Single.empty() makes no sense because Single has to have a single item or an error. You could just have kept Observable or switched to Maybe which does allow empty or Completable which doesn’t emit an item at all.
The fluent way is to use Observable.ignoreElements(). Observable.just(1, 2, 3) .ignoreElements() Convert it back via toObservable if needed.
Android Room Exceptions
The difference is that take(1) will relay 0..1 items from upstream whereas first will relay the very first element or emits an error (NoSuchElementException) if the upstream is empty. Neither of them is blocking. It is true first == take(1).single() where take(1) limits the number of upstream items to 1 and single() makes sure upstream … Read more
As stated in the documentation: A small regret about introducing backpressure in RxJava 0.x is that instead of having a separate base reactive class, the Observable itself was retrofitted. The main issue with backpressure is that many hot sources, such as UI events, can’t be reasonably backpressured and cause unexpected MissingBackpressureException (i.e., beginners don’t expect … Read more
Brief introduction of RxJava schedulers. Schedulers.io() – This is used to perform non-CPU-intensive operations like making network calls, reading disc/files, database operations, etc., This maintains a pool of threads. Schedulers.newThread() – Using this, a new thread will be created each time a task is scheduled. It’s usually suggested not to use scheduler unless there is … Read more
Nothing is magic in the life : if you update a value, your Observable won’t be notified. You have to do it by yourself. For example using a PublishSubject. public class Test extends MyChildActivity { private int VARIABLE_TO_OBSERVE = 0; Subject<Integer> mObservable = PublishSubject.create(); protected void onCreate() {/*onCreate method*/ super(); setContentView(); method(); changeVariable(); } public … Read more
I assume you want to clear the BehaviorSubject (because otherwise don’t call onComplete on it). That is not supported but you can achieve a similar effect by having a current value that is ignored by consumers: public static final Object EMPTY = new Object(); BehaviorSubject<Object> subject = BehaviorSubject.createDefault(EMPTY); Observable<YourType> obs = subject.filter(v -> v != … Read more
Yes you are correct. After a stream is terminated ( onComplete / onError has been called ), subscriber unsubscribes automatically. You should be able to test these behaviors using isUnsubscribed() method on the Subscription object.