CODEWITHSUNDEEP
rx-java2
surik
surik

Reputation: 25

Unexpected return value error in RxJava2

Need help to resolve issue with return value in RxJava. So, here is what I have done so far:

private Observable<Boolean> updatedMenuItems() {
    return Observable.fromIterable(getAliases())
        .doOnNext(alias -> {
            return ApiRepository.getMenuItemBlocks(alias)
                    .subscribeOn(Schedulers.io())
                    .flatMapIterable(list -> list)
                    .map(item -> item.getFileTimeStamp() == null ? "" : item.getFileTimeStamp().toString())
                    .toList()
                    .doOnSuccess(apiContents -> {
                        return Observable.fromCallable(DataStoreRepository::loadMenuItemsBlock)
                                .subscribeOn(Schedulers.io())
                                .flatMapIterable(list -> list)
                                .map(item -> item.fileTimeStamp == null ? "" : item.fileTimeStamp.toString())
                                .toList()
                                .map(dbContents -> {
                                    return DBUtil.isContentEqual(dbContents, apiContents);
                                });
                    });

        });
}

I need to return Observable<Boolean> data type from this method but inside the block of .doOnSuccess(...); I am getting an error concerning return value. Could you please, help me to solve this issue. Thanks!

Upvotes: 0

Views: 560

Answers (1)

Ahmed Ashraf
Ahmed Ashraf

Reputation: 2835

doOnNext, doOnSuccess, doOnError, doOnCompleted

These are called Side-effect operators, they don't really affect the chain in anyway, they might be used as a logging mechanism for ex.

What you're looking for is probably flatMap, from the docs:

FlatMap: Transforms the items emitted by an Observable into Observables, then flatten the emissions from those into a single Observable.

Upvotes: 1

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