title: How to do masking using angular 5
body: <p>Is it possible to create a mask in Angular 5 that looks like this:</p>
  
  <p><code>XXX-XX-1234</code></p>
  
  <p>And when the user clicks on the text box it should change to the following text:</p>
  
  <p><code>1234121234</code></p>
  
  <p>Thanks a ton!</p>