IONIC 2: afterViewInit and afterContentInit (access a child component)

Testing Ionic 2 now, and stumbled across this need:

From a Page, how to access the child components in an optimal way?
There is the app.getComponent('id') - but it is not working within the constructor of a Page, as the child components are not ready and registered yet.

Seems the Ionic 2 Page can use the new afterViewInit and thus this becomes possible:

class ParentComponent
    constructor( app: IonicApp ) { = app;
        // This returns 'undefined':
        // this.childComponent ='childId');
    afterViewInit() {
        // This works:
        this.childComponent ='childId');

But: is there an easy way to fetch the child component from the parent component, without going all the way up to the app?
@ContentChildren and QueryList are an option, but unnecessarily complex.