Sample Component has data which array of object and it has child component on their array loop. Sample.component
export class SampleComponent implements OnInit {
data = [{ value: 3 }, { value: 1 }];
constructor() {}
ngOnInit(): void {}
valueChange() {
this.data[1].value = 5;
this.data = [...this.data];
}
whenComponentRerendered() {
console.log('Parent component rerendered');
}
consoleOutput() {
console.log('Console from button click');
}
}
<button (click)="valueChange()">
Change input to 5
</button>
<ng-container *ngFor="let item of data">
<app-samplechild [data]="item"></app-samplechild>
</ng-container>
now I need to detect changes when any value on object is changed from parent
export class SamplechildComponent implements OnInit {
@Input('data') data!: any;
constructor() {}
ngOnInit(): void {}
whenComponentRerendered() {
console.log('child component rerendered');
}
changeValue() {
this.data.value = 5;
}
}
<p>
The value from parent is
{{ data | json }}
</p>
I couldn't get the changes since the data is not an Input value. How to get changes in child? StackBlitz Note: This is only sample code, in realistic data has huge number arrays of object with multiple hierarchy.
Remove
changeDetection: ChangeDetectionStrategy.OnPush
fromSamplechildComponent
. Then it works fine. You should use default angularchangeDetection
system.