/wp-includes/class-wp.php

<?php 
/** 
 * WordPress environment setup class. 
 * 
 * @package WordPress 
 * @since 2.0.0 
 */ 
class WP { 
  /** 
   * Public query variables. 
   * 
   * Long list of public query variables. 
   * 
   * @since 2.0.0 
   * @access public 
   * @var array 
   */ 
  public $public_query_vars = array('m', 'p', 'posts', 'w', 'cat', 'withcomments', 'withoutcomments', 's', 'search', 'exact', 'sentence', 'calendar', 'page', 'paged', 'more', 'tb', 'pb', 'author', 'order', 'orderby', 'year', 'monthnum', 'day', 'hour', 'minute', 'second', 'name', 'category_name', 'tag', 'feed', 'author_name', 'static', 'pagename', 'page_id', 'error', 'attachment', 'attachment_id', 'subpost', 'subpost_id', 'preview', 'robots', 'taxonomy', 'term', 'cpage', 'post_type', 'embed' ); 
 
  /** 
   * Private query variables. 
   * 
   * Long list of private query variables. 
   * 
   * @since 2.0.0 
   * @access public 
   * @var array 
   */ 
  public $private_query_vars = array( 'offset', 'posts_per_page', 'posts_per_archive_page', 'showposts', 'nopaging', 'post_type', 'post_status', 'category__in', 'category__not_in', 'category__and', 'tag__in', 'tag__not_in', 'tag__and', 'tag_slug__in', 'tag_slug__and', 'tag_id', 'post_mime_type', 'perm', 'comments_per_page', 'post__in', 'post__not_in', 'post_parent', 'post_parent__in', 'post_parent__not_in', 'title', 'fields' ); 
 
  /** 
   * Extra query variables set by the user. 
   * 
   * @since 2.1.0 
   * @access public 
   * @var array 
   */ 
  public $extra_query_vars = array(); 
 
  /** 
   * Query variables for setting up the WordPress Query Loop. 
   * 
   * @since 2.0.0 
   * @access public 
   * @var array 
   */ 
  public $query_vars; 
 
  /** 
   * String parsed to set the query variables. 
   * 
   * @since 2.0.0 
   * @access public 
   * @var string 
   */ 
  public $query_string; 
 
  /** 
   * The request path, e.g. 2015/05/06. 
   * 
   * @since 2.0.0 
   * @access public 
   * @var string 
   */ 
  public $request; 
 
  /** 
   * Rewrite rule the request matched. 
   * 
   * @since 2.0.0 
   * @access public 
   * @var string 
   */ 
  public $matched_rule; 
 
  /** 
   * Rewrite query the request matched. 
   * 
   * @since 2.0.0 
   * @access public 
   * @var string 
   */ 
  public $matched_query; 
 
  /** 
   * Whether already did the permalink. 
   * 
   * @since 2.0.0 
   * @access public 
   * @var bool 
   */ 
  public $did_permalink = false; 
 
  /** 
   * Add name to list of public query variables. 
   * 
   * @since 2.1.0 
   * @access public 
   * 
   * @param string $qv Query variable name. 
   */ 
  public function add_query_var($qv) { 
      if ( !in_array($qv, $this->public_query_vars) ) 
          $this->public_query_vars[] = $qv; 
  } 
 
  /** 
   * Removes a query variable from a list of public query variables. 
   * 
   * @since 4.5.0 
   * @access public 
   * 
   * @param string $name Query variable name. 
   */ 
  public function remove_query_var( $name ) { 
      $this->public_query_vars = array_diff( $this->public_query_vars, array( $name ) ); 
  } 
 
  /** 
   * Set the value of a query variable. 
   * 
   * @since 2.3.0 
   * @access public 
   * 
   * @param string $key Query variable name. 
   * @param mixed $value Query variable value. 
   */ 
  public function set_query_var($key, $value) { 
      $this->query_vars[$key] = $value; 
  } 
 
  /** 
   * Parse request to find correct WordPress query. 
   * 
   * Sets up the query variables based on the request. There are also many 
   * filters and actions that can be used to further manipulate the result. 
   * 
   * @since 2.0.0 
   * @access public 
   * 
   * @global WP_Rewrite $wp_rewrite 
   * 
   * @param array|string $extra_query_vars Set the extra query variables. 
   */ 
  public function parse_request($extra_query_vars = '') { 
      global $wp_rewrite; 
 
