<?php
namespace Yoast\WP\SEO\Integrations\Front_End;
use Yoast\WP\SEO\Conditionals\Front_End_Conditional;
use Yoast\WP\SEO\Helpers\Robots_Helper;
use Yoast\WP\SEO\Integrations\Integration_Interface;
/**
* Class Indexing_Controls.
*/
class Indexing_Controls implements Integration_Interface {
/**
* The robots helper.
*
* @var Robots_Helper
*/
protected $robots;
/**
* Returns the conditionals based in which this loadable should be active.
*
* @return array
*/
public static function get_conditionals() {
return [ Front_End_Conditional::class ];
}
/**
* The constructor.
*
* @codeCoverageIgnore Sets the dependencies.
*
* @param Robots_Helper $robots The robots helper.
*/
public function __construct( Robots_Helper $robots ) {
$this->robots = $robots;
}
/**
* Initializes the integration.
*
* This is the place to register hooks and filters.
*
* @codeCoverageIgnore
*
* @return void
*/
public function register_hooks() {
// The option `blog_public` is set in Settings > Reading > Search Engine Visibility.
if ( (string) \get_option( 'blog_public' ) === '0' ) {
\add_filter( 'wpseo_robots_array', [ $this->robots, 'set_robots_no_index' ] );
}
\add_action( 'template_redirect', [ $this, 'noindex_robots' ] );
\add_filter( 'loginout', [ $this, 'nofollow_link' ] );
\add_filter( 'register', [ $this, 'nofollow_link' ] );
// Remove actions that we will handle through our wpseo_head call, and probably change the output of.
\remove_action( 'wp_head', 'rel_canonical' );
\remove_action( 'wp_head', 'index_rel_link' );
\remove_action( 'wp_head', 'start_post_rel_link' );
\remove_action( 'wp_head', 'adjacent_posts_rel_link_wp_head' );
\remove_action( 'wp_head', 'noindex', 1 );
}
/**
* Sends a Robots HTTP header preventing URL from being indexed in the search results while allowing search engines
* to follow the links in the object at the URL.
*
* @return bool Boolean indicating whether the noindex header was sent.
*/
public function noindex_robots() {
if ( ! \is_robots() ) {
return false;
}
return $this->set_robots_header();
}
/**
* Adds rel="nofollow" to a link, only used for login / registration links.
*
* @param string $input The link element as a string.
*
* @return string
*/
public function nofollow_link( $input ) {
return \str_replace( '<a ', '<a rel="nofollow" ', $input );
}
/**
* Sets the x-robots-tag to noindex follow.
*
* @codeCoverageIgnore Too difficult to test.
*
* @return bool
*/
protected function set_robots_header() {
if ( \headers_sent() === false ) {
\header( 'X-Robots-Tag: noindex, follow', true );
return true;
}
return false;
}
}