如何在WordPress博客实现历史上的今天的小功能

在begin主题或者其他收费主题中，作者都代码集成了历史上的今天这样一个小功能。通过在文末显示一年前的文章。

其实也可以通过wp-today插件实现这个功能，但是wp-today插件作者柳城博客已经不再更新这个插件了。这个插件比较小，虽然是非常久远的插件，但是使用起来还是非常不错的。

这个WordPress插件对内链的优化相当不错的。所以还是非常值得拥有的。

[ad]

不过前提是文章要比较多，更新时间要比较长，最短也要一年以上。不知道是否可以实现一个月前的今天的文章功能。。这样的话，也是非常不错的。

文章部分内容是直接摘取的网友分享的两段代码。

其中一个是boke112提供的代码：

    //历史上的今天 WordPress百宝箱 https://zhuji.gd/
function wp_today(){
    global $wpdb;
    $post_year = get_the_time('Y');
    $post_month = get_the_time('m');
    $post_day = get_the_time('j');
    $sql = "select ID, year(post_date_gmt) as h_year, post_title, comment_count FROM 
            $wpdb->posts WHERE post_password = '' AND post_type = 'post' AND post_status = 'publish'
            AND year(post_date_gmt)!='$post_year' AND month(post_date_gmt)='$post_month' AND day(post_date_gmt)='$post_day'
            order by post_date_gmt DESC limit 5";
    $histtory_post = $wpdb->get_results($sql);
    if( $histtory_post ){
        foreach( $histtory_post as $post ){
            $h_year = $post->h_year;
            $h_post_title = $post->post_title;
            $h_permalink = get_permalink( $post->ID );
            $h_comments = $post->comment_count;
            $h_post .= "<li><strong>$h_year:</strong>&nbsp;&nbsp;<a href='".$h_permalink."' title='".$h_post_title."' target='_blank'>$h_post_title($h_comments)</a></li>";
        }
    }
    if ( $h_post ){
        $result = "<h2>历史上的今天:</h2><ul>".$h_post."</ul>";
    }
    return $result;
}
function wp_today_auto($content){
    if( is_single() ){
        $content = $content.wp_today();
    }
    return $content;
}
add_filter('the_content', 'wp_today_auto',9999);

<?php echo wp_today(); ?>

第二段是从 Rat's Blog分享过来的。

function wp_history_post_base($post_year, $post_month, $post_day){
    global $wpdb;
    $limit = 30;
    $order = "latest";
    if($order == "latest"){ $order = "DESC";} else { $order = '';}
    $sql = "select ID, year(post_date_gmt) as h_year, post_title, comment_count FROM 
    $wpdb->posts WHERE post_password = '' AND post_type = 'post' AND post_status = 'publish'
    AND year(post_date_gmt)!='$post_year' AND month(post_date_gmt)='$post_month' AND day(post_date_gmt)='$post_day'
    order by post_date_gmt $order limit $limit";
    $histtory_post = $wpdb->get_results($sql);
    return $histtory_post;
}
 
function wp_history_post_single(){
    $wp_history_post_content_list = '<p>%YEAR%年：<a href="%LINK%" title="%TITLE%" rel="external nofollow">%TITLE%（%COMMENTS_NUM%条评论）</a></p>';
    $wp_history_post_content_title = '<h3>历史上的今天</h3>';
    $histtory_post = wp_history_post_base(get_the_time('Y'), get_the_time('m'), get_the_time('j'));
    if($histtory_post){
        foreach( $histtory_post as $post ){
            $h_year = $post->h_year;
            $h_post_title = $post->post_title;
            $h_permalink = get_permalink( $post->ID );
            $h_comments = $post->comment_count;
            $h_post .= $wp_history_post_content_list;
            $h_post = str_replace("%YEAR%", $h_year, $h_post);
            $h_post = str_replace("%LINK%", $h_permalink, $h_post);
            $h_post = str_replace("%TITLE%", $h_post_title, $h_post);
            $h_post = str_replace("%COMMENTS_NUM%", $h_comments, $h_post);
        }
    }
    if($h_post){
        $result = $wp_history_post_content_title.$h_post;
    }
    return $result;
    wp_reset_query();
}
 
function wp_history_post_content($content){
    global $wpdb;
    if(is_single()){
        $content .= wp_history_post_single();
    }
    return $content;
}
add_action('the_content', 'wp_history_post_content');