注：在鏈接的答案的代碼，只改變在車和結算所顯示的總金額，但不會改變它真的。
此答案也正在更改顯示的結帳總金額。我們需要在訂單創建過程中掛鉤的另一個功能來更新總金額。
對於Wordpress Ajax，您需要將腳本註冊到外部JS文件中，該文件將在js子文件夾內的活動主題文件夾中上傳。假設這個外部文件名將是pay_half.js。
1）這裏是會做登記，並將使WordPress的Ajax功能的功能：
add_action('wp_enqueue_scripts', 'ajax_change_shipping');
function ajax_change_shipping() {
// Only on front-end and checkout page
if(is_admin() || ! is_checkout()) return;
// Get the Path to the active theme or child theme or plugin folder
# $path = plugin_dir_url(__FILE__); // A plugin
# $path = get_template_directory_uri(); // A Normal theme
$path = get_stylesheet_directory_uri(); // A child theme
// Define the subfolder name
$subfolder = 'js';
// Define the file name
$filename = 'pay_half.js';
// Reference name of the script (should be unique)
$handle = 'pay-half';
// Set the ajaxurl parameter used in your script
$data = array(
'ajaxurl' => admin_url('admin-ajax.php'),
);
// The variable name whichwill contain the data
$name = 'pay_half';
// Registering the javascript file and enqueues it.
wp_enqueue_script($handle, $path."/$subfolder/$filename", array('jquery'), '1.0', true);
// Localizing the registered script (Here using Ajax)
wp_localize_script($handle, $name, $data);
}
代碼放在您的活動子主題（或主題的function.php文件），或者也可以任意插件文件。
2）現在的Javascript/jQuery的外部文件（命名爲：pay_half.js）：
jQuery(document).ready(function ($) {
var selectHalf = '#cash-on-delivery-wrap input[type="radio"]',
paymentMethod = 'input[name^="payment_method"]',
codWrap = $('.cash-on-delivery-wrap'),
cartGTotal = $('input#cart_gtotal').val(),
codPartial;
// Detecting payment method on load to show/hide cod custom options
if($(paymentMethod+':checked').val() == 'cod')
codWrap.show("fast");
else
codWrap.hide("fast");
// Live detecting choosen payment method to show/hide cod custom options
$('form.checkout').on('change', 'input[name^="payment_method"]', function() {
if ($(paymentMethod+':checked').val() == 'cod') {
codWrap.show("fast");
} else {
codWrap.hide("fast");
$('#cash-on-delivery-wrap input#cod-options_no').prop('checked', true);
}
$(document.body).trigger("update_checkout");
// console.log($(paymentMethod+':checked').val());
});
// The "Cod" custom options (ajax)
$(selectHalf).click(function(){
if($(selectHalf+':checked').val() == 'yes') codPartial = 'yes';
else codPartial = 'no';
$.ajax({ // This does the ajax request
url: pay_half.ajaxurl,
type : 'post',
data: {
'action':'cod_partial_payment', // Name of the php function
'cod_partial' : codPartial // Passing this variable to the PHP function
},
success:function(data) {
// Displaying the price (Ajax)
$('table.shop_table > tfoot > tr.order-total > td > strong > span').html(data.price_html);
if(codPartial == 'yes')
$('input#cart_remaining').val(data.price_remaining);
else
$('input#cart_remaining').val(0);
$(document.body).trigger("wc_fragment_refresh");
console.log(data);
},
error: function(error){
console.log(error);
}
});
});
});
3）您的自定義字段的顯示（revisisted）。
我已經添加了2個隱藏字段的總金額和剩餘金額。
add_action('woocommerce_review_order_before_payment', 'cod_payment_options', 10);
function cod_payment_options(){
echo '<style>.cod-button-options label{display:inline-block; margin:0 6px;}</style>
<div id="cash-on-delivery-wrap" class="cash-on-delivery-wrap">
<h3>' . __('Cash on delivery option') . '</h3>';
woocommerce_form_field('cod-options', array(
'type' => 'radio',
'class' => array('form-row-wide', 'cod-button-options'),
'label' => __('<b>Pay half (50%): </b>'),
'required' => false,
'options' => array(
'no' => __('No'),
'yes' => __('Yes'),
)
), 'no');
// Some additional hidden fields
echo '<input type="hidden" id="cart_gtotal" name="cart_gtotal" value="'. WC()->cart->total .'">
<input type="hidden" id="cart_remaining" name="cart_remaining" value="0" />
</div>';
}
代碼放在您的活動子主題（或主題）的function.php文件或也以任何插件文件。
4）驅動的PHP函數（WordPress的阿賈克斯）：
add_action('wp_ajax_nopriv_cod_partial_payment', 'cod_partial_payment');
add_action('wp_ajax_cod_partial_payment', 'cod_partial_payment');
function cod_partial_payment() {
if(! isset($_POST['cod_partial'])) return;
$current_state = $_POST['cod_partial'];
$remaining = 0;
if($current_state == 'yes'){
WC()->cart->total /= 2;
}
WC()->session->set('total', WC()->cart->total);
$response = array(
'price_html' => wc_price(WC()->cart->total),
'price_remaining' => WC()->cart->total,
);
header('Content-Type: application/json');
echo json_encode($response);
die(); // Always (to avoid an error 500)
}
代碼放在您的活動子主題（或主題的function.php文件），或者也可以任何插件文件。
5）其他PHP函數（更新訂單金額，將元數據保存，顯示消息）：
// Replacing the total amount when COD option is enabled
add_action('woocommerce_checkout_create_order', 'cod_options_change_order_total_ammount', 10, 2);
function cod_options_change_order_total_ammount($order, $data) {
if (! empty($_POST['cod-options']) && $_POST['cod-options'] == 'yes') {
$remaining = sanitize_text_field($_POST['cart_remaining']);
$total = WC()->cart->total - floatval($remaining);
WC()->session->set('total', $total);
$order->set_total($total);
}
}
// Updating order meta data for Cod selected option
add_action('woocommerce_checkout_update_order_meta', 'cod_options_update_order_meta', 10, 1);
function cod_options_update_order_meta($order_id) {
if (! empty($_POST['cod-options']) && $_POST['cod-options'] == 'yes') {
update_post_meta($order_id, '_cod_remaining_amount', sanitize_text_field($_POST['cart_remaining']));
update_post_meta($order_id, '_cod_partial_paid_amount', sanitize_text_field($_POST['cart_gtotal'] - $_POST['cart_remaining']));
}
update_post_meta($order_id, '_cod_partial_payment_option', sanitize_text_field($_POST['cod-options']));
}
// Displaying the remaining amount to pay in a custom message on Order received page (thank you)
add_action('woocommerce_thankyou_cod', 'cod_options_woocommerce_thankyou', 10, 1);
function cod_options_woocommerce_thankyou($order_id) {
if(get_post_meta($order_id, '_cod_partial_payment_option', true) == 'yes'){
$ra = '<span style="color:#96588a;">'.wc_price(get_post_meta($order_id, '_cod_remaining_amount', true)).'</span>';
?>
<ul class="woocommerce-order-overview woocommerce-thankyou-cod-options order_details">
<li class="woocommerce-order-overview__remaining_total order">
<strong><?php echo __("There is a remaining amount of $ra to pay on this order."); ?></strong>
</li>
</ul>
<?php
}
}
代碼放在您的活動子主題的function.php文件（或主題）或者在任何插件文件中。
此代碼在Woocommerce 3+上測試並正常工作。