在 class-wc-cart.php 裡可以看到：

public function __construct() {
	$this->session          = new WC_Cart_Session( $this );
	$this->fees_api         = new WC_Cart_Fees( $this );
	$this->tax_display_cart = get_option( 'woocommerce_tax_display_cart' );

	// Register hooks for the objects.
	$this->session->init();

	add_action( 'woocommerce_add_to_cart', array( $this, 'calculate_totals' ), 20, 0 );
	add_action( 'woocommerce_applied_coupon', array( $this, 'calculate_totals' ), 20, 0 );
	add_action( 'woocommerce_cart_item_removed', array( $this, 'calculate_totals' ), 20, 0 );
	add_action( 'woocommerce_cart_item_restored', array( $this, 'calculate_totals' ), 20, 0 );
	add_action( 'woocommerce_check_cart_items', array( $this, 'check_cart_items' ), 1 );
	add_action( 'woocommerce_check_cart_items', array( $this, 'check_cart_coupons' ), 1 );
	add_action( 'woocommerce_after_checkout_validation', array( $this, 'check_customer_coupons' ), 1 );
}

由於 calculate_totals 執行多次，所以 woocommerce_before_calculate_totals 也會被執行多次，所以放在 $cart_object 裡的變數也會被寫入多次，解法是在woocommerce_before_calculate_totals 裡，請勿取出$cart_object 的 price, 而是再從 product object 裡去取出 price 即可。

I see exactly the same issue – my hooked function is firing twice, leading to the option price being added at 2x the cost. My solution was to load the product, get the price from that and then add my incremental cost to that.

function tbk_woo_update_option_price( $cart_object ) {

$option_price = 3.50;
foreach ( $cart_object->get_cart() as $cart_item_key => $cart_item ) {

        $item_id = $cart_item['data']->id;
        //Hook seems to be firing twice for some reason... Get the price from the original product data, not from the cart...
        $product = wc_get_product( $item_id );
        $original_price = $product->get_price();
        $new_price = $original_price + $option_price;
        $cart_item['data']->set_price( $new_price );
}

} add_action( ‘woocommerce_before_calculate_totals’, ‘tbk_woo_update_option_price’, 1000, 1 );

前言：

有些網站可能有多個運送方式，有些網站沒有，我相信幾乎大多數的小網站只會用到「一組」，不會用到第2組的運送方式，一組裡就已經有多個項目了，相信就很夠用，但WooCommerce 設計上又要弄的有彈性給更多的人使用，要解決這個問題，有多種解法。

我覺得最好的解法是 Nel Tseng 所提供的，增加下面這段hook 的function 到 functions.php：

// change 運送方式1 to 運送方式
// define the woocommerce_shipping_package_name callback 
function filter_woocommerce_shipping_package_name( $sprintf, $i, $package ) { 
 // make filter magic happen here... 
 return '運送方式';
}; 
add_filter( 'woocommerce_shipping_package_name', 'filter_woocommerce_shipping_package_name', 10, 3 );

WooCommerce 實際用到的程式碼：includes/wc-cart-functions.php

// @codingStandardsIgnoreStart
'package_name' => apply_filters( 'woocommerce_shipping_package_name', sprintf( _nx( 'Shipping', 'Shipping %d', ( $i + 1 ), 'shipping packages', 'woocommerce' ), ( $i + 1 ) ), $i, $package ),

我之前的解法是透過「Loco Translate」外掛來解決，去置換掉翻譯用的語言對應檔，但這個解法的問題在，官方更新了新的版本的語言對應檔之後，我們的設定值又會被蓋過去，變成每次更新完又要去重新修改一次，如果是修改 functions.php 就可以解決這個問題。

資料來源：

woocommerce_shipping_package_name
http://hookr.io/filters/woocommerce_shipping_package_name/

我的 WooCommerce 網站：
http://moca-shop.com/cart/

購物車截圖：

解法：

// define the woocommerce_valid_order_statuses_for_cancel callback 
function filter_woocommerce_valid_order_statuses_for_cancel( $array ) { 
 // make filter magic happen here... 
 return array('on-hold', 'pending', 'failed' ) );
}; 
 
