How can I trigger an event/function to many child from parent component?


I am having a parent that needs to “trigger” or pass a data that will trigger a function. Let’s say “reddish()”.
I “ngfor” the child.

<div  *ngFor="let item of object">
<child [item]="item"> </child>

I need on certain event coming from Parent, that all child with a certain condition (if they were touched) get reddish. Reddish is for the example.
in a nutshell: if parent say get reddish and they are touched => they get reddish.

I checked angular2 doc, and the only solution I am finding is with “input” and add another attribute

<child [item]="item.item"  [reddish]="item.bool"> </child>

And then a ngonchange? Doing that way it is like my child-component’s method is useless, isn’t it?

A bit lost in Angular :slight_smile:
Thanks for your help,