title: Passing Data onChange from parent to childs
body: <p>I hava a question about data binding. In my project i have parent and two childs
  Parent:</p>
  
  <pre><code>    directives: [firstChild,secondChild],
      template:'
   &lt;first-child [showList]="showList" (emitShowList)="getShowList($event)"&gt;&lt;/history-months-avg-header&gt;
   &lt;second-child [showList]="showList" (emitShowList)="getShowList($event)"&gt;&lt;/history-months-avg-header&gt;
      '
      export class FlexProductListComponent {
        private showList:any[]=[];
  
        getShowList(show:any[]){
              this.showList = show;
              console.log('nowa list',this.showList);
          }
  
      }
  </code></pre>
  
  <p>And the first child :</p>
  
  <pre><code>directives: [],
          template:'
  &lt;button  (click)="showHistoryDetails();" &gt;&lt;i class="fa fa-angle-double-right" aria-hidden="true"  &gt;&lt;/i&gt;&lt;/button&gt;
  
  export class firstChild{
      @Output() emitShowList = new EventEmitter&lt;any[]&gt;();
      @Input() showList: any[];
      public showHistoryStatus: boolean = false;
  
       showHistoryDetails() {
  
              if (this.showHistoryStatus) {
                  this.showHistoryStatus = false;
                  this.showList =             this.removeFromShowList(this.showList,this.HistoryComponent);
                  console.log('zmieniam na nie',this.showList);
                  this.emitShowList.emit(this.showList);
              } else {               
                  this.showHistoryStatus = true;
                  this.showList.push(this.HistoryComponent);
                  this.emitShowList.emit(this.showList);
  
              }
          }
  
      '
  </code></pre>
  
  <p>and the second child:</p>
  
  <pre><code>/*component ect*/
  
  directives:[],
  template: ``
  export class secondChild{
  @Input()   allHistoryChannels:any;
  @Input() set showList(var:any[]){
  console.log(var);
  /*another actions*/
  };
  </code></pre>
  
  <p>And right now problem. I want to, when i click on button in first child to add or remove item from array and edited array(showList) emit to parent.
  Parent get data and overvrite current  data in property showList. The new value in showList property should be passed to all binded childs.
  But it's dont work correctly. The second child logs only on start when show list are empty. I always think when we overvrite parent property and this property is binding with childs, the new value after save is sended to all binded childs.
  Looks like im wrong. So how its workin? Somebody can help me find the answer how to solve this problem? Thanks :)</p>