// add the filter 
add_filter( 'woocommerce_valid_order_statuses_for_cancel', 'filter_woocommerce_valid_order_statuses_for_cancel', 10, 1 );

資料來源：

woocommerce_valid_order_statuses_for_cancel
The WordPress Core woocommerce valid order statuses for cancel hook.

http://hookr.io/filters/woocommerce_valid_order_statuses_for_cancel/#

Action and Filter Hook Reference

https://docs.woocommerce.com/wc-apidocs/hook-docs.html

當要嫁接一個 Action 的時候，外掛會使用如下的函式來加入

add_action ( 'hook_name', 'your_function_name', [priority, [accepted_args]] );

當要嫁接一個 Filter 的時候，外掛會使用如下的函式來加入

add_filter ( 'hook_name', 'your_function_name', [priority, [accepted_args]] );

你會發現兩者長相差不多，其各個參數的意義解釋如下
hook_name => 欲嫁接點的 action /filter hook 名稱
your_function_name => 所需要執行的函數名稱
priority => 優先權，預設值為 10，越小的數字越先執行
accepted_args => 你所執行的函數有幾個輸入值(參數)，預設為 1。某些 Action (Filter) 提供操過 2 個參數時即可以此設定。

那你會好奇在實際寫作的時候有多少得可以使用呢？
我也不清楚，這一直因為 WordPress 的版本更新而變更者，可以前往官方網站的 Codex 中有詳細說明。
Action 參考列表
Filter 參考列表

參考看看這個範例：

  public function get_variation_price( $min_or_max = 'min', $include_taxes = false ) {
    $prices = $this->get_variation_prices( $include_taxes );
    $price  = 'min' === $min_or_max ? current( $prices['price'] ) : end( $prices['price'] );
    return apply_filters( 'woocommerce_get_variation_price', $price, $this, $min_or_max, $include_taxes );
  }

相關文章：

Class WC_Product_Variable

https://docs.woocommerce.com/wc-apidocs/class-WC_Product_Variable.html

WooCommerce預設的 Rule 如下：

Product Permalinks

These settings control the permalinks used for products:

If you’re not using pretty permalinks, ‘default’ will be the only optional available to you and will use ID based URLs. e.g. yourdomain.com/?product=111. If you are using pretty permalinks, the default will be yourdomain.com/product/product-name.

The other options allow you to prepend the product permalinks with something custom, such as the shop page name, or a completely custom permalink you define.

Please note: The product custom base should not conflict with the taxonomy permalink bases. If you set the product base to ‘shop’ for example, you should not set the product category base to ‘shop’ too as this will not be unique and will conflict. WordPress requires something unique so it can distinguish categories from products.

The site that I am working on uses the following “pretty” permalink structure:

http://example.com/blog/my-special-post

But for a custom post type my client would like to avoid having a “pretty” slug:

http://example.com/product/142

How can the post ID be used in place of the slug for the custom post type?

I believe that this might be possible using WP_Rewrite, but I do not know where to begin.

This is what I use to rewrite custom post type URLs with the post ID. You need a rewrite rule to translate URL requests, as well as a filter on post_type_link to return the correct URLs for any calls to get_post_permalink():

add_filter('post_type_link', 'wpse33551_post_type_link', 1, 3);

function wpse33551_post_type_link( $link, $post = 0 ){
    if ( $post->post_type == 'product' ){
        return home_url( 'product/' . $post->ID );
    } else {
        return $link;
    }
}

add_action( 'init', 'wpse33551_rewrites_init' );

function wpse33551_rewrites_init(){
    add_rewrite_rule(
        'product/([0-9]+)?$',
        'index.php?post_type=product&p=$matches[1]',
        'top' );
}

I’m looking for a way to put a Woocommerce product ID in a URL, e.g.:

domain.com/product-category/id/product-title

The ID is the product’s post ID, e.g. “12092”. Automatically created by WooCommerce in WordPress.

