Angular/RxJs When should I unsubscribe from `Subscription`

Question

When should I store the Subscription instances and invoke unsubscribe() during the NgOnDestroy life cycle and when can I simply ignore them?

Answer 1

I like the last two answers, but I experienced an issue if the the subclass referenced "this" in ngOnDestroy.

I modified it to be this, and it looks like it resolved that issue.

export abstract class BaseComponent implements OnDestroy {
    protected componentDestroyed$: Subject;
    constructor() {
        this.componentDestroyed$ = new Subject();
        let f = this.ngOnDestroy;
        this.ngOnDestroy = function()  {
            // without this I was getting an error if the subclass had
            // this.blah() in ngOnDestroy
            f.bind(this)();
            this.componentDestroyed$.next(true);
            this.componentDestroyed$.complete();
        };
    }
    /// placeholder of ngOnDestroy. no need to do super() call of extended class.
    ngOnDestroy() {}
}