title: JavaFx - When does StringConverter.fromString execute in DatePicker
body: <p>I am trying to customize a DatePicker and would like to add a red border to the TextField/Editor of the DatePicker while the user input is invalid and remove it again as soon as it becomes valid. The only problem I have with this is triggering the validation, I can't seem to get the fromString method in the converter to execute (which then updates a property and so on ..., this is all fine).</p>
  
  <p>I was under the impression the fromString method would execute on user input, but apparently it does not, so my question basically comes down to "when does the fromString method execute".</p>