rxjs

问题 I'm borrowing some code from this stackoverflow: Angular window resize event The author of the answer says I should be using the EventManager if I want to listen for window events from a service and not break Angular Universal. That being said, is this answer still true? If so, could someone show me why when I subscribe to the onResize$ Observable logs nothing when the window is resized? import { EventManager } from '@angular/platform-browser'; import { Observable } from 'rxjs/Observable';

问题 I have a complex calculator app written in Angular6 which calculates the results based of several inputs in the ngModelChange event and to show these results in charts directly. The calculation is done server side. Now I want to add a debouncetime, so the server dont receive a request with every key pressed. My calculation method which is fires in the ngModelChange looks like this: async calculate(){ if(this.checkInputs()){ try{ let returnDto = await this.webApiService.calculate(new

问题 I have the following motion equations move = target_position - position position = position + move where target_position is a stream and position is initialized at zero. I would like to have a stream of position. I have tried something like this (in rx pseudo code) moves = Subject() position = moves.scan(sum,0) target_position.combine_latest(position,diff).subscribe( moves.on_next) It works but I have read that using Subject should be avoided. Is it possible to compute the position stream

问题 I am using rxjs 6 I have two observables in my code import { combineLatest } from 'rxjs/operators'; loading$: Observable<boolean>; loaded$: Observable<boolean>; The observables are not coming from http request but from the store I need to combine/convert the sequences in to one single observable value based on this logic: If the sequence true , true or false , false - need to return new observable true otherwise need to return false I tried to use combineLatest to achieve that: combineLatest(

问题 I am using RxJs in an Angular 2 application to fetch data from an API for multiple pages in parallel and save any failed requests for future re-try. To do so, I want to catch errors generated by flatMap-ing http get requests (code below) and continue with further stream processing. In case of error, my current solution causes stream to discontinue. Rx.Observable.range(1, 5) .flatMap(pageNo => { params.set('page', ''+pageNo); return this.http.get(this.API_GET, params) .catch( (err) => { //save

问题 I have the following HttpClient.post call which return an array of Objects. import { map } from 'rxjs/operators/map'; public getArray(profileId: number): Observable<any> { return this.http.post("/api/url", postObject, HttpSettings.GetDefaultHttpRequestOptions()) .pipe(map(data => { console.log(data); // logs (2) [{…}, {…}] return data; })); } I need to Instantiate an Array of objects. I can't just type assert because I need the Thing constructor to parse some json and other. Essentially what

问题 I have a simple interceptor that handles requests and catches any http error using RXJS catchError. The second argument received in catchError is the caught observable. I want to, in some cases, return this error and let it propagate up to the error handler in the subscribe function. The problem is that returning th caught error causes an infinite loop (as seen in the example: https://stackblitz.com/edit/angular-u4gakr) The intercept function in the interceptor where the catchError is stuck

问题 Here, I've used forkJoin from rxjs to subscribe to an array of observables parallelly. But I want to subscribe to them one by one, What will be the best solution? Below is my code : var observables = []; Observable.forkJoin(observables) .subscribe(() => { this.msgs = []; this.msgs.push({ severity: 'success', summary: 'Saved Successfully' }); this.onSaveComplete(); }, (error: any) => this.errorMessage = <any>error); }, (error: any) => this.errorMessage = <any>error); 回答1: Alternate of forkJoin

问题 I am in process of redux-observable learning, and I have some doubts: Should we create an Epic for each action to watch? export const actionEpic = action $ => action$.ofType('ACTION') export const action2Epic = action $ => action$.ofType('ACTION2') Or can we create it for many like reducers with switch? import every single Epic to convine in the middleware is a lot of work 回答1: A large majority of epics will begin by matching a single action, e.g. action$.ofType(SOMETHING) . This is because

问题 This page says "toPromise has been deprecated! (RxJS 5.5+)" but I've been using it lately with AngularFire2 (when I only want one result) like this: const foo = await this.afs.doc(`docPath`).valueChanges().toPromise(); Should I not be doing this? If not, what is the await alternative? UPDATE: After the answer below I've changed this: const foo = await this.afs.doc(`docPath`).valueChanges().toPromise(); ...to this: const foo = await (new Promise(resolve => this.afs.doc(`docPath`).valueChanges(