title: Angular 4 enable HTML5 validation
body: <p>I want to use HTML5 validation in Angular 4 rather than their form's based validation/reactive validation.  I want to keep the validation running in the browser. </p>
  
  <p>It used to work in Angular 2, but since I've upgraded, I can't get even manually created forms without any angular directives to validate using HTML5.</p>
  
  <p>For instance, this won't validate in the browser at all:</p>
  
  <pre><code>&lt;form&gt;
  &lt;h2&gt;Phone Number Validation&lt;/h2&gt;
  &lt;label for="phonenum"&gt;Phone Number (format: xxxx-xxx-xxxx):&lt;/label&gt;&lt;br /&gt;
  &lt;input id="phonenum" type="tel" pattern="^\d{4}-\d{3}-\d{4}$" required&gt;
  
  &lt;input type="submit" value="Submit"&gt;
  
  &lt;/form&gt;
  </code></pre>