title: Is there a way to programmatically determine if an input date field is incomplete?
body: <p>I'm stuck with the following question: how can I determine if an input date field is incompletely submitted? For example, if I send <code>12/09/aaaa</code> as a value, the value actually sent is <code>null</code>, which is the same value I obtain if I send <code>gg/mm/aaaa</code>, i.e. the empty value. Is there a way to discriminate via JS between the two cases? (Actually, I'm using Vue.js but I think it's not so important.)</p>
  <p>Thanks in advance!</p>