angular parent get value from child code example

Example 1: send event to child component angular

Parent-Component

eventsSubject: Subject<void> = new Subject<void>();

emitEventToChild() {
  this.eventsSubject.next();
}


Parent-HTML

<child [events]="eventsSubject.asObservable()"> </child>


Child-Component

private eventsSubscription: Subscription;

@Input() events: Observable<void>;

ngOnInit(){
  this.eventsSubscription = this.events.subscribe(() => doSomething());
}

ngOnDestroy() {
  this.eventsSubscription.unsubscribe();
}

Example 2: input property angular

//passing properties to child elements
<app-slider [title]="'This is a title'"> </app-slider>

//inside the component slider i add just before the constructor :
.
.
@input() title: string;
constructor(){
}


//after this we can use these new property inside the .html file of the component
<div id='slider' class='slider-big'>
  <h1> {{title}}</h1>

</div>