rxjs

问题 in service section of angular.io tutorial for angular2 I hit a method named of.for example : getHeroes(): Observable<Hero[]> { return of(HEROES); } or in below sample: getHero(id: number): Observable<Hero> { // Todo: send the message _after_ fetching the hero this.messageService.add(`HeroService: fetched hero id=${id}`); return of(HEROES.find(hero => hero.id === id)); } in angular.io Just explained used RxJS of() to return an Observable of mock heroes (Observable). and It was not explained

问题 According to this artcle, onComplete and onError function of the subscribe are mutually exclusive. Meaning either onError or onComplete events will fire up in my subscribe . I have a logic block which needs to be executed whether I receive an error, or I finish my steam of information successfully. I looked up for something like finally in python, but all I found is finally which needs to be attached to the observable I create. But I want to to do that logic only when I subscribe, and after

问题 This is a followup for this question. So RxJS is calling my async function with the next event bebore the previous one has completed as soon as I await in my async method. I need to serialize the calls to this async function. I have understood from this answer to a similar question that I need to move my async function away from subscribe and use concatMap. Right now my code does not compile with the following error: error TS2339: Property 'concatMap' does not exist on type 'Observable'. My

问题 I have 3 streams. gradingResult and contextId depend on studentResponse . I need to fire an event and only one event (otherwise, this is trivial) when all 3 have the latest values. I've tried #combineTemplate and #sampledBy studentResponse . Unfortunately, I always see the wrong data--- gradingResult and contextId have the old values in the combined template. How can I wait for all streams to have the latest values? Code is shown below: var studentResponse = new Bacon.Bus(); var gradingResult

问题 I have a component that has two properties that are observables @Component({ }) export class MyComponent { observable1$; observable1$; ngOnInit() { Observable1$ = this.service.getObservable1(); Observable2$ = this.service.getObservable2(); } } I practice, observable2$ will emit bar only after observable1$ emits foo . How can I write a test that simulates this? If I write in my spec mockService.getObservable1.and.returnValue(Observable.of('foo')) mockService.getObservable2.and.returnValue

问题 I had an app initiating course components like this: <li *ngFor="let course of courses"> <app-course [appCourse]="course" (remove)="removeItem($event)" ></app-course> </li> from an array pulled from local storage, which was populated from a course form, sending an object like this: { "_id": "587f52ad266c32fbfb10f21a", "end": "31/1/2017", "start": "1/1/2017", "desc": "see title", "name": "Intro To Express", "id": 1, "__v": 0, "updated_at": "2017-01-18T11:34:05.416Z" } Then I added a back end

问题 I am very confused on integrating Firebase with ngrx/store. Since Firebase has socket based "live" update, so the store data is already sync with Firebase data whenever I update Firebase. The problem is, I do not know how to listen to Firebase update and trigger a side effect with effect/store to do some more update on Firebase and the client store. Any suggestion on how should I approach this problem. For now, I have to use a long pull Observable.interval(5000) strategy to trigger a service

问题 I am very confused on integrating Firebase with ngrx/store. Since Firebase has socket based "live" update, so the store data is already sync with Firebase data whenever I update Firebase. The problem is, I do not know how to listen to Firebase update and trigger a side effect with effect/store to do some more update on Firebase and the client store. Any suggestion on how should I approach this problem. For now, I have to use a long pull Observable.interval(5000) strategy to trigger a service

问题 I am very confused on integrating Firebase with ngrx/store. Since Firebase has socket based "live" update, so the store data is already sync with Firebase data whenever I update Firebase. The problem is, I do not know how to listen to Firebase update and trigger a side effect with effect/store to do some more update on Firebase and the client store. Any suggestion on how should I approach this problem. For now, I have to use a long pull Observable.interval(5000) strategy to trigger a service

问题 I am using ap-fullcalendar for angular/typescript. I have a data service, where I get the events for the calendar from my database, I wrap the data in a Behaviour Subject and subscribe to it and make it into an observable from another function. I have a data service because I have multiple subscriptions to the same observable. In my component where the calendar is, I subscribe to the data. However, for some reason, the events are not getting passed properly to the calendar and won't show up.