title: Conditional ng-pattern in angular js
body: <p>Is there a way to achieve conditional ng-pattern in angularjs</p>
  
  <pre><code>ng-pattern="(myForm.exipration.$dirty ? ('/^\d{2}[/]\d{4}$/') : '')"
  </code></pre>
  
  <p>i tried like above, but does not help.</p>