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   1  <?php
   2  /**
   3   * Robots template functions.
   4   *
   5   * @package WordPress
   6   * @subpackage Robots
   7   * @since 5.7.0
   8   */
   9  
  10  /**
  11   * Displays the robots meta tag as necessary.
  12   *
  13   * Gathers robots directives to include for the current context, using the
  14   * {@see 'wp_robots'} filter. The directives are then sanitized, and the
  15   * robots meta tag is output if there is at least one relevant directive.
  16   *
  17   * @since 5.7.0
  18   * @since 5.7.1 No longer prevents specific directives to occur together.
  19   */
  20  function wp_robots() {
  21      /**
  22       * Filters the directives to be included in the 'robots' meta tag.
  23       *
  24       * The meta tag will only be included as necessary.
  25       *
  26       * @since 5.7.0
  27       *
  28       * @param array $robots Associative array of directives. Every key must be the name of the directive, and the
  29       *                      corresponding value must either be a string to provide as value for the directive or a
  30       *                      boolean `true` if it is a boolean directive, i.e. without a value.
  31       */
  32      $robots = apply_filters( 'wp_robots', array() );
  33  
  34      $robots_strings = array();
  35      foreach ( $robots as $directive => $value ) {
  36          if ( is_string( $value ) ) {
  37              // If a string value, include it as value for the directive.
  38              $robots_strings[] = "{$directive}:{$value}";
  39          } elseif ( $value ) {
  40              // Otherwise, include the directive if it is truthy.
  41              $robots_strings[] = $directive;
  42          }
  43      }
  44  
  45      if ( empty( $robots_strings ) ) {
  46          return;
  47      }
  48  
  49      echo "<meta name='robots' content='" . esc_attr( implode( ', ', $robots_strings ) ) . "' />\n";
  50  }
  51  
  52  /**
  53   * Adds `noindex` to the robots meta tag if required by the site configuration.
  54   *
  55   * If a blog is marked as not being public then noindex will be output to
  56   * tell web robots not to index the page content. Add this to the
  57   * {@see 'wp_robots'} filter.
  58   *
  59   * Typical usage is as a {@see 'wp_robots'} callback:
  60   *
  61   *     add_filter( 'wp_robots', 'wp_robots_noindex' );
  62   *
  63   * @since 5.7.0
  64   *
  65   * @see wp_robots_no_robots()
  66   *
  67   * @param array $robots Associative array of robots directives.
  68   * @return array Filtered robots directives.
  69   */
  70  function wp_robots_noindex( array $robots ) {
  71      if ( ! get_option( 'blog_public' ) ) {
  72          return wp_robots_no_robots( $robots );
  73      }
  74  
  75      return $robots;
  76  }
  77  
  78  /**
  79   * Adds `noindex` to the robots meta tag for embeds.
  80   *
  81   * Typical usage is as a {@see 'wp_robots'} callback:
  82   *
  83   *     add_filter( 'wp_robots', 'wp_robots_noindex_embeds' );
  84   *
  85   * @since 5.7.0
  86   *
  87   * @see wp_robots_no_robots()
  88   *
  89   * @param array $robots Associative array of robots directives.
  90   * @return array Filtered robots directives.
  91   */
  92  function wp_robots_noindex_embeds( array $robots ) {
  93      if ( is_embed() ) {
  94          return wp_robots_no_robots( $robots );
  95      }
  96  
  97      return $robots;
  98  }
  99  
 100  /**
 101   * Adds `noindex` to the robots meta tag if a search is being performed.
 102   *
 103   * If a search is being performed then noindex will be output to
 104   * tell web robots not to index the page content. Add this to the
 105   * {@see 'wp_robots'} filter.
 106   *
 107   * Typical usage is as a {@see 'wp_robots'} callback:
 108   *
 109   *     add_filter( 'wp_robots', 'wp_robots_noindex_search' );
 110   *
 111   * @since 5.7.0
 112   *
 113   * @see wp_robots_no_robots()
 114   *
 115   * @param array $robots Associative array of robots directives.
 116   * @return array Filtered robots directives.
 117   */
 118  function wp_robots_noindex_search( array $robots ) {
 119      if ( is_search() ) {
 120          return wp_robots_no_robots( $robots );
 121      }
 122  
 123      return $robots;
 124  }
 125  
 126  /**
 127   * Adds `noindex` to the robots meta tag.
 128   *
 129   * This directive tells web robots not to index the page content.
 130   *
 131   * Typical usage is as a {@see 'wp_robots'} callback:
 132   *
 133   *     add_filter( 'wp_robots', 'wp_robots_no_robots' );
 134   *
 135   * @since 5.7.0
 136   *
 137   * @param array $robots Associative array of robots directives.
 138   * @return array Filtered robots directives.
 139   */
 140  function wp_robots_no_robots( array $robots ) {
 141      $robots['noindex'] = true;
 142  
 143      if ( get_option( 'blog_public' ) ) {
 144          $robots['follow'] = true;
 145      } else {
 146          $robots['nofollow'] = true;
 147      }
 148  
 149      return $robots;
 150  }
 151  
 152  /**
 153   * Adds `noindex` and `noarchive` to the robots meta tag.
 154   *
 155   * This directive tells web robots not to index or archive the page content and
 156   * is recommended to be used for sensitive pages.
 157   *
 158   * Typical usage is as a {@see 'wp_robots'} callback:
 159   *
 160   *     add_filter( 'wp_robots', 'wp_robots_sensitive_page' );
 161   *
 162   * @since 5.7.0
 163   *
 164   * @param array $robots Associative array of robots directives.
 165   * @return array Filtered robots directives.
 166   */
 167  function wp_robots_sensitive_page( array $robots ) {
 168      $robots['noindex']   = true;
 169      $robots['noarchive'] = true;
 170      return $robots;
 171  }
 172  
 173  /**
 174   * Adds `max-image-preview:large` to the robots meta tag.
 175   *
 176   * This directive tells web robots that large image previews are allowed to be
 177   * displayed, e.g. in search engines, unless the blog is marked as not being public.
 178   *
 179   * Typical usage is as a {@see 'wp_robots'} callback:
 180   *
 181   *     add_filter( 'wp_robots', 'wp_robots_max_image_preview_large' );
 182   *
 183   * @since 5.7.0
 184   *
 185   * @param array $robots Associative array of robots directives.
 186   * @return array Filtered robots directives.
 187   */
 188  function wp_robots_max_image_preview_large( array $robots ) {
 189      if ( get_option( 'blog_public' ) ) {
 190          $robots['max-image-preview'] = 'large';
 191      }
 192      return $robots;
 193  }