custom plugin works

Hi!

There is an extension on the website, which is supposed to make the VAT value zero after entering the tax number in the case of a company purchase. However, it happens sometimes that the VAT is left in, this is not related to whether the user is registered or not and I have not managed to reproduce the error yet, but unfortunately I have received orders… The coding of the extension is as follows:

<?php
/*
Plugin Name: Zero ado
Plugin URI: http://yourwebsite.com/
Description: Validates VAT numbers during checkout and applies a zero tax rate if the VAT number is valid.
Version: 1.0
Author: Your Name
Author URI: http://yourwebsite.com/
*/

// Enqueueing the javascript file
function zero_ado_scripts() {
    wp_enqueue_script('zero-ado-js', plugin_dir_url(__FILE__) . 'zero-ado.js', array('jquery'), '1.0', true);
    wp_localize_script('zero-ado-js', 'ajax_object', array('ajax_url' => admin_url('admin-ajax.php')));
}
add_action('wp_enqueue_scripts', 'zero_ado_scripts');

// VAT number validation function
function validate_vat_number($vat) {
    return preg_match('/^\d{8}-\d{1}-\d{2}$/', $vat);
}

// AJAX handler to validate VAT and apply zero rate
function check_vat_number_ajax_handler() {
    if (validate_vat_number($_POST['billing_tax_number'])) {
        WC()->customer->set_is_vat_exempt(true);
        echo json_encode(['success' => true]);
    } else {
        WC()->customer->set_is_vat_exempt(false);
        echo json_encode(['success' => false, 'error' => 'Nem megfelelő adószám formátum!']);
    }
    
    WC()->cart->calculate_totals();
    wp_die();
}
add_action('wp_ajax_check_vat_number', 'check_vat_number_ajax_handler');
add_action('wp_ajax_nopriv_check_vat_number', 'check_vat_number_ajax_handler');
?>

jQuery(function($) {
    var vatValidated = true; // Default to true

    function setLoader(loading) {
        // ... (maradhat változatlan)
    }

    function validateVATNumber() {
        var vatNumber = $('#billing_tax_number').val();
        var companyName = $('#billing_company').val(); // Get the company name

        // Check if the company name is empty
        if (companyName.trim() === '') {
            vatValidated = true; // No VAT validation required if the company name is empty
            $('button[name="woocommerce_checkout_place_order"]').prop('disabled', false); // Enable place order button
            return;
        }

        setLoader(true); // Show loading

        $.ajax({
            url: ajax_object.ajax_url,
            method: 'POST',
            dataType: 'json', // Expect JSON response from the server
            data: {
                action: 'check_vat_number',
                billing_tax_number: vatNumber
            },
            success: function(response) {
                if(response.success) {
                    vatValidated = true; // VAT is valid
                } else {
                    vatValidated = false; // VAT is invalid
                    alert('Nem megfelelő adószám formátum!');
                }
            },
            error: function() {
                vatValidated = false; // In case of AJAX error, consider VAT as invalid
            },
            complete: function() {
                setLoader(false); // Hide loading
                $('body').trigger('update_checkout');
                // Re-check if the place order button should be enabled
                $('button[name="woocommerce_checkout_place_order"]').prop('disabled', !vatValidated);
            }
        });
    }

    // Run VAT validation when the VAT number field is changed
    $('#billing_tax_number').on('change', function() {
        validateVATNumber();
    });

    // Check VAT validation status before placing the order
    $('form.checkout').on('checkout_place_order', function() {
        if (!vatValidated) {
            validateVATNumber(); // Re-validate VAT if not done
            return false; // Prevent the form from submitting
        }
        return true; // VAT is validated or not required, proceed with form submission
    });

    // Initially disable the place order button until VAT is validated
    $('button[name="woocommerce_checkout_place_order"]').prop('disabled', true);

    // Clear the VAT number field on page load
    $('#billing_tax_number').val('');
});

Thank You!

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