Advertisements I am using combine latest in an angular component to bring together a stream of data with a filter text input: export class RecordSearchComponent implements OnDestroy { @Input() gridData: Observable<TrainingRecord[]> = of([]); private filterSubject = new BehaviorSubject<string>(”); private readonly debounceTimeMs = 300; private filterInput$ = this.filterSubject.pipe( debounceTime(this.debounceTimeMs), distinctUntilChanged(), ) filteredData$ = combineLatest([this.filterInput$, this.gridData]).pipe( tap(([filter,… Read More rxjs using combineLatest to filter data stream – stream data is empty when it should not be

Advertisements How should be go about using / observing parent @Output() event emitters in child components? For example in this demo the child component uses the @Output onGreetingChange like this: <app-greeting [greeting]="onGreetingChange | async"></app-greeting> And this will work if onGreetingChange emits in the AfterViewInit life cycle hook. ngAfterViewInit() { this.onGreetingChange.emit(‘Hola’); } However that produces the… Read More Observing @Output Event Emitters in Child Components?

Advertisements I have created a Confirmation dialog that returns true or false, based on the user’s choice. This is the function that opens the dialog and handles the responses: public action(id: number): void { this.dialogService.openDialog(ConfirmationComponent).afterClosed() .pipe( switchMap( (result: boolean) => { if (result) { return this.service.doSomething(id); } else { return of(‘cancelled’); } } ) ).subscribe({… Read More Subscription after switchMap does not work

Advertisements I have created a Class implementing NestInterceptor(). As it returns an Observable(), when I have a promise in it, it does not wait the promise to return the data. How should I do that? Here is my code: export class PointsInterceptor implements NestInterceptor { intercept(context: ExecutionContext, next: CallHandler): Observable<any> { var monaddress = context.switchToHttp().getRequest().body… Read More How to return a promise in a nestjs interceptor?

Advertisements I am using an observable to retrieve data from an http like: handleError(error:any) { … } getData() { return this._api_service.http.get<JSON>(this._url).pipe(retry(1), catchError(this.handleError)); } loadData() { this.getData().subscribe((data: {}) => { do_something_to_data(data); }); // here I want to do somethings after all the data are loaded do_other_work(); // what should I do here? } It seems do_other_work… Read More How to do things after an observable gets its data in Angular

Advertisements I am trying to bind a variable in a component to the content from an observable in a subscribe() function with an anonymous function: ngOnInit() { this.strSub = this._store.select(selectStr).subscribe((data) => console.log(data)); //this.strSub = this._store.select(selectStr).subscribe((data) => {this.str = data}); } The uncommented line runs fine while the commented line throws an error on compilation Type… Read More Setting a variable in the component from an observable

Advertisements I am trying to get data from observable. In the subscribe() method I can access this data. But to transfer the response to a global variable does not work. How can I do this? Service: getProducts():Observable<IProduct[]>{ return <Observable<IProduct[]>> this.db.collection(‘products’).valueChanges(); } component: products!: IProduct[]; constructor(private dataService: DataService){} ngOnInit(): void { this.dataService.getProducts().subscribe(response => { console.log(response); //… Read More Getting data from observables sync. Angular

Advertisements I’m new to Angular and I’m trying to trigger the error callback in a subscribe. I’m manipulating a table object and want to throw a toast when an trigger becomes true. Either via an error or complete. // editCollection.component.ts handleMoveRowsDown() { this.collectionsStore.moveRowsDown(this.selectedRows).subscribe( (collection) => { this.table.sorts = []; this.rowsSorted = true; this.collection = collection;… Read More Trigger error or complete from a subscribe

Advertisements I created an Observable array of type string. like below products: Observable<string[]>; I want to push some elements into products array. I don’t want to use subscribe methods here. it is not allowing me to use the normal push method. see below code this.products.push("mova"); what is the alternative for the above code(push element to… Read More is it possible to use push() to add element into observable array

Advertisements I am really new to Angular and Typescript. I have this function right now createTranscriptionJob(fileToUpload: File, language: string): Observable<void> { this.getSasUrl(fileToUpload.name, language, ldapUserName) .subscribe(response => { const test = this.upload(response.sasUrl, fileToUpload); console.log(test); }); return of(); } First problem currently is that the createTranscriptionJob function is returning basically nothing. Second problem is that the createTranscriptionJob… Read More Difficulty returning the result of an inner function in Angular / Typescript