Android- Pagination for Algolia/Recyclerviews Searches

Algolia a popular SaaS , that provides a service to create a Search API easily and has lightning fast responses is quickly growing and catching up.

Recycler View on the other hand is a concept that helps dynamically create a list from APIs.

To view on recycler view you can see my previous article here

The API part in the previous library used Volley , here we wont be using that as Algolia has it’s own methods to take care of the response.

Like the previous article we create a res file with a Recycler View as below and call the res file activity_main

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout android:layout_height="match_parent"
    android:layout_width="match_parent"
    xmlns:android="http://schemas.android.com/apk/res/android" >
    <android.support.v7.widget.RecyclerView
        android:id="@+id/my_recycler_view"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:scrollbars="vertical" />
    </LinearLayout>

Now in the MainActivity Classs we will initialise the recycler views. We will be using a GridLayoutManager too !

private RecyclerView mRecyclerView;
private RecyclerView.Adapter mAdapter;
private GridLayoutManager gridLayoutManager;

If you are using Algolia then initialise the following too ! But if you are looking for only recycler view and pagination you need not add the following !

Client client;
Index index;
int total_pages;
int nbPage;

Client and Index come from Algolia SDK. You can get the sdk by putting the following under dependencies under the build.gradle of your app

dependencies {
  
    compile 'com.algolia:algoliasearch-android:3.+@aar'
}

Inside the onCreate Method initialize your RecyclerView , Adapters etc

mRecyclerView = (RecyclerView) findViewById(R.id.my_recycler_view);

gridLayoutManager = new GridLayoutManager(this,3);
mAdapter = new movieadapter(movies);
mRecyclerView.setAdapter(mAdapter);
mRecyclerView.setLayoutManager(gridLayoutManager);

mRecyclerView.addOnScrollListener(new EndlessRecyclerViewScrollListener(gridLayoutManager) {
    @Override
    public void onLoadMore(int page, int totalItemsCount) {
        if(isThereMore())
        {
         
            LoadMoreDataFromApi(nbPage);
        }
        else
        {
            Log.e("No more ","data");
        }

    }
});

You can get the EndlessRecyclerViewScrollListener here

If you are using Algolia you might want to initialise your client and index !

Client client = new Client("YOUR_APP_ID", "YOUR_API_KEY");
index = client.initIndex("index name");

Create function called LoadMoreDataFromApi

public void LoadMoreDataFromApi(int page)

{
Query query = new Query("")
    query.setPage(page);


    index.searchAsync(query, new CompletionHandler() {
        @Override
        public void requestCompleted(JSONObject content, AlgoliaException error) {
            try {
                JSONArray jsonArray = content.getJSONArray("hits");
                //Parse the JSON and add in a ArrayList of type your

//model
                nbPage++;//update the current page
              mAdapter.notifyItemChanged(nbPage);


            }
            catch (Exception e)
            {
                e.printStackTrace();
            }
            // [...]
        }
    });

}

Write function called isThereMore() that returns true if more pages are there or false when no more content is there .