代码实现给Wordpress站外链接自动nofollow和新窗口

为站外链接一个个加nofollow还是比较麻烦的.通过代码能否实现给站外链接自动添加nofollow和在新窗口打开, 如果链接已经有rel="nofollow" 和target="_blank"属性, 则不会再次添加.

添加以下代码到WordPress主题的functions.php文件即可

//出站链接自动添加nofollow和在新窗口打开
add_filter( 'the_content', 'auto_nofollow_for_external_link_wmsoho');
function auto_nofollow_for_external_link_wmsoho( $content ) {
    $regexp = "<a\s[^>]*href=(\"??)([^\" >]*?)\\1[^>]*>";
    if(preg_match_all("/$regexp/siU", $content, $matches, PREG_SET_ORDER)) {
        if( !empty($matches) ) {
            $srcUrl = get_option('siteurl');
            for ($i=0; $i < count($matches); $i++)
            {
                $tag = $matches[$i][0];
                $tag2 = $matches[$i][0];
                $url = $matches[$i][0];
 
                $noFollow = '';
 
                $pattern = '/target\s*=\s*"\s*_blank\s*"/';
                preg_match($pattern, $tag2, $match, PREG_OFFSET_CAPTURE);
                if( count($match) < 1 )
                    $noFollow .= ' target="_blank" ';
 
                $pattern = '/rel\s*=\s*"\s*[n|d]ofollow\s*"/';
                preg_match($pattern, $tag2, $match, PREG_OFFSET_CAPTURE);
                if( count($match) < 1 )
                    $noFollow .= ' rel="nofollow" ';
 
                $pos = strpos($url,$srcUrl);
                if ($pos === false) {
                    $tag = rtrim ($tag,'>');
                    $tag .= $noFollow.'>';
                    $content = str_replace($tag2,$tag,$content);
                }
            }
        }
    }
    $content = str_replace(']]>', ']]>', $content);
    return $content;
}