title: Angular Validator Pattern works in HTML but not in TypeScript
body: <p>Following Regular Expression does work in HTML like following example:</p>
  
  <pre><code>&lt;input type="text" formControlName="mgmtIP" class="input-text" pattern="([01]?\d\d?|2[0-4]\d|25[0-5])\.([01]?\d\d?|2[0-4]\d|25[0-5])\.([01]?\d\d?|2[0-4]\d|25[0-5])\.([01]?\d\d?|2[0-4]\d|25[0-5])"&gt;
  </code></pre>
  
  <p>But if I want to put that pattern in the FormGroup, the Validator isn't recognized:</p>
  
  <pre><code>mgmtIP: [host.mgmtIP, [
              Validators.required,
              Validators.pattern(/^([01]?\\d\\d?|2[0-4]\\d|25[0-5])\\.([01]?\\d\\d?|2[0-4]\\d|25[0-5])\\.([01]?\\d\\d?|2[0-4]\\d|25[0-5])\\.([01]?\\d\\d?|2[0-4]\\d|25[0-5])$/)
            ]],
  </code></pre>
  
  <p>I tried putting it in a string with taking away the <code>^</code> and the <code>$</code>. That didn't work neither</p>