Guide to sending back an Observable within Angular 4

Question

Guide to sending back an Observable within Angular 4

Inside my authProvider provider class, I have the following method:

retrieveUser() {
    return this.afAuth.authState.subscribe(user => {
        return user;
    });
}

I am looking to subscribe to this method in a different class. Here is an example of how I envision it:

this.authProvider.retrieveUser().subscribe(user => console.log(user));

Any suggestions on how I can modify the retrieveUser() method to return an Observable instead?

angular typescript observable subscriber

Answer 1

Answer №1

To make your authState Observable, you can simply return it as is and then subscribe to it in a separate function. If you need to perform other tasks within that function, consider using the RxJS#map function.

getUser() : Observable {
    return this.afAuth.authState.map(...);
}

....

login() {
   getUser().subscribe(user => {
       return user;
   });
}

Answer 2

To make your authState Observable, you can simply return it as is and then subscribe to it in a separate function. If you need to perform other tasks within that function, consider using the RxJS#map function.

getUser() : Observable {
    return this.afAuth.authState.map(...);
}

....

login() {
   getUser().subscribe(user => {
       return user;
   });
}

Answer 3

Answer №2

Avoid including subscription logic within the getUser function. Instead, simply return the observable.

getUser() {
    return this.afAuth.authState
}

Answer 4

Avoid including subscription logic within the getUser function. Instead, simply return the observable.

getUser() {
    return this.afAuth.authState
}

Answer 5

Answer №3

Here is an example of how you can achieve this. Within your component, the one that needs to utilize this method, you will need to establish a subscription to the provided observable.

fetchUserDetails(): Observable<any> {
    return Observable.create( (observer: Observer<string>) => {
     this.afAuth.authState.subscribe(user => {
        observer.next(user);
    }, (err) => observer.error("error"));
}); 
}

Katie

Answer 6

Here is an example of how you can achieve this. Within your component, the one that needs to utilize this method, you will need to establish a subscription to the provided observable.

fetchUserDetails(): Observable<any> {
    return Observable.create( (observer: Observer<string>) => {
     this.afAuth.authState.subscribe(user => {
        observer.next(user);
    }, (err) => observer.error("error"));
}); 
}

Katie

Answer 7

Answer №4

Ensure to define the return type as an observable

fetchUser(): Observable<DataType> {
    return this.afAuth.authState;
    });
}

Answer 8

Ensure to define the return type as an observable

fetchUser(): Observable<DataType> {
    return this.afAuth.authState;
    });
}

Answer 9

Answer №5

To easily access the function, you can return it directly and then subscribe to it in a different class.

  fetchUser() {
        return this.authService.authState();
  }

Observables can be likened to functions that are invoked upon subscription.

this.userProvider.fetchUser().subscribe(userData => console.log(userData));

Answer 10

To easily access the function, you can return it directly and then subscribe to it in a different class.

  fetchUser() {
        return this.authService.authState();
  }

Observables can be likened to functions that are invoked upon subscription.

this.userProvider.fetchUser().subscribe(userData => console.log(userData));

Guide to sending back an Observable within Angular 4

Answer №1

Answer №2

Answer №3

Answer №4

Answer №5

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