WordPress展示最近更新过的文章并通知评论过的用户

// Recently Updated Posts by zwwooooo | zww.me
function recently_updated_posts($num=10,$days=7) {
   if( !$recently_updated_posts = get_option('recently_updated_posts') ) {
       query_posts('post_status=publish&orderby=modified&posts_per_page=-1');
       $i=0;
       while ( have_posts() && $i<$num ) : the_post();
           if (current_time('timestamp') - get_the_time('U') > 60*60*24*$days) {
               $i++;
               $the_title_value=get_the_title();
               $recently_updated_posts.='<li><a rel="nofollow noopener noreferrer" href="'.get_permalink().'" title="'.$the_title_value.'">'
               .$the_title_value.'</a><span class="updatetime"><br />» 修改时间: '
               .get_the_modified_time('Y.m.d G:i').'</span></li>';
           }
       endwhile;
       wp_reset_query();
       if ( !empty($recently_updated_posts) ) update_option('recently_updated_posts', $recently_updated_posts);
   }
   $recently_updated_posts=($recently_updated_posts == '') ? '<li>None data.</li>' : $recently_updated_posts;
   echo $recently_updated_posts;
}

function clear_cache_zww() {
    update_option('recently_updated_posts', ''); // 清空 recently_updated_posts
}
add_action('save_post', 'clear_cache_zww'); // 新发表文章/修改文章时触发更新

<h3>Recently Updated Posts</h3> 
<ul> 
<?php if ( function_exists('recently_updated_posts') ) recently_updated_posts(8,15); ?> 
</ul>

/** 
 * WordPress展示最近更新过的文章 并通知评论过的用户 
 * https://www.dujin.org/fenxiang/wp/9809.html 
 */ 
//修改更新文章时邮件通知评论用户 
add_action( 'submitpost_box', 'lxtx_fo_submit_box'); 
function lxtx_fo_submit_box( ){ 
    echo '<div id="fo_side-sortables" class="meta-box-sortables ui-sortable">'; 
    echo '<div id="fo_submit_box" class="postbox ">'; 
    echo '<div class="handlediv" title="点击以切换"><br></div>'; 
    echo '<h3 class="hndle"><span>邮件通知</span></h3>'; 
    echo '<div class="inside"><div class="submitbox">'; 
    echo ' <div style="padding: 10px 10px 0;text-align: left;"><label class="selectit" title="慎用此功能，重要文章才勾选嘛，以免引起读者反感哈"><input type="checkbox" name="FO_emaill_report_user" value="true" title="勾选此项，将邮件通知本文所有评论者"/>邮通知本文所有评论者</label></div>'; 
    echo '</div></div>'; 
    echo '</div>'; 
    echo '</div>'; 
} 
//开始 
add_action( 'publish_post', 'lxtx_fo_emaill_report_users' ); 
function lxtx_fo_emaill_report_users($post_ID) 
{
    //如果未勾选保存，不进行任何操作 
    if($_POST['FO_emaill_report_user'] != 'true'){ 
        return; 
    } 

    //修订版本不通知，以免滥用 
    if( wp_is_post_revision($post_ID) ){ 
        return; 
    } 

    //获取wp数据操作类 
    global $wpdb,$post; 
    // 读数据库，获取文章的所有用户的email并且不重复 
    $emailauthor != '你自己的邮箱'; 
    $wp_user_emails = $wpdb->get_results("SELECT DISTINCT comment_author, comment_author_email FROM $wpdb->comments WHERE TRIM(comment_author_email) IS NOT NULL AND TRIM(comment_author_email) != '' AND TRIM(comment_author_email) != '$emailauthor' AND comment_post_ID = $post->ID"); 

    // 获取博客名称 
    $blogname = wp_specialchars_decode(get_option('blogname'), ENT_QUOTES); 
    // 获取博客URL 
    $blogurl = get_bloginfo("siteurl"); 

    //文章链接 
    $post_link = get_permalink($post_ID); 
    //文章标题$post -> post_title 
    $post_title = strip_tags($_POST['post_title']); 
    //文章内容$post->post_content 
    $post_content = strip_tags($_POST['post_content']); 
    //文章摘要 
    $output = preg_replace('/^(?:[\x00-\x7F]|[\xC0-\xFF][\x80-\xBF]+){0,0}((?:[\x00-\x7F]|[\xC0-\xFF][\x80-\xBF]+){0,200}).*/s','\1',$post_content).'......'; 

    //邮件头，以免乱码 
    $message_headers = "Content-Type: text/html; charset=\&;utf-8\&;\n"; 
    // 邮件标题 
    $subject = '您曾经来访过的《'.$post_title.'》文章更新通知。'; 

    foreach ( $wp_user_emails as $wp_user_email ) 
    { 
        // 邮件内容 
        $message = ' 
        <div style="MARGIN-RIGHT: auto; MARGIN-LEFT: auto;"> 
            <strong style="line-height: 1.5; font-family:Microsoft YaHei;"> 
                亲爱的'.$wp_user_email->comment_author.'： 
            </strong> 
            <p style="FONT-SIZE: 14px; PADDING-TOP: 6px"> 
                您曾经来访过的《'.$post_title.'》有更新，博主觉得有必要通知您，希望不会骚扰到您。 
            </p> 
            <p style="FONT-SIZE: 14px; PADDING-TOP: 6px"> 
                文章标题：<a title="'.$post_title.'" rel="nofollow noopener noreferrer" href="'.$post_link.'" target="_top">'.$post_title.'</a> 
                <br/> 
                文章摘要：'.$output.' 
            </p> 
            <p style="FONT-SIZE: 14px; PADDING-TOP: 6px"> 
                您可以点击链接 
                <a rel="nofollow noopener noreferrer" href="'.$blogurl.'" style="line-height: 1.5;">'.$blogname.'</a> 
                > 
                <a title="'.$post_title.'" rel="nofollow noopener noreferrer" href="'.$post_link.'" target="_top">'.$post_title.'</a> 
                详细查看 
            </p> 
            <p style="font-size: 14px; padding-top: 6px; text-align: left;"> 
                <span style="line-height: 1.5; color: rgb(153, 153, 153);"> 
                    来自： 
                </span> 
                <a rel="nofollow noopener noreferrer" href="'.$blogurl.'" style="line-height: 1.5;">'.$blogname.'</a> 
            </p> 
            <div style="font-size: 12px; border-top-color: rgb(204, 204, 204); border-top-width: 1px; border-top-style: solid; height: 35px; width: 500px; color: rgb(102, 102, 102); line-height: 35px; background-color: rgb(245, 245, 245);"> 
                该邮件为系统发送邮件，请勿直接回复！如有打扰，请向博主留言反映。灰常感谢您的阅读！ 
            </div> 
        </div>'; 
        wp_mail($wp_user_email->comment_author_email, $subject, $message, $message_headers); 
    } 
}