Can this be done in a way? Either easily through the WordPress permalinks settings or in a different way through hacking my way into the files.

This nearly works:

<?php

add_filter('post_type_link', 'wpse33551_post_type_link', 1, 3);

function wpse33551_post_type_link( $link, $post = 0 ){
if ( $post->post_type == 'product' ){
    return home_url( 'p/' . $post->ID );
} else {
    return $link;
}
}

add_action( 'init', 'wpse33551_rewrites_init' );

function wpse33551_rewrites_init(){
add_rewrite_rule(
    'product/([0-9]+)?$',
    'index.php?post_type=product&p=$matches[1]',
    'top' );
}

?>

But the output is:

 domain.com/p/45

I’d like it to be:

 domain.com/p/45/title-of-the-post

Use a more permissive regular expression to accept any url that ends with /p/[id][anything]

<?php

add_filter('post_type_link', 'wpse33551_post_type_link', 1, 3);
function wpse33551_post_type_link( $link, $post = 0 ){
    if ( $post->post_type != 'product' )
      return $link;

    return home_url( 'p/' . $post->ID . '/' . $post->post_name );
}

add_action( 'init', 'wpse33551_rewrites_init' );
function wpse33551_rewrites_init(){
    add_rewrite_rule(
        'p/([0-9]+)?.*?$',
        'index.php?post_type=product&p=$matches[1]',
        'top'
    );
}

?>

You might need to ‘reset’ your permalinks in the settings menu for WordPress to accept the new rule.

有了這個功能，就可以不用自己「手動」去新增欄位名稱和欄位內容了。

執行畫面：

Source code:

function max_custom_tab_options_tab_buy_source() {
?>
 <li class="advanced_options advanced_tab" id="max_custom_tab_buy_source"><a href=""><?php _e('Buy Source', 'woocommerce'); ?></a></li>
<?php
}

function max_custom_tab_options_buy_source() {
?>
<script>
 jQuery(document).ready(function(){
 jQuery('#max_custom_tab_buy_source').click(function(){
 jQuery('#max_buy_source_html_content_div_main').show();
 });
 });
</script>

<?php 
 global $product;
 global $post;

 $val= get_post_meta($post->ID,'buy_source', true); 
?>
<div id="max_buy_source_html_content_div_main" class="panel woocommerce_options_panel hidden" style="display:none;" >
 <div class="options_group hide_if_external">
 <p class="form-field _purchase_note_field ">
 <label for="buy_source"><?php _e('Buy Source', 'woocommerce'); ?></label>
 <textarea class="short" style="" name="buy_source" id="buy_source" placeholder="" rows="4" cols="20"><?php echo isset($val)?$val:''; ?></textarea>
 </p> 
 </div>
</div>

<?php 
}

function max_process_product_meta_custom_tab_buy_source( $post_id ) 
{
 $buy= $_POST['buy_source'];
 update_post_meta( $post_id, 'buy_source', $buy );
}

add_action('woocommerce_process_product_meta', 'max_process_product_meta_custom_tab_buy_source');
add_action('woocommerce_product_write_panel_tabs', 'max_custom_tab_options_tab_buy_source'); 
add_action('woocommerce_product_write_panels', 'max_custom_tab_options_buy_source');

其他無大面積商品時：

設定方式，目前是「純手工」，在商品的編輯畫面裡增加metadata:

shipping_post_only = 1

純手工去加入欄位太不人性化，增加 3個副程式，就可以在 WooCommerce 裡增加新的Tab.
WordPress教學 – 增加自己的Tab在WooCommerce商品裡
https://stackoverflow.max-everyday.com/2017/04/wordpress-add-new-product-tab/

我的 functions.php

function dynamically_show_shipping_rates( $rates ) {
 $free = array();
 $is_shipping_post_only = 0;
 foreach (WC()->cart->get_cart() as $item_key => $item) {
 if ($item['data']->needs_shipping()) {
 $val = get_post_meta($item['product_id'], 'shipping_post_only', true);
 if ($val==1) {
 $is_shipping_post_only=1;
 break;
 }
 }
 }
 if ($is_shipping_post_only==1) {
 unset($rates['flat_rate:5']);
 unset($rates['flat_rate:3']);
 }
 return $rates;
}
add_filter( 'woocommerce_package_rates', 'dynamically_show_shipping_rates', 100 );

有沒有方法可以讓每一訂單金額大於指定數目,只能選用指定付款方式,如over$500 只能銀行轉帳,under 500 ,可以paypal/銀行轉帳.

