title: How to display message on pattern validation?
body: <p>I added pattern attribute to template </p>
  
  <pre><code>&lt;input class="form-control" type="text" id="elementName"
                                     [(ngModel)]="elementName" name="elementName"
                                     (input)="onElementNameChanged()" #name="ngModel" required pattern="[A-Za-z0-9_)*\S]*" &gt;
  </code></pre>
  
  <p>How to add message to display if input is not correct?</p>
  
  <p>Something like wont work:</p>
  
  <pre><code>&lt;div [hidden]="!name.errors.pattern"
       class="alert alert-danger"&gt;
       Name must match pattern
  &lt;/div&gt;
  </code></pre>