protected function submitEditProductClass()
    {
        if ($this->isPosted('delete') && $this->canDeleteProductClass()) {
            $this->deleteProductClass();
        } else if ($this->isPosted('save') && $this->validateEditProductClass()) {
            if (isset($this->data_product_class['product_class_id'])) {
                $this->updateProductClass();
            } else {
                $this->addProductClass();
            }
        }
    }