I would leverage debounce method decorator like: export function debounce(delay: number = 300): MethodDecorator { return function (target: any, propertyKey: string | symbol, descriptor: PropertyDescriptor) { const timeoutKey = Symbol(); const original = descriptor.value; descriptor.value = function (…args) { clearTimeout(this[timeoutKey]); this[timeoutKey] = setTimeout(() => original.apply(this, args), delay); }; return descriptor; }; } and use it … Read more
Got it: .interval(5000) .startWith(0);
A mapping function takes a thing and returns another thing. e.g. I can build a function that takes 10 and returns 11, that takes 11 and returns 12, etc. const inc = n => n + 1; Array#map applies such mapping function to all elements of an array but “map” doesn’t mean “iteration”. In RxJS, … Read more
I have created a library called ngrx-forms that does exactly what you want. You can get it on npm via: npm install ngrx-forms –save I recommend checking out the full README on the github page, but below you can find some examples of what you need to do to get the library up and running … Read more
Importing has been made easy in RxJS 6: import { merge } from ‘rxjs’; You may want to read the official migration guide. Another useful resource regarding importing in RxJS 6 is this talk by Ben Lesh who is the RxJS lead.
If you want to be sure the order of emissions is the same as the order in which you specified the source Observables you can use concat or concatMap operators. The concat* operators subscribe to an Observable only after the previous Observable completes (it works with Promises as well, see http://reactivex.io/rxjs/class/es6/MiscJSDoc.js~ObservableInputDoc.html). In you case it’d … Read more
Since writing this answer, RxJS version 6 has been released and, in that version, an isObservable function was added to the public API. It can be imported like this: import { isObservable } from “rxjs”; The function signature is: export function isObservable<T>(obj: any): obj is Observable<T> Since it is defined with a typeguard, the compiler … Read more
That’s because forkJoin requires all source Observables to emit at least one item and when there are no source Observables there’s nothing to emit. However, forkJoin will still send the complete notification so you can use for example defaultIfEmpty operator to make sure it always emits at least one next. forkJoin(observables).pipe( defaultIfEmpty(null), ).subscribe(…); Demo: https://stackblitz.com/edit/rxjs-kkd1qa?file=index.ts
forkJoin emits only when all inner observables have completed. If you need an equivalent of forkJoin that just listens to a single emission from each source, use combineLatest + take(1) combineLatest( this.statuses$, this.companies$, ) .pipe( take(1), ) .subscribe(([statuses, companies]) => { console.log(‘forkjoin’); this._countStatus(statuses, companies); }); As soon as both sources emit, combineLatest will emit and … Read more
I’m still getting my head round 5.5 but it looks like now instead of importing throw use ErrorObservable. // import { _throw } from ‘rxjs/observable/throw’; import { ErrorObservable } from ‘rxjs/observable/ErrorObservable’; ErrorObservable.create(‘error’); From this guide it looks like it has to be _throw to avoid a keyword clash (the rest of the video is good … Read more