rxjs

问题 I am using angular 5 and rxjs. I am making 2 service calls, one dependent on others results. I am doing it using flatMap. I am also using takeUntil so that I can abort operation at any given point. My code looks like below: this.myservice.api1(param1).pipe(takeUntil(this.destroyed$), finalize(() => { //do something after both api calls are completed }, flatMap((result1) => { //do some operation and create object x(this.objx) return this.myservice.api2(param1); }) ).subscribe((result2) => { /

问题 I'm working on an Angular project that's throwing an error: core.js:1350 ERROR Error: Uncaught (in promise): EmptyError: no elements in sequence but I can't seem to trace it to any of my app source code. The stack trace all points to rxjs classes. Can anyone tell me how I can debug this error so that I can get to the real error in the code? core.js:1350 ERROR Error: Uncaught (in promise): EmptyError: no elements in sequence EmptyError: no elements in sequence at new EmptyError (EmptyError.js

问题 I'm still a noob when it comes to RxJS but here's a JSBin of what I am trying to do. https://jsbin.com/wusalibiyu/1/edit?js,console I have an observable 'a' (in my case it's the current active connection) which emits a new object whenever the connection reconnects. It's an observable itself because it can re-emit a new value. I now want an observable that completes whenever an action is executed on the current connection. That action notifies it is done when the observable for it completes.

问题 I'm getting the following error: EXCEPTION: Cannot find a differ supporting object '[object Object]' in [files | async in Images@1:9] Here's the relevant part of the template: <img *ngFor="#file of files | async" [src]="file.path"> Here's my code: export class Images { public files: any; public currentPage: number = 0; private _rawFiles: any; constructor(public imagesData: ImagesData) { this.imagesData = imagesData; this._rawFiles = this.imagesData.getData() .flatMap(data => Rx.Observable

问题 Im trying to send data from one component to other using observable. Here I'm implementing observable in service like this... import { Injectable } from '@angular/core'; import { Observable } from 'rxjs/RX' @Injectable() export class SelectedItemService { stream1$:Observable<any>; selectedItem:JSON; stream1$= new Observable(observer=> setTimeout(() => { observer.next(this.selectedItem); }, 3000);) } and my parent Component is initializing data to a service in onselect() like below : import {

问题 I'm currently using this to perform notifications: /** * Create notifications that broacast * the entire set of entries. */ protected notify = new ReplaySubject<E[]>(1); IIUC I can switch out the ReplaySubject<E[]>(1) with AsyncSubject<E[]>() ? Would this be an apple to apple switch or might here be semantic differences? 回答1: No, they're very much not the same. ReplaySubject(1) will always replay the latest emission no matter when the observer subscribes. It can emit any number of times.

问题 Adding a function to Observable to execute when subscribed to (defer) I have an Observable made from events. In this case, Bluetooth notifications. I want to run a function (startNotifictions) only when someone is subscribing to that Observable. This code did work, on previous versions. It is with Ionic3 framework. It added a new operator, that ran when subscribed. Now the transpiler has a problem with the types, complaining twice, that the .doOnSubscribe is not available on typedef

问题 I have an AngularJS component that should react to either a single click or a drag (resizing an area). I started to use RxJS (ReactiveX) in my application, so I try to find a solution using it. The Angular side of the request is minor... To simplify the problem (and to train myself), I made a slider directive, based on the rx.angular.js drag'n'drop example: http://plnkr.co/edit/UqdyB2 See the Slide.js file (the other code is for other experiments). The code of this logic is: function(scope,

问题 Edit: Prior to RxJs 6, tap was called as do . Updated title to reflect tap too. I would like to understand what is the best practice of using .subscribe and .do methods of Observables. For example if I need to do some job after initial data is loaded from server const init$: Observable<MyData> = this._dataService.getData(); init$ .do((initialData: MyData) => { this.data = initialData; // at this step I am initializing the view }) .switchMap(() => loadExtraData) .subscribe((extraData) => {

问题 I'm getting started with RxJs (using the v5 beta), but somehow I can't figure out how to work with distinctUntilChanged . The output from the code below if I run it in babel-node is [ 'a', 1 ] { key: 'a', state: 1 } Next: { value: 42 } Completed That is not what I would expect. Why is only one entry passing distinctUntilChanged ? I would expect the output to be [ 'a', 1 ] [ 'a', 0 ] [ 'a', 1 ] { key: 'a', state: 1 } { key: 'a', state: 2 } { key: 'a', state: 0 } { key: 'a', state: 1 } Next: {