private function validateExpression()
{
if (!empty($this->cron_expression)) {
$cronTab = new CronExpression($this->cron_expression, new \Cron\FieldFactory());
$order = array(5, 3, 2, 4, 1, 0);
foreach (array_reverse($order) as $position) {
$this->cron_parts[$position] = $cronTab->getExpression($position);
if (null === $this->cron_parts[$position] && $position <= 3) {
return FALSE;
}
}
return TRUE;
}
return FALSE;
}
