title: Angular Reactive forms : how to reset form state and keep values after submit
body: <p>In an Angular reactive form. How to reset only the <strong>state</strong> of form after successful submit?</p>
  
  <p>Here is the process:</p>
  
  <ul>
  <li>Create the form and <code>setValue</code> from service result</li>
  <li>Modify values and submit the form</li>
  <li>If form is properly submitted to service, then reset and keep values</li>
  </ul>
  
  <p><strong>How to keep values as modified and reset the form to its pristine state.</strong></p>
  
  <p>A form.reset() simply empty the form. But if I don't call it, the state is not reset and for example my validations depending on form state classes (pristine, dirty, valid etc.) are still there. </p>