      /** 
       * Filters whether to parse the request. 
       * 
       * @since 3.5.0 
       * 
       * @param bool         $bool             Whether or not to parse the request. Default true. 
       * @param WP           $this             Current WordPress environment instance. 
       * @param array|string $extra_query_vars Extra passed query variables. 
       */ 
      if ( ! apply_filters( 'do_parse_request', true, $this, $extra_query_vars ) ) 
          return; 
 
      $this->query_vars = array(); 
      $post_type_query_vars = array(); 
 
      if ( is_array( $extra_query_vars ) ) { 
          $this->extra_query_vars = & $extra_query_vars; 
      } elseif ( ! empty( $extra_query_vars ) ) { 
          parse_str( $extra_query_vars, $this->extra_query_vars ); 
      } 
      // Process PATH_INFO, REQUEST_URI, and 404 for permalinks. 
 
      // Fetch the rewrite rules. 
      $rewrite = $wp_rewrite->wp_rewrite_rules(); 
 
      if ( ! empty($rewrite) ) { 
          // If we match a rewrite rule, this will be cleared. 
          $error = '404'; 
          $this->did_permalink = true; 
 
          $pathinfo = isset( $_SERVER['PATH_INFO'] ) ? $_SERVER['PATH_INFO'] : ''; 
          list( $pathinfo ) = explode( '?', $pathinfo ); 
          $pathinfo = str_replace( "%", "%25", $pathinfo ); 
 
          list( $req_uri ) = explode( '?', $_SERVER['REQUEST_URI'] ); 
          $self = $_SERVER['PHP_SELF']; 
          $home_path = trim( parse_url( home_url(), PHP_URL_PATH ), '/' ); 
          $home_path_regex = sprintf( '|^%s|i', preg_quote( $home_path, '|' ) ); 
 
          // Trim path info from the end and the leading home path from the 
          // front. For path info requests, this leaves us with the requesting 
          // filename, if any. For 404 requests, this leaves us with the 
          // requested permalink. 
          $req_uri = str_replace($pathinfo, '', $req_uri); 
          $req_uri = trim($req_uri, '/'); 
          $req_uri = preg_replace( $home_path_regex, '', $req_uri ); 
          $req_uri = trim($req_uri, '/'); 
          $pathinfo = trim($pathinfo, '/'); 
          $pathinfo = preg_replace( $home_path_regex, '', $pathinfo ); 
          $pathinfo = trim($pathinfo, '/'); 
          $self = trim($self, '/'); 
          $self = preg_replace( $home_path_regex, '', $self ); 
          $self = trim($self, '/'); 
 
          // The requested permalink is in $pathinfo for path info requests and 
          //  $req_uri for other requests. 
          if ( ! empty($pathinfo) && !preg_match('|^.*' . $wp_rewrite->index . '$|', $pathinfo) ) { 
              $requested_path = $pathinfo; 
          } else { 
              // If the request uri is the index, blank it out so that we don't try to match it against a rule. 
              if ( $req_uri == $wp_rewrite->index ) 
                  $req_uri = ''; 
              $requested_path = $req_uri; 
          } 
          $requested_file = $req_uri; 
 
          $this->request = $requested_path; 
 
          // Look for matches. 
          $request_match = $requested_path; 
          if ( empty( $request_match ) ) { 
              // An empty request could only match against ^$ regex 
              if ( isset( $rewrite['$'] ) ) { 
                  $this->matched_rule = '$'; 
                  $query = $rewrite['$']; 
                  $matches = array(''); 
              } 
          } else { 
              foreach ( (array) $rewrite as $match => $query ) { 
                  // If the requested file is the anchor of the match, prepend it to the path info. 
                  if ( ! empty($requested_file) && strpos($match, $requested_file) === 0 && $requested_file != $requested_path ) 
                      $request_match = $requested_file . '/' . $requested_path; 
 
                  if ( preg_match("#^$match#", $request_match, $matches) || 
                      preg_match("#^$match#", urldecode($request_match), $matches) ) { 
 
                      if ( $wp_rewrite->use_verbose_page_rules && preg_match( '/pagename=\$matches\[([0-9]+)\]/', $query, $varmatch ) ) { 
                          // This is a verbose page match, let's check to be sure about it. 
                          $page = get_page_by_path( $matches[ $varmatch[1] ] ); 
                          if ( ! $page ) { 
                               continue; 
                          } 
 
