How to call api recursively using rxAndroid until some met condition?

Question

I am using retrofit with rxAndroid, trying to get a response from the server, until server return 0 list size.

getPageAndNext(rows_id), its accept starting point id consider for now its 0 and in next request, I will pass 9th id so that server return after 9th id response.(10th,11th,...15th...19th)

 Observable<List<Feed>> getPageAndNext(int id) {
        return apiInterface.postGetFeed(membersIds, id)
                .flatMap(feedResponse -> {
                    if (feedResponse.getData().size() > 0) {
                        return Observable.just(feedResponse.getData())
                                .concatWith(getPageAndNext(feedResponse.getData().get(feedResponse.getData().size() - 1).getId()));

                    }
                    return Observer::onComplete;
                });

    }

Here per request, I get 10 feeds and insert the feed into room database in onNext method

getPageAndNext(0)
                .subscribeOn(Schedulers.computation())
                .subscribe(new DisposableObserver<List<Feed>>() {
                    @Override
                    public void onNext(List<Feed> feeds) {
                        //save to room database
                        memberDatabaseRepository.insertMemberList(feeds);

                    }

                    @Override
                    public void onError(Throwable e) {
                        Log.e("jjjj", "error"+e);
                    }

                    @Override
                    public void onComplete() {
                        Log.d("kkkk","done");
                    }
                });

Now I am not getting all response from a server. I am searching for the last 24 hours but I didn't get any solution.

Note: I am able to do 76 API calls after that never getting any response even only 76 APIs call data saved in room database. but there is around 630 API calls

Links :-

How To Do Recursive Observable Call in RxJava?

How to ignore error and continue infinite stream?

RxJava takeUntil with emmision of last item?

How to make multiple requests with reactive android and retrofit

score 1 · Accepted Answer · answered May 09 '19 at 11:40

Finally, I solved recursively call API in rxAndroid. takeUntil -> I am checking if I get size zero then stop recursively call.

Observable.range(0, Integer.MAX_VALUE)
                // Get each page in order.
                .concatMap(integer -> {
                    return apiInterface.postGetFeed(membersIds, lastFeedId);
                })
                // Take every result up to and including the one where the next page index is null.
                .takeUntil(result -> {
                    if(!result.getData().isEmpty())
                    lastFeedId = result.getData().get(result.getData().size() - 1).getId();
                    return result.getData().isEmpty();
                })
                .map(FeedResponse::getData)
                .subscribeOn(Schedulers.io())
                .subscribe(new DisposableObserver<List<Feed>>() {
                               @Override
                               public void onNext(List<Feed> feeds) {
                                   Log.d("kkkk", "" + feeds);
                                   memberDatabaseRepository.insertMemberList(feeds, lastFeedId);

                               }

                               @Override
                               public void onError(Throwable e) {
                                   Log.d("kkkk", "error " + e.getMessage());

                               }

                               @Override
                               public void onComplete() {
                                   Log.d("kkkk", "onComplete");
                                   memberDatabaseRepository.getAllFeed(FeedFragment.this);
                               }
                           }
                );

How to call api recursively using rxAndroid until some met condition?

1 Answers1