title: Angular 2 Reactive Forms checkbox state
body: <p>How can I handle this situation? Displaying 3 checkboxes, every one can add/remove an <code>indicador</code> to the logic, how can I know if is checked? shall i create 2 methods (<code>addIndicador</code> &amp; <code>removeIndicador</code>)?</p>
  
  <p><strong>Extra</strong>: How can i display/hide a div when the checkbox are or not checked?</p>
  
  <pre><code>&lt;li *ngFor="let indicador of indicadores"&gt;
    &lt;input type="checkbox" id="{{ indicador.id }}" (change) = "addIndicador(indicador.id)" /&gt;
     &lt;label for="{{ indicador.id }}"&gt;{{ indicador.nombre }}&lt;/label&gt;
  &lt;/li&gt;
  
  
  
  addIndicador(indicador: number):void {
      let answers: FormArray = new FormArray([]); 
      let id = indicador;
  
      (&lt;FormArray&gt;this.customForm.controls['indicadores']).push(
          new FormGroup({
              id: new FormControl(id),
              answers: answers
          })
      )
  }
  </code></pre>