                          $post_status_obj = get_post_status_object( $page->post_status ); 
                          if ( ! $post_status_obj->public && ! $post_status_obj->protected 
                              && ! $post_status_obj->private && $post_status_obj->exclude_from_search ) { 
                              continue; 
                          } 
                      } 
 
                      // Got a match. 
                      $this->matched_rule = $match; 
                      break; 
                  } 
              } 
          } 
 
          if ( isset( $this->matched_rule ) ) { 
              // Trim the query of everything up to the '?'. 
              $query = preg_replace("!^.+\?!", '', $query); 
 
              // Substitute the substring matches into the query. 
              $query = addslashes(WP_MatchesMapRegex::apply($query, $matches)); 
 
              $this->matched_query = $query; 
 
              // Parse the query. 
              parse_str($query, $perma_query_vars); 
 
              // If we're processing a 404 request, clear the error var since we found something. 
              if ( '404' == $error ) 
                  unset( $error, $_GET['error'] ); 
          } 
 
          // If req_uri is empty or if it is a request for ourself, unset error. 
          if ( empty($requested_path) || $requested_file == $self || strpos($_SERVER['PHP_SELF'], 'wp-admin/') !== false ) { 
              unset( $error, $_GET['error'] ); 
 
              if ( isset($perma_query_vars) && strpos($_SERVER['PHP_SELF'], 'wp-admin/') !== false ) 
                  unset( $perma_query_vars ); 
 
              $this->did_permalink = false; 
          } 
      } 
 
      /** 
       * Filters the query variables whitelist before processing. 
       * 
       * Allows (publicly allowed) query vars to be added, removed, or changed prior 
       * to executing the query. Needed to allow custom rewrite rules using your own arguments 
       * to work, or any other custom query variables you want to be publicly available. 
       * 
       * @since 1.5.0 
       * 
       * @param array $public_query_vars The array of whitelisted query variables. 
       */ 
      $this->public_query_vars = apply_filters( 'query_vars', $this->public_query_vars ); 
 
      foreach ( get_post_types( array(), 'objects' ) as $post_type => $t ) { 
          if ( is_post_type_viewable( $t ) && $t->query_var ) { 
              $post_type_query_vars[$t->query_var] = $post_type; 
          } 
      } 
 
      foreach ( $this->public_query_vars as $wpvar ) { 
          if ( isset( $this->extra_query_vars[$wpvar] ) ) 
              $this->query_vars[$wpvar] = $this->extra_query_vars[$wpvar]; 
          elseif ( isset( $_POST[$wpvar] ) ) 
              $this->query_vars[$wpvar] = $_POST[$wpvar]; 
          elseif ( isset( $_GET[$wpvar] ) ) 
              $this->query_vars[$wpvar] = $_GET[$wpvar]; 
          elseif ( isset( $perma_query_vars[$wpvar] ) ) 
              $this->query_vars[$wpvar] = $perma_query_vars[$wpvar]; 
 
          if ( !empty( $this->query_vars[$wpvar] ) ) { 
              if ( ! is_array( $this->query_vars[$wpvar] ) ) { 
                  $this->query_vars[$wpvar] = (string) $this->query_vars[$wpvar]; 
              } else { 
                  foreach ( $this->query_vars[$wpvar] as $vkey => $v ) { 
                      if ( !is_object( $v ) ) { 
                          $this->query_vars[$wpvar][$vkey] = (string) $v; 
                      } 
                  } 
              } 
 
              if ( isset($post_type_query_vars[$wpvar] ) ) { 
                  $this->query_vars['post_type'] = $post_type_query_vars[$wpvar]; 
                  $this->query_vars['name'] = $this->query_vars[$wpvar]; 
              } 
          } 
      } 
 
      // Convert urldecoded spaces back into + 
      foreach ( get_taxonomies( array() , 'objects' ) as $taxonomy => $t ) 
          if ( $t->query_var && isset( $this->query_vars[$t->query_var] ) ) 
              $this->query_vars[$t->query_var] = str_replace( ' ', '+', $this->query_vars[$t->query_var] ); 
 
