Обязательное поле количество в опциях

[DM8985]

Подскажите, правильно ли я сделал проверку на обязательное заполнение поля количество в опциях:

controller

if (isset($this->error['option_quantity'])) {
	$data['error_option_quantity'] = $this->error['option_quantity'];
} else {
	$data['error_option_quantity'] = array();
}
if (isset($this->request->post['product_option'])) {
	foreach ($this->request->post['product_option'] as $product_option_id => $product_option) {
		foreach ($product_option['product_option_value'] as $product_option_value) {
			if ((utf8_strlen($product_option_value['quantity']) < 1) || (utf8_strlen($product_option_value['quantity']) > 8)) {
				$this->error['option_quantity'][$product_option_id] = $this->language->get('error_option_quantity');
			}
		}
	}
}

tpl

<input type="number" min="0" name="product_option[<?php echo $option_row; ?>][product_option_value][<?php echo $option_value_row; ?>][quantity]" value="<?php echo $product_option_value['quantity']; ?>" placeholder="<?php echo $entry_quantity; ?>" class="form-control">
<?php if (isset($error_option_quantity[$option_row])) { ?><small class="invalid-feedback"><?php echo $error_option_quantity[$option_row]; ?></small><?php } ?>