Angular, store-select with http get -- [Question Asked]

Query asked by user

i would like to guard a route and do the following:

  • check if user is in ngrx-store
  • if user is in store return true at canActivate
  • if not make an http-get and receicve user
  • if user gets back, store it in store and return true on canActivate
  • if 401, return false

Here is what i got so far:

@Injectable({providedIn: 'root'})
export class AuthGuard implements CanActivate {
  constructor(private authService: AuthService, private router: Router, private store: Store<AppState>) {
  }

  canActivate(route: ActivatedRouteSnapshot, state: RouterStateSnapshot) {
    return this.store.select(selectUser).pipe(
      take(1),
      map(user => {
        if (!!user) {
          return true;
        }

        return this.authService.getUser$()
          .pipe(
            map(user => {
              this.store.dispatch(addUser({user: user}));
              return true;
            })
          )
      })
    );

  }
}

Error:

Type 'Observable<true | Observable<boolean>>' is not assignable to type 'boolean | UrlTree | Observable<boolean | UrlTree> | Promise<boolean | UrlTree>'.

Problem is that return this.authService… returns an Observable which results in
Observable<Observable>.

How can i untie this knot?

Answer we found from sources

        if (!!user) {
          return true; // Returns a boolean - OK
        }

        return this.authService.getUser$()
          .pipe(
            map(user => {
              this.store.dispatch(addUser({user: user}));
              return true; // Returns an observable of a boolean - Not OK
            })
          )

Replace with switchMap :

    return this.store.select(selectUser).pipe(
      first(),
      switchMap(user => {
        if (!!user) {
          return of(true);
        }

        return this.authService.getUser$()
          .pipe(
            map(user => {
              this.store.dispatch(addUser({user: user}));
              return true;
            })
          )
      })
    );

Answered By – temp_user

This Answer collected from stackoverflow, is licensed under cc by-sa 2.5 , cc by-sa 3.0 and cc by-sa 4.0


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