The Reactive Extensions for JavaScript is a set of libraries to compose asynchronous, resilient and responsive event driven programs using observable collections with ECMA Script5 Array#extras style composition in JavaScript.
Questions tagged [reactive-extensions-js]
121 questions
1
vote
2 answers
Reactive Extensions: How to create a placeholder observable?
I have a method, getObs(), that returns an observable, which should be shared by all callers. However, that observable might not exist when somebody calls getObs(), and creating it is an async operation, so my idea was to return a placeholder…
Egil Hansen
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1
vote
1 answer
Catch circular dependency between observables
I have a user-programming scenario where user can end up creating two observables that depend on each other. RxJS does not allow circular dependencies, as far as I can see, the memory or stack reaches its limits and the onError callback is triggered…
Egil Hansen
- 15,028
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1
vote
1 answer
SignalR and Reactive combo
I found this little gem about how to get SignalR and Rx to play nicely:
Rx and Reactive Tutorial
However as you might have noticed this only works when going from server -> client. Does anyone know how to go the other way around? I want my framework…
Alwyn
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1
vote
1 answer
I need to visualize a dynamic collection with JavaScript, can it be implemented with Reactive Extensions?
I am writing this Web application where I need to visualize filtered, sorted and paginated (on the server) collections through JavaScript (planning on using Isotope to present collections). These collections are dynamic, i.e. they start out with…
aknuds1
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1
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0 answers
rx javascript periodic event ignore until handled first
maybe I missed purpose of RX for javascript library, but I think it should handle this scenario nicely.
I would like to have periodic events generated through observable. Subscriber should take first event and make ajax request. Other events while…
dieselcz
- 433
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0
votes
2 answers
Using one subject to propagate completly different event streams through
I need to proxy all the different event streams through one subject.
I came up with this code:
var mySubject,
getObservable;
getObservable = function (subject, eventName) {
return subject
.asObservable()
.filter(function (x)…
Christoph
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0
votes
1 answer
Rx Publish() breaks IObservable of XDocuments
I have the following Rx Query that produces a IObservable problem is it does not work with Publish() so as the number of subscribers increases so does the memmory load
// Works
Observable
.Interval(TimeSpan.FromSeconds(1.0))
.Select(_ =>…
Madu Alikor
- 2,544
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0
votes
1 answer
Multiple asynchronous public API calls (rails+node.js or reactive js)
I'm trying to make non-blocking calls to 3 public APIs, i.e website A,B,C and then forward the results back to the rails app as JSON datas. I asked if this is possible in node.js on another forum and it seems it is and someone pointed me to this…
Benny Tjia
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0
votes
1 answer
How to implement server polling in rxjs
I have a very simple server polling scenario:
call API -> 2. onSuccess -> 3. wait 500ms -> 4. go back to step 1
and
call API -> 2. onError -> 3. finish
I want to be using rxjs as I already use rxjava. But I just can't seem to arrive on a…
SMGhost
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0
votes
1 answer
Angular BehaviorSubject; the "next" method doesn't work
I have a code that I wrote back in Angular 4 and it worked perfectly, now part of it is broken in Angular 6 and I appreciate some help.
I have an AuthService class:
export class AuthService {
private loggedIn = new…
Behrooz
- 1,895
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0
votes
1 answer
Making an observable 'run' synchronously
I have a situation in which I need to wait for the observable to begin emitting values before the subsequent code executes. The closest I have gotten so far is like this:
async ensureContentLoaded() {
if (!this.content) {
defer(async () => {
…
serlingpa
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0
votes
0 answers
How delayWhen works in observables?
I am bit confused with Rxjs.
I am trying to implement timer counter using observable.
Below is link
https://jsfiddle.net/vpx0y8fu/375/
Consider below code snippet i have message as source which emits value after 1 sec. I have used delayWhen operator…
Shirish
- 69
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0
votes
1 answer
RxJS - concatenate mapped elements onto a stream
Is there is an operator which allows me to map over elements of a stream but instead of transforming them, concatenating them?
I have a stream
A => B => C
items$.concatMap(x => f(x))
would lead to
"f(A)" => "f(B)" => "f(C)"
while concat does not…
ᴘᴀɴᴀʏɪᴏᴛɪs
- 7,169
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- 81
0
votes
2 answers
RxJS - Buffer unique values and emit when no other values have been emitted for x seconds?
A user is typing values in a form and an event is emitted every time a user edits a particular field, with the value being the field they edited.
For example a user typing 3 times into the description field, followed by two times in the name field,…
ᴘᴀɴᴀʏɪᴏᴛɪs
- 7,169
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- 81
0
votes
1 answer
How can I create an eager observable from a hot observable?
AFAIK, observable is lazy.
import * as rxjs from 'rxjs'
const { filter, take, map } = rxjs.operators
function awesomeOpators() {
return take(1);
}
const numbers$ = new rxjs.Subject();
const start$ = numbers$.pipe(
…
Zen
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