rxjs firstValueFrom() 从不取消订阅 observble

Question

Greatings,

I'm struggling with the firstValueFrom(), lastValueForm() and even Observable.pipe(take(1))...

I'm coding in type script with Angular 14 and RxJs 7.8.0. My server is a firebase server which provide stored image url via an API with a getDownloadUrl function as an Observable.

What I want to do is download my url one time so I can display the image.

Whenever I try one of this method on my Observable it never unsubscribe so the Observable emit value infinitely.

I tried to write it with async/await syntax and also with the promise syntax but still not able to make it unsubscribe after the first emission.

I can't actually find any reason why it doesn't work... Can some one help me?

returnImage(ref: string){
  return new Promise((resolve,reject)=>{
    firstValueFrom(this.fireStorage.ref(ref).getDownloadURL()).then((url)=>{
      console.log(url);
    },(error)=>{
      reject(error);
    });
  });
}

enter image description here

What I want to do is download my url one time so I can display the image.

Whenever I try one of this method on my Observable it never unsubscribe so the Observable emit value infinitely.

alreeady try to upgrade rxjs. I was using 7.5.0 but upgraded it to 7.8.0.

I tried to write it with async/await syntax and also with the promise syntax

Answer 1

Thank you very much for your answers it helped me a lot.

1 _ @konrad put me on the way with his questions: I forgot to unsubscribe to my database observable which emit datasnapshot regularly. I display data on my DOM from this observable and use a function to download image at the right time. So I think the different syntaxes I tried were right but they were called many time by each datasnapshot emission...

2 _ @Shashan Sooriyahetti thanks to you... now I can use Stackblitz and by rewriting my method and testing it out of the whole system I created... I've been able to find my mistake.

So actually sorry for that guys and thank you very much for your help and reactivity. Have nice coding time;)