model.getDate(),holder);

                holder.entryUpdate.setOnClickListener(new View.OnClickListener() {
                    @Override
                    public void onClick(View v) {
                        updateFragment(adapter.getRef(position).getKey());
                    }
                });

                holder.entryDelete.setOnClickListener(new View.OnClickListener() {
                    @Override
                    public void onClick(View v) {
                        DatabaseReference mDatabase = FirebaseDatabase.getInstance().getReference("Entry").child(FirebaseAuth.getInstance().getUid());
                        mDatabase.child(adapter.getRef(position).getKey()).removeValue();
                        notifyDataSetChanged();

                    }
                });
                holder.expandArrow.setOnClickListener(new View.OnClickListener() {
                    @Override
                    public void onClick(View v) {
                        boolean shouldExpand = holder.expandContent.getVisibility() == View.GONE;
                        ChangeBounds transition = new ChangeBounds();
                        transition.setDuration(200);

                        if(shouldExpand){
                            entryView.expandArror(holder);
                        }
                        else {
                            entryView.collapsArrow(holder);
                        }
                        entryView.startTransition(holder,transition,shouldExpand);



                    }
                });
            }
        };
        return adapter;

the problem is with the delete.

log file,

07-02 00:38:47.678 29773-29773/com.example.nejat.journalapptrail1 E/AndroidRuntime: FATAL EXCEPTION: main
    Process: com.example.nejat.journalapptrail1, PID: 29773
    java.lang.IndexOutOfBoundsException: Index: 1, Size: 1
        at java.util.ArrayList.get(ArrayList.java:411)
        at com.firebase.ui.common.BaseObservableSnapshotArray.getSnapshot(BaseObservableSnapshotArray.java:70)
        at com.firebase.ui.database.FirebaseRecyclerAdapter.getRef(FirebaseRecyclerAdapter.java:112)
        at com.example.nejat.journalapptrail1.EntryList.EntryListPresenter$1$2.onClick(EntryListPresenter.java:72)
        at android.view.View.performClick(View.java:6261)
        at android.view.View$PerformClick.run(View.java:23752)
        at android.os.Handler.handleCallback(Handler.java:751)
        at android.os.Handler.dispatchMessage(Handler.java:95)
        at android.os.Looper.loop(Looper.java:154)
        at android.app.ActivityThread.main(ActivityThread.java:6776)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1518)

did you implemented onStartListening in your onStart() method ? — Gastón Saillén, Jul 01 '18 at 22:03
yeah, I can view the items properly. I cant only delete them. — Nejweti, Jul 01 '18 at 22:46
Instead of calling `mDatabase.child(adapter.getRef(position).getKey()).removeValue();`, have you tried simply calling: `adapter.getRef(position).removeValue()`? — Rosário Pereira Fernandes, Jul 02 '18 at 00:27

score 0 · Answer 1 · answered Jul 02 '18 at 00:57

you are getting

 java.lang.IndexOutOfBoundsException: Index: 1, Size: 1

you are trying to access Index 1, but you array size is 1, you need access to 0 Index.

try to decrease in 1 your position value for access to correct field in array.

mDatabase.child(adapter.getRef(position-1).getKey()).removeValue();

score 0 · Answer 2 · answered Jul 02 '18 at 05:18

There are a few simple mistakes to fix:

Anywhere you use position, change it to holder.getAdapterPosition(). (To make catching those mistakes easier, remove the final modifier from your position parameter.)
Remove notifyDataSetChanged() calls, this is done for you.

score 0 · Answer 3 · answered Jul 02 '18 at 06:28

It seems you are making mistake in getting the values from the child nodes.

I have fond a sample implementation for FirebaseRecyclerAdapter.

https://github.com/firebase/FirebaseUI-Android/blob/master/database/src/main/java/com/firebase/ui/database/FirebaseRecyclerAdapter.java

I have also tried this and it worked for me.

notifyDataSetChanged() not working for FirebaseRecyclerAdapter

3 Answers3