title: How do I indicate a DevExtreme dx-date-box is required?
body: <p>So far I've found this related answer: <a href="https://stackoverflow.com/questions/43503999/angular-2-dev-extreme-dx-date-box-validation-of-required-field">Angular 2 dev extreme dx-date-box validation of required field</a></p>
  
  <p>And this supposedly helpful AngularJS example: <a href="https://js.devexpress.com/Demos/WidgetsGallery/Demo/Validation/Overview/AngularJS/Light/" rel="nofollow noreferrer">https://js.devexpress.com/Demos/WidgetsGallery/Demo/Validation/Overview/AngularJS/Light/</a></p>
  
  <p>...but none of this is working for me in an Angular 6 project. There doesn't seem to be a <code>dx-validator</code> (or <code>dxValidator</code>) property that I can set. I've used:</p>
  
  <pre><code>@ViewChild(DxDateBoxComponent) dateBox: DxDateBoxComponent;
  </code></pre>
  
  <p>...to get a reference to the date box component, but I haven't found any methods on the object I can use, or fields I can set, to get the job done. Whatever <code>this.dataBox.validator</code> is, it requires a bunch of private fields that I wouldn't know how to define, so I don't think it has anything to do with the kind of validators I've seen in the examples I've looked at.</p>