Recycler view not showing in Activity

Question

I am trying to retrieve some data from Firebase Firestore although I am able to show the data on Logcat window but when I add it into my recycler view it doesn't show, recycler view doesn't inflate. I am unable to figure it out what I am currently missing although code runs without any error.

      private FirebaseFirestore db = FirebaseFirestore.getInstance();
    private CollectionReference sellerRef;

    RecyclerView mRecyclerView;
    List<Products> mProducts;
    Adapter adapter;

    String TAG="MyTag";

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        mRecyclerView = findViewById(R.id.mRecyclerView);
        mProducts=new ArrayList<>();

        GridLayoutManager gridLayoutManager = new GridLayoutManager(this,2,GridLayoutManager.VERTICAL,false);
        mRecyclerView.setHasFixedSize(true);
        mRecyclerView.setLayoutManager(gridLayoutManager);

        adapter = new Adapter(this,mProducts);
        mRecyclerView.setAdapter(adapter);
        adapter.notifyDataSetChanged();



        sellerRef=db.collection("Sellers");
        Query query =sellerRef.whereEqualTo("City_Name","Sydney");
        query.get().addOnCompleteListener(new OnCompleteListener<QuerySnapshot>() {
            @Override
            public void onComplete(@NonNull Task<QuerySnapshot> task) {
                if (task.isSuccessful()){
                    for (QueryDocumentSnapshot document : task.getResult()) {
                        Products products =document.toObject(Products.class);
                        mProducts.add(products);
                        Log.d(TAG,""+products.getCity_Name()+"  "+mProducts.size());
                    }
                }else {
                    Toast.makeText(MainActivity.this, "Failed to load Data", Toast.LENGTH_SHORT).show();
                }
            }
        });


    }
}

Adapter

     private Context mContext;
    private List<Products> mProducts;

    String TAG = "AdTag";

    public Adapter(Context mContext, List<Products> mProducts) {
        this.mContext = mContext;
        this.mProducts= mProducts;
    }

    @NonNull
    @Override
    public Adapter.ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
        View view= LayoutInflater.from(mContext).inflate(R.layout.grid_view_layout,parent,false);
        return new Adapter.ViewHolder(view);
    }

    @Override
    public void onBindViewHolder(@NonNull Adapter.ViewHolder holder, int position) {

        Products products=mProducts.get(position);
        holder.title.setText(products.getCity_Name());

        if (products.getThumbnailUrl().equals("default")){
            holder.gridIcon.setImageResource(R.mipmap.ic_launcher);
        } else {
            Glide.with(mContext).load(products.getThumbnailUrl()).into(holder.gridIcon);
        }

    }

    @Override
    public int getItemCount() {
        return mProducts.size();

    }

    public class ViewHolder extends RecyclerView.ViewHolder{

        public TextView title;
        public ImageView gridIcon;

        public ViewHolder(@NonNull View itemView) {
            super(itemView);
            title=itemView.findViewById(R.id.textView2);
            gridIcon=itemView.findViewById(R.id.imageView2);
        }
    }


}

Answer 1

Call adapter.notifyDataSetChanged(); after update data