فیلد تشخیص صحت کد ملی در ووکامرس

				
					// The function of checking the accuracy of the national code
function check_national_code($code) {
    if (!preg_match('/^[0-9]{10}$/', $code))
        return false;
    for ($i = 0; $i < 10; $i++)
        if (preg_match('/^' . $i . '{10}$/', $code))
            return false;
    for ($i = 0, $sum = 0; $i < 9; $i++)
        $sum += ((10 - $i) * intval(substr($code, $i, 1)));
    $ret = $sum % 11;
    $parity = intval(substr($code, 9, 1));
    if (($ret < 2 && $ret == $parity) || ($ret >= 2 && $ret == 11 - $parity))
        return true;

    return false;
}

// Adding national code field to WooCommerce Checkout page
function add_custom_national_code_field($checkout_fields) {
    $checkout_fields['billing']['billing_national_code'] = array(
        'type' => 'text',
        'label' => __('کد ملی', 'your-theme-domain'),
        'required' => true,
        'class' => array('form-row-wide'),
        'priority' => 1, // Set the priority value to 1 to make it the first field
    );

    return $checkout_fields;
}
add_filter('woocommerce_checkout_fields', 'add_custom_national_code_field', 10, 1);

// Validate national code field
function validate_custom_national_code_field() {
    $code = isset($_POST['billing_national_code']) ? sanitize_text_field($_POST['billing_national_code']) : '';

    if (!empty($code) && !check_national_code($code)) {
        wc_add_notice(__('کد ملی وارد شده معتبر نمی باشد!'), 'error');
    }
}
add_action('woocommerce_checkout_process', 'validate_custom_national_code_field');

// Saved national code in the order
function save_custom_national_code_field($order_id) {
    if (!empty($_POST['billing_national_code'])) {
        update_post_meta($order_id, 'billing_national_code', sanitize_text_field($_POST['billing_national_code']));
    }
}
add_action('woocommerce_checkout_update_order_meta', 'save_custom_national_code_field');

// Display the national code in the orders section of the admin
function checkout_field_display_admin_order_meta($order) {
    echo '<p><strong>' . __('کد ملی') . ':</strong> ' . get_post_meta($order->id, 'billing_national_code', true) . '</p>';
}
add_action('woocommerce_admin_order_data_after_billing_address', 'checkout_field_display_admin_order_meta', 10, 1);