如何最好地在 Angular2 中使用 takeUntil 取消订阅 observable

Question

Hows best to unsubscribe from an observable using a takeUntil.

From what I understand takeUntil automatically does the complete for you.

Below is how I normally do a unsubscribe from an observable. But not sure if done correctly. Do I really need the "this.destroyed$.complete();" if takeUntil does the complete for me?

This is my current attempt that works but unsure if best method:

 private destroyed$: Subject<void> = new Subject();

 ngOnIt(): void {
    this.serviceA.getData
      .takeUntil(this.$destroyed)
      .subscribe(val => {
        console.log('Current value:', val);
      });
  };

  ngOnDestroy(): void {
    this.destroyed$.next();
    this.destroyed$.complete();
  };

I was thinking of removing the .complete in the ngOnDestory but not sure if that would cause memory leaks?

Answer 1

Personally I prefer this solution, have another subject just to handle unsubscribe and mix up with takeUntil probably make things too complex

 private _subscriptions:Subscription[];

 ngOnIt(): void {
  this._subscriptions.push(this.serviceA.getData
  .subscribe(val => {
    console.log('Current value:', val);
  })
   )
};

ngOnDestroy(): void {
this._subscriptions.foreach(subs=>{ subs.unsubscribe()})
};