W!K!

最近，我们的 WordPress 网站上搭建的 WooCommerce 店铺经常收到 Delivery incomplete 的邮件报错，点进去发现基本都如下的报错情况：

意思就是邮件投递失败，查询后发现是机器人使用了随机的域名注册了店铺账户，收件箱内经常出现如下图的邮件提醒。

作为一个 商城网站，我们不能关停用户注册的功能，并且也使用了人机验证的服务，但是任然没法避免机器人注册泛滥，因此我们需要加上注册的限制功能。
我先简单搜索了下，确实有相关的插件可以解决此类问题，但是为了避免这类插件带来一些不必要的功能，因此我们采用自行添加代码到子主题的 functions.php 中实现相关的功能。

关键词设置界面

首先需要一个可以自定义关键词和限制规则的设置界面，设置的选项包括关键词设置和限制三级域名的邮箱注册。

// Register a new settings menu in WordPress admin
function register_limits_settings_menu() {
  add_options_page( 'Registration Keywords Options', 'Registration Keywords', 'manage_options', 'registration-limits', 'registration_limits_settings_page' );
}
add_action( 'admin_menu', 'register_limits_settings_menu' );

// Define the layout and fields of the settings page
function registration_limits_settings_page() {
  ?>
  <div>
    <?php screen_icon(); ?>
    <h2>Registration Keywords Settings</h2>
    <form method="post" action="options.php">
      <?php settings_fields( 'registration_limits_options' ); ?>
      <?php do_settings_sections( 'registration_limits' ); ?>
      <?php submit_button(); ?>
    </form>
  </div>
  <?php
}


// Register the settings fields with WordPress
function register_keywords_settings_fields() {
    add_settings_section( 'registration_limits_section', '', '', 'registration_limits' );
    add_settings_field( 'restricted_keywords', 'Restricted Keywords', 'restricted_keywords_callback', 'registration_limits', 'registration_limits_section' );
    add_settings_field( 'ignore_3level_domain', 'Ignore 3-Level Domain Names', 'ignore_3level_domain_callback', 'registration_limits', 'registration_limits_section' );
    register_setting( 'registration_limits_options', 'restricted_keywords', 'sanitize_text_field' );
    register_setting( 'registration_limits_options', 'ignore_3level_domain', 'absint' );
  }
  add_action( 'admin_init', 'register_keywords_settings_fields' );
  
  // Define the callback to display the "Restricted Keywords" field on the settings page
  function restricted_keywords_callback() {
    $restricted_keywords = get_option( 'restricted_keywords', '' );
    ?>
    <input type="text" id="restricted_keywords" name="restricted_keywords" value="<?php echo esc_attr( $restricted_keywords ); ?>" />
    <p class="description">Enter a comma separated list of keywords to restrict during registration.</p>
    <?php
  }

// Define the callback to display the "Ignore 3-Level Domain Names" checkbox on the settings page
function ignore_3level_domain_callback() {
  $ignore_3level_domain = get_option( 'ignore_3level_domain', 0 );
  ?>
  <input type="checkbox" id="ignore_3level_domain" name="ignore_3level_domain" value="1" <?php checked( $ignore_3level_domain, 1 ); ?> />
  <label for="ignore_3level_domain">Ignore registration if email address includes 3-level domain name.</label>
  <?php
}

限制用户注册

只要满足以上2个条件的注册信息，都需要被屏蔽掉，我们需要采用 woocommerce_registration_errors 的 hook 进行限制。

// Validate the registration form and restrict based on keyword and 3-level domain name conditions
function restricted_keyword_in_email($errors, $sanitized_user_login, $user_email)
{
    $ignore_3level_domain = get_option('ignore_3level_domain', 0);

    // ignore 3-level domain name condition
    if ($ignore_3level_domain == 1) {
        $email_parts = explode("@", $user_email);
        $domain_parts = explode(".", $email_parts[1]);
        if (count($domain_parts) == 3) {
            $errors->add('email_invalid', __('Invalid email address containing 3-level domain name.'));
        }
    }

    // restrict keyword condition
    $restricted_keywords = get_option('restricted_keywords', '');
    $restricted_keywords_array = explode(',', $restricted_keywords);

    foreach ($restricted_keywords_array as $restricted_keyword) {
        $restricted_keyword = trim($restricted_keyword);
        if (strpos($user_email, $restricted_keyword) !== false) { // check for presence of keyword
            $errors->add('email_invalid', __('Invalid email address containing restricted keyword.')); // throw error
        }
    }
    return $errors;
}
add_filter('woocommerce_registration_errors', 'restricted_keyword_in_email', 10, 3);

拦截效果演示

1. 注册限制关键词
   

2. 注册限制三级域名