How to handle paging with RxJava?

Question

I\'m looking into converting my android app to use Rxjava for network requests. I currently access a webservice similar to:

getUsersByKeyword(String query, int l         


        

Answer 1

It was hard rock!) So we have request to network:
getUsersByKeyword(String query, int limit, int offset)
and this request return for example
List< Result >
If we use RetroFit for networking that request will look:
Observable< List< Result >> getUsersByKeyword(String query, int limit, int offset)
As result we want to get all Result from server.
So it will look like this

int page = 50;
int limit = page;
Observable
                .range(0, Integer.MAX_VALUE - 1)
                .concatMap(new Func1>>() {
                    @Override
                    public Observable> call(Integer integer) {
                        return getUsersByKeyword(query, integer * page, limit);
                    }
                })
                .takeWhile(new Func1, Boolean>() {
                    @Override
                    public Boolean call(List results) {
                        return !results.isEmpty();
                    }
                })
                .scan(new Func2< List, List, List>() {
                    @Override
                    public List call(List results, List< Result> results2) {
                        List list = new ArrayList<>();
                        list.addAll(results);
                        list.addAll(results2);
                        return list;
                    }
                })
                .last()
                .subscribe(new Subscriber>() {
                    @Override
                    public void onCompleted() {
                    }

                    @Override
                    public void onError(Throwable e) {

                    }

                    @Override
                    public void onNext(List results) {
                    }
                });

Code was TESTED!