onValueChanged method
      
void
onValueChanged({})
      
     
    
view is a String that will be displayed
to a user. This must be null for text inputs
since they are updated on user input but for
other inputs e.g. a LiteDatePicker this must be a
formatted date representation
Implementation
void onValueChanged({
  required String formName,
  required String fieldName,
  required Object? value,
  required String? view,
  bool isInitialValue = false,
}) {
  _FormGroupWrapper? group = _formGroups[formName];
  if (group != null) {
    group.tryFindField(fieldName)?.onChange(
          value,
          isInitialValue,
          view,
        );
    liteFormRebuildController.rebuild();
  }
}