UpcomingMatchesDataSource.java

public class UpcomingMatchesDataSource extends PageKeyedDataSource<Integer, UpcomingMatch> {

    private static final String LOGGER = UpcomingMatchesDataSource.class.getName();

    public static final int PAGE_SIZE = 5;
    private static Integer PAGE_KEY = 0;

    private UpcomingMatchesRepository upcomingMatchesRepository;

    UpcomingMatchesDataSource(UpcomingMatchesRepository upcomingMatchesRepository) {
        this.upcomingMatchesRepository = upcomingMatchesRepository;
    }

    @Override
    public void loadInitial(@NonNull LoadInitialParams<Integer> params, @NonNull LoadInitialCallback<Integer, UpcomingMatch> callback) {
        Log.d(LOGGER, "loading Initial");

        upcomingMatchesRepository.getUpcomingMatches(PAGE_KEY, PAGE_SIZE)
                .subscribe(new Observer<UpcomingMatchesAPIResponse>() {
                    @Override
                    public void onSubscribe(@io.reactivex.annotations.NonNull Disposable d) {
                        Log.d(LOGGER, "onSubscribe of loadInitial");
                    }

                    @Override
                    public void onNext(@io.reactivex.annotations.NonNull UpcomingMatchesAPIResponse upcomingMatchesAPIResponse) {
                        Log.d(LOGGER, "onNext of loadInitial - " + upcomingMatchesAPIResponse.getData().size());
                        List<UpcomingMatch> upcomingMatches = processModelData(upcomingMatchesAPIResponse);
                        callback.onResult(upcomingMatches, null, PAGE_KEY + PAGE_SIZE);
                    }

                    @Override
                    public void onError(@io.reactivex.annotations.NonNull Throwable e) {
                        Log.d(LOGGER, "onError of loadInitial - " + e.getMessage());
                    }

                    @Override
                    public void onComplete() {
                        Log.d(LOGGER, "onComplete of loadInitial");
                    }
                });
    }

    @Override
    public void loadBefore(@NonNull LoadParams<Integer> params, @NonNull LoadCallback<Integer, UpcomingMatch> callback) {
        Log.d(LOGGER, "loading before");
        Integer newKey = (PAGE_KEY > 0) ? PAGE_KEY - PAGE_SIZE : null;
        upcomingMatchesRepository.getUpcomingMatches(params.key, PAGE_SIZE)
                .subscribe(new Observer<UpcomingMatchesAPIResponse>() {
                    @Override
                    public void onSubscribe(@io.reactivex.annotations.NonNull Disposable d) {
                        Log.d(LOGGER, "onSubscribe of loadBefore");
                    }

                    @Override
                    public void onNext(@io.reactivex.annotations.NonNull UpcomingMatchesAPIResponse upcomingMatchesAPIResponse) {
                        Log.d(LOGGER, "onNext of loadBefore");
                        List<UpcomingMatch> upcomingMatches = processModelData(upcomingMatchesAPIResponse);
                        callback.onResult(upcomingMatches, newKey);
                    }

                    @Override
                    public void onError(@io.reactivex.annotations.NonNull Throwable e) {
                        Log.d(LOGGER, "onError of loadBefore - " + e.getMessage());
                    }

                    @Override
                    public void onComplete() {
                        Log.d(LOGGER, "onComplete of loadBefore");
                    }
                });
    }

    @Override
    public void loadAfter(@NonNull LoadParams<Integer> params, @NonNull LoadCallback<Integer, UpcomingMatch> callback) {
        Log.d(LOGGER, "loading after");

        upcomingMatchesRepository.getUpcomingMatches(params.key, PAGE_SIZE)
                .subscribe(new Observer<UpcomingMatchesAPIResponse>() {
                    @Override
                    public void onSubscribe(@io.reactivex.annotations.NonNull Disposable d) {
                        Log.d(LOGGER, "onSubscribe of loadAfter");
                    }

                    @Override
                    public void onNext(@io.reactivex.annotations.NonNull UpcomingMatchesAPIResponse upcomingMatchesAPIResponse) {
                        Log.d(LOGGER, "onNext of loadAfter - " + upcomingMatchesAPIResponse.getData().size());
                        List<UpcomingMatch> upcomingMatches = processModelData(upcomingMatchesAPIResponse);
                        Integer key = (upcomingMatchesAPIResponse.isHasmore()) ? PAGE_KEY + PAGE_SIZE : null;
                        callback.onResult(upcomingMatches, key);
                    }

                    @Override
                    public void onError(@io.reactivex.annotations.NonNull Throwable e) {
                        Log.d(LOGGER, "onError of loadAfter - " + e.getMessage());
                    }

                    @Override
                    public void onComplete() {
                        Log.d(LOGGER, "onComplete of loadAfter");
                    }
                });
    }
}