How would you catch the error

Question

How would you catch the error in that case:

   getStuff(): Observable<Stuff[]> {

    return this.http.get(url)
      .map((res: Response) => {
        return res.json()
        .map(item => {
          return {
            id: item.id
            name: item.code
          };
      });
    });

  }

I tried to put .catch() but saying that return type is not matching Supplied parameters do not match any signature of call target.

getStuff(): Observable<Stuff[]> {

    return this.http.get(url)
      .map((res: Response) => {
        return res.json()
        .map(item => {
          return {
            id: item.id
            name: item.code
          };
      });
    })
    .catch();

  }

with .catch((err) => console.error(err)); getting Argument of type '(err: any) => void' is not assignable to parameter of type '(err: any, caught: Observable<any>) => ObservableInput<{}>'. Type 'void' is not assignable to type 'ObservableInput<{}>'.

@Jerry06 with this one `Argument of type '(err: any) => void' is not assignable to parameter of type '(err: any, caught: Observable) => ObservableInput<{}>'. Type 'void' is not assignable to type 'ObservableInput<{}>'` — Sergino, May 19 '17 at 04:25
The `.catch()` as in `Observable.catch()` is only valid after the initial `.map()`. So `.get().map().catch()` in the observable chain. Yours is in the wrong place. — Neil Lunn, May 19 '17 at 04:27
@NeilLunn I do not think so that it is in the wrong place, it is exactly in the chain `.get().map().catch()` — Sergino, May 19 '17 at 04:41

score 1 · Accepted Answer · answered May 19 '17 at 04:30

1

You can use with Observable.throw

function handleError(error: any) {

  let errorMsg = error.message || `Yikes! There was was a problem `;
  console.error(errorMsg);

  // throw an application level error
  return Observable.throw(errorMsg);
}

And using

 .catch(handleError);

answered May 19 '17 at 04:30

Viet

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this working, but how would you do something like `.catch(throw new MyError())` instead of declaring any additional functions? – Sergino May 19 '17 at 04:44
1

try `.catch(errorMsg => Observable.throw(errorMsg))` – Viet May 19 '17 at 04:50

How would you catch the error

1 Answers1