How to avoid nested subscription - rx-java2

Question

I have this method deleteFeedTable() which returns a Completable and when it finishes I want to start another Disposable.
What I did is combine the two using operator concatWith, but this results in a nested subscription and I'd like to avoid that.
disposables.add(
localDataSource.deleteFeedTable()
.doOnComplete(() -> { preferencesManager.setFeedTableUpdateState(false);
})
.concatWith(new Completable() {
#Override
protected void subscribeActual(CompletableObserver s) {
s.onSubscribe(localDataSource.getLastStoredId()
.flatMap(lastStoredId -> remoteDataSource.getFeed(lastStoredId))
.doOnNext(feedItemList -> localDataSource.saveFeed(feedItemList))
.map(feedItemList -> {
Timber.i("MESA STO MAP");
List<Feed> feedList = new ArrayList<>();
for (FeedItem feedItem : feedItemList) {
feedList.add(mapper.from(feedItem));
}
downloadImageUseCase.downloadPhotos(feedList);
return feedList;
})
.subscribe());
}
})
.subscribeOn(schedulerProvider.io())
.observeOn(schedulerProvider.mainThread())
.subscribe(() -> {}, throwable -> Log.i("THROW", "loadData ", throwable)));
Is there a way I can avoid the nested subscription ? Or is there another way to add it to the disposables variable so I can clear the subscription later ?

Answer 1

Use andThen:
disposables.add(
localDataSource.deleteFeedTable()
.doOnComplete(() -> {
preferencesManager.setFeedTableUpdateState(false);
})
.andThen(
localDataSource.getLastStoredId()
.flatMap(lastStoredId -> remoteDataSource.getFeed(lastStoredId))
.doOnNext(feedItemList -> localDataSource.saveFeed(feedItemList))
.map(feedItemList -> {
Timber.i("MESA STO MAP");
List<Feed> feedList = new ArrayList<>();
for (FeedItem feedItem : feedItemList) {
feedList.add(mapper.from(feedItem));
}
downloadImageUseCase.downloadPhotos(feedList);
return feedList;
})
)
.subscribeOn(schedulerProvider.io())
.observeOn(schedulerProvider.mainThread())
.subscribe(() -> {}, throwable -> Log.i("THROW", "loadData ", throwable)));