Günay's Coding World

OnDestroy() Unsubscribe from Observables and DOM events. Stop interval timers. Unregister all callbacks that this directive registered with global or application services. You risk memory leaks if you neglect to do so. EventEmitter Here are the pertinent excerpts from that  HeroDetailComponent : src/app/hero-detail.component.ts (template) template : ` <div> <img src="{{heroImageUrl}}"> <span [style.text-decoration]="lineThrough"> {{prefix}} {{hero?.name}} </span> <button (click)="delete()"> Delete </button> </div>` src/app/hero-detail.component.ts (deleteRequest) // This component makes a request but it can't actually delete a hero. deleteRequest = new EventEmitter < Hero >(); delete () { this . deleteRequest . emit ( this . hero ); } The component defines a  deleteRequest  property that returns an  EventEmitter . When the user clicks  delete , the component invokes t...

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