      // Don't allow non-publicly queryable taxonomies to be queried from the front end. 
      if ( ! is_admin() ) { 
          foreach ( get_taxonomies( array( 'publicly_queryable' => false ), 'objects' ) as $taxonomy => $t ) { 
              /** 
               * Disallow when set to the 'taxonomy' query var. 
               * Non-publicly queryable taxonomies cannot register custom query vars. See register_taxonomy(). 
               */ 
              if ( isset( $this->query_vars['taxonomy'] ) && $taxonomy === $this->query_vars['taxonomy'] ) { 
                  unset( $this->query_vars['taxonomy'], $this->query_vars['term'] ); 
              } 
          } 
      } 
 
      // Limit publicly queried post_types to those that are publicly_queryable 
      if ( isset( $this->query_vars['post_type']) ) { 
          $queryable_post_types = get_post_types( array('publicly_queryable' => true) ); 
          if ( ! is_array( $this->query_vars['post_type'] ) ) { 
              if ( ! in_array( $this->query_vars['post_type'], $queryable_post_types ) ) 
                  unset( $this->query_vars['post_type'] ); 
          } else { 
              $this->query_vars['post_type'] = array_intersect( $this->query_vars['post_type'], $queryable_post_types ); 
          } 
      } 
 
      // Resolve conflicts between posts with numeric slugs and date archive queries. 
      $this->query_vars = wp_resolve_numeric_slug_conflicts( $this->query_vars ); 
 
      foreach ( (array) $this->private_query_vars as $var) { 
          if ( isset($this->extra_query_vars[$var]) ) 
              $this->query_vars[$var] = $this->extra_query_vars[$var]; 
      } 
 
      if ( isset($error) ) 
          $this->query_vars['error'] = $error; 
 
      /** 
       * Filters the array of parsed query variables. 
       * 
       * @since 2.1.0 
       * 
       * @param array $query_vars The array of requested query variables. 
       */ 
      $this->query_vars = apply_filters( 'request', $this->query_vars ); 
 
      /** 
       * Fires once all query variables for the current request have been parsed. 
       * 
       * @since 2.1.0 
       * 
       * @param WP &$this Current WordPress environment instance (passed by reference). 
       */ 
      do_action_ref_array( 'parse_request', array( &$this ) ); 
  } 
 
  /** 
   * Sends additional HTTP headers for caching, content type, etc. 
   * 
   * Sets the Content-Type header. Sets the 'error' status (if passed) and optionally exits. 
   * If showing a feed, it will also send Last-Modified, ETag, and 304 status if needed. 
   * 
   * @since 2.0.0 
   * @since 4.4.0 `X-Pingback` header is added conditionally after posts have been queried in handle_404(). 
   * @access public 
   */ 
  public function send_headers() { 
      $headers = array(); 
      $status = null; 
      $exit_required = false; 
 
      if ( is_user_logged_in() ) 
          $headers = array_merge($headers, wp_get_nocache_headers()); 
      if ( ! empty( $this->query_vars['error'] ) ) { 
          $status = (int) $this->query_vars['error']; 
          if ( 404 === $status ) { 
              if ( ! is_user_logged_in() ) 
                  $headers = array_merge($headers, wp_get_nocache_headers()); 
              $headers['Content-Type'] = get_option('html_type') . '; charset=' . get_option('blog_charset'); 
          } elseif ( in_array( $status, array( 403, 500, 502, 503 ) ) ) { 
              $exit_required = true; 
          } 
      } elseif ( empty( $this->query_vars['feed'] ) ) { 
          $headers['Content-Type'] = get_option('html_type') . '; charset=' . get_option('blog_charset'); 
      } else { 
          // Set the correct content type for feeds 
          $type = $this->query_vars['feed']; 
          if ( 'feed' == $this->query_vars['feed'] ) { 
              $type = get_default_feed(); 
          } 
          $headers['Content-Type'] = feed_content_type( $type ) . '; charset=' . get_option( 'blog_charset' ); 
 
          // We're showing a feed, so WP is indeed the only thing that last changed. 
          if ( ! empty( $this->query_vars['withcomments'] ) 
               || false !== strpos( $this->query_vars['feed'], 'comments-' ) 
               || ( empty( $this->query_vars['withoutcomments'] ) 
                    && ( ! empty( $this->query_vars['p'] ) 
                         || ! empty( $this->query_vars['name'] ) 
                         || ! empty( $this->query_vars['page_id'] ) 
                         || ! empty( $this->query_vars['pagename'] ) 
                         || ! empty( $this->query_vars['attachment'] ) 
                         || ! empty( $this->query_vars['attachment_id'] ) 
 ) 
 ) 
 ) { 
              $wp_last_modified = mysql2date( 'D, d M Y H:i:s', get_lastcommentmodified( 'GMT' ), false ); 
          } else { 
              $wp_last_modified = mysql2date( 'D, d M Y H:i:s', get_lastpostmodified( 'GMT' ), false ); 
          } 
 
          if ( ! $wp_last_modified ) { 
              $wp_last_modified = date( 'D, d M Y H:i:s' ); 
          } 
 
