Child component:
export class Child {
@Input() public value: string;
public childFunction(){...}
}
Parent component:
export class Parent {
public value2: string;
function1(){ value2 = "a" }
function2(){ value2 = "b" }
}
Parent view:
<child [value]="value2">
Is there any way to call childFunction() every time the value2 is changed in this structure?
You can use the ngOnChanges() lifecycle hook
export class Child {
@Input() public value: string;
ngOnChanges(changes) {
this.childFunction()
}
public childFunction(){...}
}
or use a setter
export class Child {
@Input()
public set value(val: string) {
this._value = val;
this.childFunction();
}
public childFunction(){...}
}
changes parameter contains an entry for each changed input. See the "lifecycle hook" link above for more details.
ngOnChanges() is only called after Angulars change detection detects a change and updates an @Input() binding.