解法：

add_filter('woocommerce_available_payment_gateways', 'woocs_filter_gateways', 1);

function woocs_filter_gateways($gateway_list)
{
if (WC()->cart->subtotal > 1000)
{
unset($gateway_list['cod']);
}

return $gateway_list;
}

動態增加貨運方式的方法：

/**
 * Developers can add additional flat rates based on this one via this action since @version 2.4.
 *
 * Previously there were (overly complex) options to add additional rates however this was not user.
 * friendly and goes against what Flat Rate Shipping was originally intended for.
 *
 * This example shows how you can add an extra rate based on this flat rate via custom function:
 *
 * add_action( 'woocommerce_flat_rate_shipping_add_rate', 'add_another_custom_flat_rate', 10, 2 );
 *
 * function add_another_custom_flat_rate( $method, $rate ) {
 * $new_rate = $rate;
 * $new_rate['id'] .= ':' . 'custom_rate_name'; // Append a custom ID.
 * $new_rate['label'] = 'Rushed Shipping'; // Rename to 'Rushed Shipping'.
 * $new_rate['cost'] += 2; // Add $2 to the cost.
 *
 * // Add it to WC.
 * $method->add_rate( $new_rate );
 * }.
 */

作法二號：

/**
 * Hide paid shipping rates when free shipping is available. Also remove the
 * 'Free Shipping with Signature' option when the order total < 500.
 *
 * @param array $rates Array of rates found for the package.
 * @return array
 */
function dynamically_show_shipping_rates( $rates ) {
 $free = array();
 
 $cart_subtotal = WC()->cart->subtotal;
 
 // Only display the free option and pseudo-free option when free shipping is eligible
 foreach ( $rates as $rate_id => $rate ) {
 if ( 'free_shipping' === $rate->method_id || $rate_id === 'flat_rate:7' ) {
 $free[ $rate_id ] = $rate;
 }
 }
 
 // Always remove the pseudo-free rate from $rates; it will always be in $free array if
 // if free shipping is enabled, and that will always be returned below when appropriate
 unset($rates['flat_rate:7']);
 
 return $cart_subtotal >= 500 ? $free : $rates;
}
add_filter( 'woocommerce_package_rates', 'dynamically_show_shipping_rates', 100 );

官方文章：
https://docs.woocommerce.com/document/hide-other-shipping-methods-when-free-shipping-is-available/

相關文章：
Create A WooCommerce Custom Shipping Method Plugin
https://www.cloudways.com/blog/create-woocommerce-custom-shipping-method-plugin/

但我沒有這一個檔案，所以要先去設定wp-config.php：

https://codex.wordpress.org/Debugging_in_WordPress

Example wp-config.php for Debugging

The following code, inserted in your wp-config.php file, will log all errors, notices, and warnings to a file called debug.log in the wp-content directory. It will also hide the errors so they do not interrupt page generation.

 // Enable WP_DEBUG mode
define( 'WP_DEBUG', true );

// Enable Debug logging to the /wp-content/debug.log file
define( 'WP_DEBUG_LOG', true );

// Disable display of errors and warnings 
define( 'WP_DEBUG_DISPLAY', false );
@ini_set( 'display_errors', 0 );

// Use dev versions of core JS and CSS files (only needed if you are modifying these core files)
define( 'SCRIPT_DEBUG', true );

NOTE: You must insert this BEFORE /* That's all, stop editing! Happy blogging. */ in the wp-config.php file

接下來終於看到 Error message:

