title: Angular - DialogRef - Unsubscribe - Do I need to unsubscribe from afterClosed?
body: <p>I got asked by one of my colleagues if we need to unsubscribe from the afterClosed() Observable of a Dialog.</p>
  
  <p>We are using the takeUntil pattern to unsubscribe from all Observables on ngOnDestroy().</p>
  
  <pre><code>this.backEvent = fromEvent(window, 'popstate')
      .pipe(
          takeUntil(this.destroy$)
      )
      .subscribe(
          () =&gt; {
              this.navigationService.backClicked = true;
              this.navigationService.navigateBackToDirectoryCenter();
          }
      );
  </code></pre>
  
  <p>ngOnDestroy()</p>
  
  <pre><code>ngOnDestroy() {
      this.destroy$.next();
      this.destroy$.complete();
  }
  </code></pre>
  
  <p>So is it necessary to unsubscribe from afterClosed() Observable?</p>
  
  <pre><code>dialogRef.afterClosed().subscribe(
      (data) =&gt; {
              console.log(data);
          }
      },
  );
  </code></pre>
  
  <p>or?</p>
  
  <pre><code>dialogRef.afterClosed()
      .pipe(
          takeUntil(this.destroy$)
      )
      .subscribe(
          (data) =&gt; {
              console.log(data);
          },
      );
  </code></pre>