How to collect attributes from child components in template in parent component

Hi everybody!
Sorry for my bad English!
I got a problem.
I have a parent component for page:

import { Component, ElementRef, OnInit } from '@angular/core';
import { BannersSlideShow } from "../blocks/banners/slideshow";
import { CatalogCategory } from "../blocks/catalog/category";
import { CatalogTopProducts } from "../blocks/catalog/topproducts";


@Component({
  templateUrl : 'build/templates/default/pages/main.html',
  directives: [
                BannersSlideShow,
                CatalogCategory,
                CatalogTopProducts
              ]

})

export class MainPage implements OnInit{
  myElement: any;

  constructor(
    myElement: ElementRef
  )
  {
    this.myElement = myElement;

  }

 
  ngOnInit()
  {
    //console.log(this.myElement.nativeElement.getElementsByClassName('contentBlock'));
  }
}

with template:

<ion-content>
  <blocks-banners-slideshow class="contentBlock" [zone]="'main'" [slideOptions]="{loop:true}"></blocks-banners-slideshow>
  <blocks-catalog-category class="contentBlock" [root]="0"></blocks-catalog-category>
  <blocks-catalog-topproducts class="contentBlock" [dirs]="[0]" ></blocks-catalog-topproducts>
</ion-content>

blocks-banners-slideshow, blocks-catalog-category, blocks-catalog-topproducts it is child components.

I want in my parent page component class collect the attributes of child component’s. What is the best way to do this?