Use a setter for the ViewChild: private contentPlaceholder: ElementRef; @ViewChild(‘contentPlaceholder’) set content(content: ElementRef) { if(content) { // initially setter gets called with undefined this.contentPlaceholder = content; } } The setter is called with an element reference once *ngIf becomes true. Note, for Angular 8 you have to make sure to set { static: false }, … Read more
Try one of these: ApplicationRef.tick() – similar to AngularJS’s $rootScope.$digest() — i.e., check the full component tree NgZone.run(callback) – similar to $rootScope.$apply(callback) — i.e., evaluate the callback function inside the Angular zone. I think, but I’m not sure, that this ends up checking the full component tree after executing the callback function. ChangeDetectorRef.detectChanges() – similar … Read more
I had a similar issue. Looking at the lifecycle hooks documentation, I changed ngAfterViewInit to ngAfterContentInit and it worked.
Actually, there are two ways of detecting and acting upon when an input changes in the child component in angular2+ : You can use the ngOnChanges() lifecycle method as also mentioned in older answers: @Input() categoryId: string; ngOnChanges(changes: SimpleChanges) { this.doSomething(changes.categoryId.currentValue); // You can also use categoryId.previousValue and // categoryId.firstChange for comparing old and new … Read more