          $wp_last_modified .= ' GMT'; 
 
          $wp_etag = '"' . md5($wp_last_modified) . '"'; 
          $headers['Last-Modified'] = $wp_last_modified; 
          $headers['ETag'] = $wp_etag; 
 
          // Support for Conditional GET 
          if (isset($_SERVER['HTTP_IF_NONE_MATCH'])) 
              $client_etag = wp_unslash( $_SERVER['HTTP_IF_NONE_MATCH'] ); 
          else $client_etag = false; 
 
          $client_last_modified = empty($_SERVER['HTTP_IF_MODIFIED_SINCE']) ? '' : trim($_SERVER['HTTP_IF_MODIFIED_SINCE']); 
          // If string is empty, return 0. If not, attempt to parse into a timestamp 
          $client_modified_timestamp = $client_last_modified ? strtotime($client_last_modified) : 0; 
 
          // Make a timestamp for our most recent modification... 
          $wp_modified_timestamp = strtotime($wp_last_modified); 
 
          if ( ($client_last_modified && $client_etag) ? 
                   (($client_modified_timestamp >= $wp_modified_timestamp) && ($client_etag == $wp_etag)) : 
                   (($client_modified_timestamp >= $wp_modified_timestamp) || ($client_etag == $wp_etag)) ) { 
              $status = 304; 
              $exit_required = true; 
          } 
      } 
 
      /** 
       * Filters the HTTP headers before they're sent to the browser. 
       * 
       * @since 2.8.0 
       * 
       * @param array $headers The list of headers to be sent. 
       * @param WP    $this    Current WordPress environment instance. 
       */ 
      $headers = apply_filters( 'wp_headers', $headers, $this ); 
 
      if ( ! empty( $status ) ) 
          status_header( $status ); 
 
      // If Last-Modified is set to false, it should not be sent (no-cache situation). 
      if ( isset( $headers['Last-Modified'] ) && false === $headers['Last-Modified'] ) { 
          unset( $headers['Last-Modified'] ); 
 
          // In PHP 5.3+, make sure we are not sending a Last-Modified header. 
          if ( function_exists( 'header_remove' ) ) { 
              @header_remove( 'Last-Modified' ); 
          } else { 
              // In PHP 5.2, send an empty Last-Modified header, but only as a 
              // last resort to override a header already sent. #WP23021 
              foreach ( headers_list() as $header ) { 
                  if ( 0 === stripos( $header, 'Last-Modified' ) ) { 
                      $headers['Last-Modified'] = ''; 
                      break; 
                  } 
              } 
          } 
      } 
 
      foreach ( (array) $headers as $name => $field_value ) 
          @header("{$name}: {$field_value}"); 
 
      if ( $exit_required ) 
          exit(); 
 
      /** 
       * Fires once the requested HTTP headers for caching, content type, etc. have been sent. 
       * 
       * @since 2.1.0 
       * 
       * @param WP &$this Current WordPress environment instance (passed by reference). 
       */ 
      do_action_ref_array( 'send_headers', array( &$this ) ); 
  } 
 
  /** 
   * Sets the query string property based off of the query variable property. 
   * 
   * The {@see 'query_string'} filter is deprecated, but still works. Plugins should 
   * use the {@see 'request'} filter instead. 
   * 
   * @since 2.0.0 
   * @access public 
   */ 
  public function build_query_string() { 
      $this->query_string = ''; 
      foreach ( (array) array_keys($this->query_vars) as $wpvar) { 
          if ( '' != $this->query_vars[$wpvar] ) { 
              $this->query_string .= (strlen($this->query_string) < 1) ? '' : '&'; 
              if ( !is_scalar($this->query_vars[$wpvar]) ) // Discard non-scalars. 
                  continue; 
              $this->query_string .= $wpvar . '=' . rawurlencode($this->query_vars[$wpvar]); 
          } 
      } 
 
      if ( has_filter( 'query_string' ) ) {  // Don't bother filtering and parsing if no plugins are hooked in. 
          /** 
           * Filters the query string before parsing. 
           * 
           * @since 1.5.0 
           * @deprecated 2.1.0 Use 'query_vars' or 'request' filters instead. 
           * 
           * @param string $query_string The query string to modify. 
           */ 
          $this->query_string = apply_filters( 'query_string', $this->query_string ); 
          parse_str($this->query_string, $this->query_vars); 
      } 
  } 
 
