Event each time component becomes visible

Question

Is there a way in Angular2 to have an event fired when my component becomes visible? It is placed in a tabcontrol and I want to be notified when the user switches. I'd like my component to fire an event.

Answer 1

What I finally did (which is not very beautiful but works while I don't have a better way to do it...) is to use the ngAfterContentChecked() callback and handle the change myself.

@ViewChild('map') m; private isVisible: boolean = false; ngAfterContentChecked(): void {     if (this.isVisible == false && this.m.nativeElement.offsetParent != null)     {         console.log('isVisible switched from false to true');         this.isVisible = true;         this.Refresh();     }     else if (this.isVisible == true && this.m.nativeElement.offsetParent == null)     {         console.log('isVisible switched from true to false');         this.isVisible = false;     } }