rxjs

问题 I'm having a hard time making distinctUntilChanged work in this next scenario. I made an asynchronous validator, which uses a service to check if a user exists with the given username. This validator is bound, as a directive, to an input. class ValidateUniqueUsernameDirective implements AsyncValidator { constructor(private userService: UserService) {} validate( control: AbstractControl ): Promise<ValidationErrors> | Observable<ValidationErrors> { return control.valueChanges.pipe( debounceTime

问题 const placeId = this.getPlaceId(); this.af.database.list(`placeUsers/${placeId}`).subscribe((userKeys) => { for (let index = 0; index < userKeys.length; index++) { let userKey = userKeys[index]; this.af.database.list(`userDevices/${userKey.$key}`).subscribe((deviceKeys) => { for (let index = 0; index < deviceKeys.length; index++) { let deviceKey = deviceKeys[index]; this.af.database.object(`devices/${deviceKey.$key}`).subscribe((device) => { console.log(device); // Device received. }); } });

问题 For example: this.saveSubscription$ = this.ds.onSave$.subscribe(x => this.sb.updateMachineTool(this.viewEditModel.viewEditModel).subscribe(x = { console.log('alert results', x) }) ) this.ds.onSave$ is a subject that triggers when a save button on a different component is clicked. this.sb.updateMachineTool is an httpClient post that updates a specific tool should I be using some type of map so i'm not subscribing to both areas? How can I refactor this code? 回答1: To Refactor your code You can

问题 I am talking to some RESTful search endpoint that involves pagination. The query is triggered by user typing in a search field, and as a result it produces an Observable with N values, corresponding to the N result pages. The code looks somewhat like the following: function runQueries(queryObservable) { return queryObservable .debounceTime(500) .distinctUntilChanged() .switchMap(search); } function search(query) { return Observable.create(observer => searchInto(observer, query, 0)); }

问题 I have migrated from angular 5 to Angular 7. After that I have a problem with my RxJs operation like observable and my @ngrx/store. Here is my error: ERROR in node_modules/@ngrx/store/src/actions_subject.d.ts(2,10): error TS2305: Module C:/Users/AbousyllabaNdiaye/Documents/amundi/ClientAmundiFileIntegration/node_modules/rxjs/BehaviorSubject"' has no exported member 'BehaviorSubject'. node_modules/@ngrx/store/src/reducer_manager.d.ts(2,10): error TS2305: Module '"C:/Users/AbousyllabaNdiaye

问题 I have a timer that periodically pumps data into the main page of my Angular4 app. For Chrome, everything is working just fine. However, IE11 will sometimes get into a mode where the Observable, and actually even the Observables that are not on a timer (on other pages), will pump out old data. While Chrome is going along just fine getting new data, IE is stuck with numbers it had from a period of time in the past. When I navigate to other pages, everything is stuck in the past, so all the

问题 I'm trying to use Rx.js to handle the flow of Chrome extension webrequest API. Each webrequest addListener() call takes a mandatory callback function as the first parameter. This sends request objects to the function. However, the callback can return a webRequest.BlockingResponse that determines the further life cycle of the request. I'm struggling to handle the blocking response as part of the observable. This code works well for examining all image requests, for example

问题 Is it possible to post multipart/form-data with RxJS Ajax observable? I tried to do so by setting Content-Type in ajax settings object like so. import { ajax } from 'rxjs/observable/dom/ajax'; let data = { ad = 'ad_id', image = <HTML5 File object> } let settings = { url: '/some-url', body: data, method: 'post', headers: { 'Content-Type': 'multipart/form-data; boundary=---------2e50046', ... } ... } And used ajax(settings) to post the form However, it does not seem to work when sent to backend

问题 I'm getting an array of objects as a HTTP response and I'm trying to group them by a value in the object. As an example let's say I get the following: [ {player: 'Jordy Nelson', team: 'Packers'}, {player: 'Aaron Rogers', team: 'Packers'}, {player: 'Dak Prescott', team: 'Cowboys'}, {player: 'Ezekiel Elliot', team: 'Cowboys'}, {player: 'Joe Flacco', team: 'Ravens'}, {player: 'Julio Jones', team: 'Falcons'}, ] I'm trying to take that response and convert it to an array of objects, containing an

问题 I'm trying to create an Rx.Observable from a chain of Promises with RxJS. The difference from this question is that I have unknown number of Promises, and every Promise depends on the result of the previous one. Basically I have a sequence of pages, connected with "next page" links. What I want the function to do is: Wait for Promise<> Provide the result (fire observer.onNext()) Check if there is a next page link Create next Promise<> with that link Repeat until there are pages remained I