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。

    /* 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);
    $url = "<a href="$link" title="".str_replace('%s',addcslashes($cleankeyword, '$'),__('【查看含有[%s]标签的文章】')).""";
    $url .= ' target="_blank"';
    $url .= ">".addcslashes($cleankeyword, '$')."</a>";
    $limit = rand($match_num_from,$match_num_to);
    $content = preg_replace( '|(<a[^>]+>)(.*)('.$ex_word.')(.*)(</a[^>]*>)|U'.$case, '$1$2%&&&&&%$4$5', $content);
    $content = preg_replace( '|(<img)(.*?)('.$ex_word.')(.*?)(>)|U'.$case, '$1$2%&&&&&%$4$5', $content);
    $cleankeyword = preg_quote($cleankeyword,''');
    $regEx = ''(?!((<.*?)|(<a.*?)))('. $cleankeyword . ')(?!(([^<>]*?)>)|([^>]*?</a>))'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);