WordPress 标签自动添加内链、文章自动生成标签

WordPress标签是一个好功能，善用标签不但可以加强文章间的关联性提升用户体验，也可以借助标签加强站内SEO内链。
以下内容使用方法: 将代码添加至主题functions.php文章中即可。

WordPress文章自动添加标签

/* 自动为文章添加标签 */
add_action('save_post', 'auto_add_tags');
function auto_add_tags(){
    $tags = get_tags( array('hide_empty' => false) );
    $post_id = get_the_ID();
    $post_content = get_post($post_id)->post_content;
    if ($tags) {
        foreach ( $tags as $tag ) {
            // 如果文章内容出现了已使用过的标签，自动添加这些标签
            if ( strpos($post_content, $tag->name) !== false)
                wp_set_post_tags( $post_id, $tag->name, true );
        }
    }

WordPress 标签自动添加内链

/* 自动为文章内的标签添加内链 */
$match_num_from = 1;        //一篇文章中同一个标签少于几次不自动链接
$match_num_to = 1;      //一篇文章中同一个标签最多自动链接几次
function tag_sort($a, $b){
    if ( $a->name == $b->name ) return 0;
    return ( strlen($a->name) > strlen($b->name) ) ? -1 : 1;
}
function tag_link($content){
    global $match_num_from,$match_num_to;
        $posttags = get_the_tags();
        if ($posttags) {
            usort($posttags, "tag_sort");
            foreach($posttags as $tag) {
                $link = get_tag_link($tag->term_id);
                $keyword = $tag->name;
                $cleankeyword = stripslashes($keyword);
                $url = "";
                $limit = rand($match_num_from,$match_num_to);
                $content = preg_replace( '|(]+>)(.*)('.$ex_word.')(.*)([^>]*>)|U'.$case, '$1$2$4$5', $content);
                $content = preg_replace( '|()|U'.$case, '$1$2$4$5', $content);
                $cleankeyword = preg_quote($cleankeyword,''');
                $regEx = ''(?!((<. .>]*?)>)|([^>]*?))'s' . $case;
                $content = preg_replace($regEx,$url,$content,$limit);
                $content = str_replace( '', stripslashes($ex_word), $content);
            }
        }
    return $content;
}
add_filter('the_content','tag_link',1);