How to return a promise inside Observable subscriber angular 8

Question

I am working on an angular 8 project and I need to return a promise inside a subscribe. Here is my observable:

export async function resolvePage(api: ApiService, transition: Transition) {
    const slug = transition.params().slug.split('/').slice(-1).pop();
    return api.get(`/pages/${slug}`).toPromise();
}

And I need to do something like this, but it doesn't work:

export async function resolvePage(
  api: ApiService,
  transition: Transition,
  stateService: StateService
) {
  const slug = transition
    .params()
    .slug.split("/")
    .slice(-1)
    .pop();
  return api.get(`/pages/${slug}`).subscribe(
    (res: any) => {
      return new Promise((resolve, reject) => {
        resolve(res);
      });
    },
    () => {
      stateService.go("app.404");
    }
  );
}

How can I do it?

`return api.get(...).toPromise()` but this undermines the benefits of using observables. — Reactgular, Dec 16 '19 at 19:46
"Here is my observable:" What you show there is not an observable, but a promise... — Heretic Monkey, Dec 16 '19 at 20:04
Can you return the resolve method - ' {return resolve(res)}' ? — RajuPedda, Dec 16 '19 at 20:06
If you just want to use async/await, see [Is it a good practice using Observable with async/await?](https://stackoverflow.com/q/49596641/215552) You may want to read [What are the differences between observables and promises in JavaScript?](https://stackoverflow.com/q/56834905/215552) in addition. — Heretic Monkey, Dec 16 '19 at 20:12

score 1 · Answer 1 · edited Dec 16 '19 at 19:52

1

You can use Observable.toPromise() method. See https://www.learnrxjs.io/operators/utility/topromise.html

edited Dec 16 '19 at 19:52

maury844

1,210
15
25

answered Dec 16 '19 at 19:45

Petia Biloshytsky

126
6

How to return a promise inside Observable subscriber angular 8

1 Answers1