我在wordpress API上做了一些工作，我想尝试包括<meta>-标记到我网站的头部区域。

This is my code (works everything fine!):

class dmd_noindex_options_page{
    function __construct() {
        add_action( \'wp_head\', array( $this, \'set_meta\') );
    }
    function set_meta(){
       $pages = get_option(\'dmd_noindex_pages\');
       $pages_id = explode(\',\', $pages);           
       for($i = 0; count($pages_id) > $i; $i++){
           if(is_page($pages_id[$i])){
              echo \'<META NAME="ROBOTS" CONTENT="NOINDEX, NOFOLLOW">\';
           }
        }
    }
}
new dmd_noindex_options_page;

My problem:

我使用WP插件Yoast SEO，如果我查看一下我的网站代码，我会在上面看到我的<meta>-标签

<!-- This site is optimized with the Yoast SEO plugin v2.3.5 - https://yoast.com/wordpress/plugins/seo/ -->
<meta name="robots" content="noindex,follow"/>
<meta name="description" content="Impressum von EK Immobilien und Kontaktaufnahme"/>
<link rel="canonical" href="http://ek.dimadirekt.com/de/impressum/" />
<meta property="og:locale" content="de_DE" />
<meta property="og:type" content="article" />
<meta property="og:title" content="Impressum -" />
<meta property="og:description" content="Impressum von EK Immobilien und Kontaktaufnahme" />
<meta property="og:url" content="http://ek.dimadirekt.com/de/impressum/" />
<meta name="twitter:card" content="summary"/>
<meta name="twitter:description" content="Impressum von EK Immobilien und Kontaktaufnahme"/>
<meta name="twitter:title" content="Impressum -"/>
<!-- / Yoast SEO plugin. -->

我don\'t want 停用此Yoast SEO插件！我试图为我的add_action 但这行不通。

E、 g.：

add_action( \'wp_head\', array( $this, \'set_meta\', 2,1) );

My question is:

如何包括我的<meta>-标签位于<meta>-Yoast SEO插件的标签？我可以在所有插件中首先包含我的代码吗？

add_filter( \'wpseo_robots\', function( $content )
{
        // your logic here ...
        return $content;    
} );

function my_disallow_directory() {
    echo "User-agent: *" . PHP_EOL;
    echo "Disallow: /path/to/your/directory/" . PHP_EOL;
}
add_action( \'do_robotstxt\', \'my_disallow_directory\' );