angular2-observables

问题 This question already has answers here : Angular 2 View will not update after variable change in subscribe (4 answers) Closed last year . I have a Component-directive that I use to show a div with some information. This component is called SitesComponent and is included in a page. The main behavior of the SitesComponent is fine, except for this: I have an API call to a backend where I return some data, the backend call is executed well and I received the information but the variable is not

问题 I have done this multiple times in my App. It's simple, it should work... But this time it doesn't. My issue: I am calling a method in a service from a Component A, my Component B is subscribed but doesn't react nor receive anything. subscribe() is not triggering! navigation-elements.service.ts @Injectable() export class NavigationElementsService { updateIBOsNavigation$: Observable<any>; private updateIBOsNavigationSubject = new Subject<any>(); constructor() { this.updateIBOsNavigation$ =

问题 Using Angular 4.3.1 and HttpClient, I need to modify the request and response by async service into the HttpInterceptor of httpClient, Example for modifying the request: export class UseAsyncServiceInterceptor implements HttpInterceptor { constructor( private asyncService: AsyncService) { } intercept(req: HttpRequest<any>, next: HttpHandler): Observable<HttpEvent<any>> { // input request of applyLogic, output is async elaboration on request this.asyncService.applyLogic(req).subscribe(

问题 I have a simple scenario: service.ts: private showComposeBoxAction = new BehaviorSubject<boolean>(null); showComposeBox = this.showComposeBoxAction.asObservable(); openComposeBox(event:boolean) { console.log("in openComposeBox"); this.showComposeBoxAction.next(event); } Component.ts: constructor( private _service: Service, ) { this.subscriptions.add( this._mailingService.showComposeBox.subscribe(event => { if (event) { this.displayCompose = true; console.log("showComposeBox displayCompose",

问题 In order to pass value between angular2 different components, I use different services injected into different components. In my PagesService component, I define a behavior subject and want to pass a value. import { Injectable } from '@angular/core'; import { ApiService } from '../../apiService/api.service'; import { Playlists } from '../shared/playlists.model'; import { Subject, BehaviorSubject } from 'rxjs/Rx'; @Injectable() export class PagesService { private currentPlaylists: Subject

问题 I have this structor app/ --pages/ ----pages.component.ts --channel/ ----shared/ ------assignPlaylist.modal.ts Inside the pages.component.ts, I have a variable called playlist export class PagesComponent { @Input() platform: Platform; @Output() onPlaylistsChange: EventEmitter<Playlists>; currentPageName: string; currentPage: Page; pages: Array<Page>; playlists: Playlists; } In assignPlaylist.modal.ts, I make an http post method and it returns a new playlists, I need to use that returned

问题 I am writing angular2 application with interval timers implemented via RxJs observables, and just noticed the strange behaviour of Observable.interval() and Observable.timer() in Chrome browser when tab is in background. Angular component should once every second print number of seconds in console, but on background tabs, this is not working as intended - function triggers every x+1 seconds, where x is interval specified explicitely in the interval funciton Angular component code: ngOnInit()

问题 I have a service that GETS a user via a RESTful api. It uses the Observable implementation. I also have a parent component with 8 child components. I want to know if and how I can make a single HTTP request in the parent component, to get the user and share it amongst its children components. Here's the call to define user in the parent: this.userApi.getUser(id) .subscribe(response => {this.user = response;}, error => error); I've imported and injected the user model into the constructor() of

问题 I need to chain many http requests, the number of request is variable and they are not dependant from the result of the previous one, I just need to keep the returned object of the last request. I've been given two solutions on this thread, the first solution using Observable.concat() works, but a contributor suggested me a more elegant way to perform that, by using concatMap() . Here's my current code : MyComponent submitForms() { var formToSubmit = [...]; // Contains dirty forms that be

问题 I am new to rxjs, so I would like to ask a question regarding Angular 2 , Observables and BehaviorSubject/Subject . So, what I want to achieve is : onclick of a button inside a ComponentA to notify other components for example ComponentB , ComponentC . What I did so far is to create a service : private isMenuOpenBS = new BehaviorSubject(false); toggleMenu(): void { this.isMenuOpenBS.next(!this.isMenuOpenBS.getValue()); } getMenuState(): Observable<boolean> { return this.isMenuOpenBS