What it does

Lifecycle hook that is called when any data-bound property of a directive changes.

How to use


@Component({selector: 'my-cmp', template: `...`}) class MyComponent implements OnChanges { @Input() prop: number; ngOnChanges(changes: SimpleChanges) { // changes.prop contains the old and the new value... } }

Class Overview

class OnChanges {
ngOnChanges(changes: SimpleChanges) : void


Class Description

Class Details

exported from @angular/core/index, defined in @angular/core/src/metadata/lifecycle_hooks.ts