CODEWITHSUNDEEP
javaandroidfirebasefirebase-realtime-databaseandroid-recyclerview
Luis Fernando Scripcaru
Luis Fernando Scripcaru

Reputation: 401

Load only x items in Firebase Recycler Adapter

Hi so I have one Firebase FirebaseRecyclerAdapter and in my Firebase project in my database I have over 30 values and in my app I want to display only the first x items.

I searched on internet but I didn't find how I could load only x items.

This is my code:

        mAdapter = new FirebaseRecyclerAdapter<Post, Holder>(
            Post.class,
            R.layout.item_layout,
            Holder.class,
            mRef
    ){

        @Override
        public void onBindViewHolder(Holder viewHolder, int position) {
            Post post = (Post) this.getItem(position);
            ((Holder) viewHolder).bind(post);

        }
        @Override
        public Holder onCreateViewHolder(ViewGroup parent, int viewType) {
            LayoutInflater inflater = LayoutInflater.from(parent.getContext());
            View view;
            view = inflater.inflate(R.layout.item_layout , parent, false);
            return new Holder(view);
        }
 }

This is my holder Class:

public static class EventsOldHolder extends RecyclerView.ViewHolder implements View.OnClickListener {
    public EventsOldHolder(View itemView) {

    }
    public void bind(final Post post) {
    }
    @Override
    public void onClick(View view) {
    }

I know I can hide the elements when position has a higher value than x but if I have a lot of items and hide all of them my app will work slower and if you can help me with a better solution.

Upvotes: 0

Views: 143

Answers (1)

Alex Mamo
Alex Mamo

Reputation: 138824

To solve this, you should pass to the FirebaseRecyclerAdapter constructor a query instead of the mRef, which I assume is a DatabaseReference object.

Assuming that you have a database structure that looks like this:

Firebase-root
    |
    --- posts
          |
          --- postId
                |
                --- title: "Post Title"
                |
                --- //Other details

To display only the first 5 items, the query should look like this:

DatabaseReference rootRef = FirebaseDatabase.getInstance().getReference();
Query query = rootRef.child("posts").orderByChild("title").limitToFirst(5);
query.addListenerForSingleValueEvent(/* ... */);

Upvotes: 1

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