public function getEditable($is_create = true)
    {
        return
            (
                $this->getParent()->getEditable() ||
                $this->getParent()->getRequired()
            ) &&
            ! $this->getField()->getCalculated() &&
            ! $this->getField()->getAutoNumber() &&
            (
                $is_create && $this->getField()->getCreateable() ||
                ! $is_create && $this->getField()->getUpdateable()
            )
        ;
    }