How to observe touched event on Angular 2 NgForm? : <p>It is possible to subscribe a callback to an <code>NgForm</code>'s <code>valueChanges</code> observable property in order to react to changes in the values of the controls of the form.</p>

<p>I need, in the same fashion, to react to the event of the user <em>touching one of the form controls</em>.</p>

<p><a href="https://github.com/angular/angular/blob/master/modules/%40angular/forms/src/directives/abstract_control_directive.ts" rel="noreferrer">This class</a> seem to define the <code>valueChanges</code> Observable and the <code>touched</code> property is defined as a boolean.</p>

<p><strong>Is there a way to to react to the "control touched" event?</strong> </p>
