title: Angular reactive form two way binding
body: <p>I'm having trouble deciding what is the best way for Angular reactive-form two way data_binding.
  I want to have an ngmodel on my input, in the form in order to work with a directive that use the model. But in order to do that, I have to work with two objects like so:</p>
  
  <pre><code>&lt;form [formGroup]="form"&gt;
    &lt;input name="first" formControlName="first" [(ngModel)]="example.first"/&gt;
    &lt;input name="last" formControlName="last" [(ngModel)]="example.last"/&gt;
  &lt;/form&gt;
  
  export class App {
    form: FormGroup;
    example = { first: '', last: '' };
  
    constructor(builder: FormBuilder) {
      this.form = builder.group({
        first: '',
        last: ''
      })
    }
  }
  </code></pre>
  
  <ol>
  <li>the example</li>
  <li>the form it self</li>
  </ol>
  
  <p>and it complex my code.</p>
  
  <p>what is the best way?</p>