Angular 6: Property 'catch' does not exist on type 'Observable'?

问题

I am upgrading my app to Angular 6. I am upgrading from Angular 4, but the code below is causing errors in Angular 6, where it worked fine in Angular 4.

The errors I am getting:

Property 'of' does not exist on type 'typeof Observable'

Error: Property 'catch' does not exist on type 'Observable'

How should I resolve these errors?

  private authInterceptor(observable: Observable<Response>): Observable<Response> {
    return observable.catch((error, source) => {
      if (error.status == 401) {
        this.router.navigateByUrl('/login');
        return Observable.of();
      } else {
        return Observable.throw(error);
      }
    });
  }

回答1:

Since you tagged your question rxjs6, I'm assuming the upgrade to Angular 6 includes an upgrade to rxjs6. In that case, it's not working because methods on the observable object are now standalone operators that you can apply using pipe(). Also, imports have changed. See the migration guide for more details.

With rxjs6 it should look something like this:

import { Observable, EMPTY, throwError } from 'rxjs';
import { catchError } from 'rxjs/operators';

private authInterceptor(observable: Observable<Response>): Observable<Response> {
   return observable.pipe(
       catchError( err => {
            if (err.status == 401) {
                this.router.navigateByUrl('/login');
                return EMPTY;
            } else {
                return throwError(err);
            }
       })
   );
 }

回答2:

import 'rxjs/add/operator/catch';

Or import Observable this way:

import {Observable} from 'rxjs';

回答3:

I am assuming you have migrated to RXJS6 since you have also migrated to angular6.

In RXJS6 use catch Error instead of catch as seen here

  import {catchError } from 'rxjs/operators';
  import { Observable, of } from 'rxjs';

回答4:

Import the Library with following method and rearrange the code

import { catchError } from 'rxjs/operators';
return Observable.pipe(catchError =>...);

This worked for me.

回答5:

Need to import the catch operator

import 'rxjs/add/operator/catch';

回答6:

you will need to import all operators you are using.

import 'rxjs/add/observable/of';
import 'rxjs/add/observable/throw';
import 'rxjs/add/operator/catch';

回答7:

This worked for me, I'am using Angular 6.1.0.

import { Observable, Subject, of } from 'rxjs';
import { switchMap, debounceTime, distinctUntilChanged, catchError } from 'rxjs/operators';

this.ofertas = this.subjectPesquisa // Retorno Oferta[]
  .pipe(debounceTime(1000)) // Executa a ação do switchMap após 1 segundo
  .pipe(distinctUntilChanged()) // Apenas executa a ação switchMap se o termo enviado for outro
  .pipe(switchMap((termo: string) => {

    if (termo.trim() === '') {
      // Retornar um observable de array de ofertas vazio.
      return of<Oferta[]>([]);
    }

    console.log('Requisição HTTP para api: ', termo);
    return this.ofertasService.pesquisaOfertas(termo);
  }))
  .pipe(catchError((err: any) => {
    console.log('Erro: ', catchError);
    return of<Oferta[]>([]);
  }));

来源：https://stackoverflow.com/questions/50967309/angular-6-property-catch-does-not-exist-on-type-observableresponse

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