public function afterValidate()
{
if ($this->worklist->scheduled) {
if (empty($this->when)) {
$this->addError('when', $this->getAttributeLabel('when') . ' is required when the Worklist is scheduled.');
}
} else {
if (!empty($this->when)) {
$this->addError('when', $this->getAttributeLabel('when') . ' cannot be set when the Worklist not scheduled.');
}
}
parent::afterValidate();
}