reactive-programming

I would like to chain Mono s and emit the first non-empty of them. I thought the or() operator was designed for this purpose. Here is my chain of Mono s: first one is empty and second one should emit "hello". @Test void orTest() { Mono<String> chain = Mono.<String>empty().or(Mono.just("hello")); StepVerifier.create( chain ) .expectNext("hello") .verifyComplete(); } However, I get the following failure: java.lang.AssertionError: expectation "expectNext(hello)" failed (expected: onNext(hello); actual: onComplete()) Can someone please help? What I am getting wrong here? You misunderstand or() -

I'm trying to implement a version of this intro to RxJS ( fiddle here ) that instead of picking a random object from a returned API array, it consumes a backthrottled stream of objects from the returned API array. Here's a portion of the code that produces a controlled Observable from the API response (full fiddle here ): var responseStream = requestStream.flatMap(function (requestUrl) { return Rx.Observable.fromPromise(fetch(requestUrl)); }).flatMap(function(response) { return Rx.Observable.fromPromise(response.json()); }).flatMap(function(json) { return Rx.Observable.from(json); })

I am pretty new to React-Native. I install react-native on my Mac using the code below: npm install react-native -g react-native-cli I got the error: npm ERR! code MODULE_NOT_FOUND npm Err! Cannot find module 'minizlib' Anyone can help me to solve this problem please? New to this myself as a disclaimer but you may want to try uninstalling node. If you installed node with Homebrew try... $ brew uninstall node $ brew install node Try this brew install node brew install watchman npm install -g react-native-cli react-native init AwesomeProject Follow the exact steps in https://facebook.github.io

I am using RxJava to process some notifications that we pull from a queue. RxJava seemed to work fine with a simple workflow, now with new requirements coming in, the flow is growing in complexity with more branches (please see below picture as a reference) I tried to exemplify the flow with a small unit test: @Test public void test() { Observable.range(1, 100) .groupBy(n -> n % 3) .toMap(GroupedObservable::getKey) .flatMap(m1 -> { Observable<Integer> ones1 = m1.get(0); Observable<Integer> twos1 = m1.get(1).map(n -> n - 10); Observable<Integer> threes = m1.get(2).map(n -> n + 100); Observable

How can I map one occurred exception to another one in RxJava2? For example: doOnError(throwable -> { if (throwable instanceof FooException) { throw new BarException(); } }) In this case I finally receive CompositeException that consists of FooException and BarException , but I'd like to receive only BarException . Help! You can use onErrorResumeNext and return Observable.error() from it: source.onErrorResumeNext(e -> Observable.error(new BarException())) Edit This test passes for me: @Test public void test() { Observable.error(new IOException()) .onErrorResumeNext((Throwable e) -> Observable

Reading How to use RxJs distinctUntilChanged? and this , it seems that distinctUntilChanged alters the output stream to only provide distinct contiguous values . I take that to mean that if the same value arrives in immediate succession, you are essentially filtering the stream and only getting one occurrence of that repeated value. So if I write this: this.myFormControl.valueChanges .debounceTime(1000) .distinctUntilChanged() .subscribe(newValue => { console.log('debounced: ', newValue); }); I see no difference in output to this: this.myFormControl.valueChanges .debounceTime(1000) .subscribe

I'm using RxJS here and I can't seem to get over this seemingly simple issue. rx.Observable .from([1,2,3,54,3,22,323,23,11,2]) .distinct() .subscribe(function next (x) { console.log('Next'); console.log(x); }, function error (x) { console.log('Error'); console.log(x); }, function completed () { console.log('Completed'); }); The above code spits out each array item in order as expected. rx.Observable .fromPromise(getNumbers([1,2,3,54,3,22,323,23,11,2])) .distinct() .subscribe(function next (x) { console.log('Next'); console.log(x); }, function error (x) { console.log('Error'); console.log(x); }