[21-Apr-2017 10:45:17 UTC] WordPress 資料庫錯誤：Column ‘user_id’ cannot be null 由指令 INSERT INTO `wp_apsl_users_social_profile_details` (`user_id`, `provider_name`, `identifier`, `unique_verifier`, `email`, `first_name`, `last_name`, `profile_url`, `photo_url`, `display_name`, `description`, `gender`) VALUES (NULL, ‘facebook’, ‘1387607167994’, ‘df8c6ac9b4084ab507ea54f47ed829f26ba1’, ‘qoo@yahoo.com.tw’, ‘xx’, ‘x’, ‘https://www.facebook.com/app_scoped_user_id/1387607167994/’, ‘https://fb-s-a-a.akamaihd.net/h-ak-xap1/v/t1.0-1/c0.13.50.50/p50x50/n.jpg’, ‘xx x’, ”, ‘female’) 引發，錯誤來自 require(‘wp-load.php’), require_once(‘wp-config.php’), require_once(‘wp-settings.php’), do_action(‘init’), WP_Hook->do_action, WP_Hook->apply_filters, APSL_Lite_Class->login_check, include(‘/plugins/accesspress-social-login-lite/inc/frontend/login_check.php’), APSL_Lite_Login_Check_Class->__construct, APSL_Lite_Login_Check_Class->onFacebookLogin, APSL_Lite_Login_Check_Class::UpdateUserMeta

原來是 username 卡關，多增加下面的檢查即可：

先用這一個 validate_username( $username ) 來檢查 username. 

function validate_username( $username ) {
	$sanitized = sanitize_user( $username, true );
	$valid = ( $sanitized == $username && ! empty( $sanitized ) );

	/**
	 * Filters whether the provided username is valid or not.
	 *
	 * @since 2.0.1
	 *
	 * @param bool   $valid    Whether given username is valid.
	 * @param string $username Username to check.
	 */
	return apply_filters( 'validate_username', $valid, $username );
}

接著，不可能一筆一筆去設規格品的價格，還好 WooCommerce 很貼心提供批次更新的功能：

資料來源：
Apply the price of a WooCommerce product variation to all variations of the same product
https://www.gowp.com/blog/apply-the-price-of-a-woocommerce-product-variation-to-all-variations-of-the-same-product/

If you have a WooCommerce product with a lot of variations that are all the same price, entering/updating the price can be a little frustrating as you must update the price manually for each variation. For a product with three colour and size attributes this is only nine total variations, but if you could update the price for all nine with one click, surely you would? With a little bit of JavaScript added via an action hook, you can.

UPDATE: As it turns out, WooCommerce has added built-in support for the bulk editing of variations. While editing your product, after having added one or more variations, the “Add Variation” drop-down at the top of the Variations tab also includes a number of bulk edit options; you can set both regular and sale prices or modify either, increasing or decreasing by a percentage or set amount, for example.

Assuming you’re not using a very old version of WooCommerce, you can use the above and ignore the rest of this article.

要記得把寄信給管理者的那個寄信用的Email，在信箱的設定裡加入為「聯絡人」，不然都要到「廣告信」裡去找Email.

資料來源：https://docs.woocommerce.com/document/email-faq/

WooCommerce, and most plugins sending email, send mail by using the wp_mail() function that is a core function of WordPress.

In most cases, if email is not being sent/received, then the issue is not with WooCommerce itself, but with the core email function on your web host. See the “How does email work with WordPress?” section below.

I am getting orders, but no emails are sending!

There are multiple factors that can be the cause. Before explaining the actual mail side of the issue, please ensure that it’s not one described below.

Check for Pending Orders

• Your orders are pending. Pending orders are orders where the customer clicked “Place Order” but abandoned the payment page (depending on the payment gateway, i.e., PayPal) or had their credit card transaction declined. If you have pending orders, these orders will not generate emails.
• You have pending orders but receive payment for them via a payment gateway such as PayPal, which requires a notice to update order status on your site. In this case, you are not looking at a email issue; you are looking at an issue with your payment gateway and may need to submit a support ticket.

Check your Email Settings

Orders that are properly updating to Processing should generate an email. Another possible issue is having mistakenly disabled emails from sending. Double-check that “Enable this email notification” is ticked for order notifications. This can be found under WooCommerce > Settings > Email and click on the “processing order” email template. An additional test should be setting the Email Type to Multipart.

Your emails are broken

If emails are enabled and orders are updating to Processing, then there is most likely an issue in the email delivery to a recipient. This could be a spam blocker that classified your emails are spam and stopped them. The best way to resolve this is to sign up for an account with a dedicated SMTP provider, and an average site can usually stay within free usage accounts that are available.

How does email work?

Comparing a path an email takes to reach its destination vs. driving a car on a road trip, emails do not travel directly from point A to point B. The final destination is more like point W, and the email is bouncing from one server to another at the speed of light while being filtered at each step.

Google has put together this representation of the path an email follows. This story is specific to Gmail and delivering to a mobile device but helps explain how email works. Learn more.

How does email work with WordPress?

wp_mail() function

WooCommerce, and most plugins sending email, send mail by using the wp_mail() function that is a core function of WordPress.

Does that mean WordPress sends my email? Is WooCommerce sending the email?

Neither are sending the email. What happens is WooCommerce calls the wp_mail() function, which then requests WordPress to send the email. Because WordPress is not an email server, it typically asks PHP to send the email for it. PHP then checks for a local email server within the web server and tells that email server to send the email. Your email passes three steps before reaching your web server.

As of WooCommerce 3.0.0, a delayed CRON event is used to send emails.

If email is passed to my web server to be sent, how does a dedicated SMTP provider fit in?

By using a plugin the SMTP provider has available or the Postman SMTP plugin, the wp_mail() function reroutes the email from PHP to your SMTP provider. From there, the SMTP provider receives the request and adds your email to a queue to be sent.

What is a dedicated SMTP provider? Is that like my Gmail account?

A dedicated SMTP provider is like a web host in the sense that you have an account and use their servers. The difference is instead of hosting websites, you use their servers to send emails. Gmail is an email provider where you send and receive emails; a dedicated SMTP provider is similar to having half of Gmail, where you only send emails and not receive them.

Can I use Gmail as my SMTP provider?

Yes, but it is not ideal. Gmail will disable your account if you send emails to more than 500 unique recipients in an 24-hour period. This includes emails you send yourself and all emails your website is sending. Learn more.

Suggested Dedicated SMTP Providers

There are dedicated SMTP providers that will work for most websites. All have their own plugin on WordPress.org and can be installed from your WordPress dashboard, and have support available to help you get started.

• SendGrid (Plugin) – Send 12,000 emails free per month. （這個規則改了，沒有這個好康）
• Mailgun (Plugin) – Send 10,000 emails free per month.
• SparkPost (Plugin) – Send 100,000 emails free per month. （這個顯示我所屬地區不能申請，可能需要用VPN連去米國試看看）
• Mandrill (Plugin) – From MailChimp as a paid add-on. It costs $10/month for up to 25,000 emails. Emails are tracked and tagged for stats in the Mandrill Dashboard, and it can be used with MailChimp.

If emails are being blocked by spam filters, why is it not in my spam folder?

The spam filter is the last and final spam filter your email is filtered through, at which point it is going to spam based on your email client settings or how you mark other emails as spam. If your emails are denied by another spam filter before that, it simply is not delivered.

My contact form emails work, so why do WooCommerce emails get blocked?

Without deep investigation into server logs and tracking exact email paths, this is not a simple question to answer.

• The short version is there is a lot more to spam filters than scanning for Nigerian Princes and typical spam. Spam filters check the IP address of origin, the sending user and domain, the amount of email that IP/sender has sent, how many times emails from that sender have been marked as spam, and the wording of emails.
• The most common factor is where the email originates, which brings your overall score with spam filters down low enough that even minor differences in wording and formatting of WooCommerce emails may be flagged as spam and not sent.