  /** 
   * Set up the WordPress Globals. 
   * 
   * The query_vars property will be extracted to the GLOBALS. So care should 
   * be taken when naming global variables that might interfere with the 
   * WordPress environment. 
   * 
   * @since 2.0.0 
   * @access public 
   * 
   * @global WP_Query     $wp_query 
   * @global string       $query_string Query string for the loop. 
   * @global array        $posts The found posts. 
   * @global WP_Post|null $post The current post, if available. 
   * @global string       $request The SQL statement for the request. 
   * @global int          $more Only set, if single page or post. 
   * @global int          $single If single page or post. Only set, if single page or post. 
   * @global WP_User      $authordata Only set, if author archive. 
   */ 
  public function register_globals() { 
      global $wp_query; 
 
      // Extract updated query vars back into global namespace. 
      foreach ( (array) $wp_query->query_vars as $key => $value ) { 
          $GLOBALS[ $key ] = $value; 
      } 
 
      $GLOBALS['query_string'] = $this->query_string; 
      $GLOBALS['posts'] = & $wp_query->posts; 
      $GLOBALS['post'] = isset( $wp_query->post ) ? $wp_query->post : null; 
      $GLOBALS['request'] = $wp_query->request; 
 
      if ( $wp_query->is_single() || $wp_query->is_page() ) { 
          $GLOBALS['more'] = 1; 
          $GLOBALS['single'] = 1; 
      } 
 
      if ( $wp_query->is_author() && isset( $wp_query->post ) ) 
          $GLOBALS['authordata'] = get_userdata( $wp_query->post->post_author ); 
  } 
 
  /** 
   * Set up the current user. 
   * 
   * @since 2.0.0 
   * @access public 
   */ 
  public function init() { 
      wp_get_current_user(); 
  } 
 
  /** 
   * Set up the Loop based on the query variables. 
   * 
   * @since 2.0.0 
   * @access public 
   * 
   * @global WP_Query $wp_the_query 
   */ 
  public function query_posts() { 
      global $wp_the_query; 
      $this->build_query_string(); 
      $wp_the_query->query($this->query_vars); 
   } 
 
   /** 
   * Set the Headers for 404, if nothing is found for requested URL. 
   * 
   * Issue a 404 if a request doesn't match any posts and doesn't match 
   * any object (e.g. an existing-but-empty category, tag, author) and a 404 was not already 
   * issued, and if the request was not a search or the homepage. 
   * 
   * Otherwise, issue a 200. 
   * 
   * This sets headers after posts have been queried. handle_404() really means "handle status." 
   * By inspecting the result of querying posts, seemingly successful requests can be switched to 
   * a 404 so that canonical redirection logic can kick in. 
   * 
   * @since 2.0.0 
   * @access public 
   * 
   * @global WP_Query $wp_query 
    */ 
  public function handle_404() { 
      global $wp_query; 
 
      /** 
       * Filters whether to short-circuit default header status handling. 
       * 
       * Returning a non-false value from the filter will short-circuit the handling 
       * and return early. 
       * 
       * @since 4.5.0 
       * 
       * @param bool     $preempt  Whether to short-circuit default header status handling. Default false. 
       * @param WP_Query $wp_query WordPress Query object. 
       */ 
      if ( false !== apply_filters( 'pre_handle_404', false, $wp_query ) ) { 
          return; 
      } 
 
      // If we've already issued a 404, bail. 
      if ( is_404() ) 
          return; 
 
      // Never 404 for the admin, robots, or if we found posts. 
      if ( is_admin() || is_robots() || $wp_query->posts ) { 
 
          $success = true; 
          if ( is_singular() ) { 
              $p = false; 
 
              if ( $wp_query->post instanceof WP_Post ) { 
                  $p = clone $wp_query->post; 
              } 
 
              // Only set X-Pingback for single posts that allow pings. 
              if ( $p && pings_open( $p ) ) { 
                  @header( 'X-Pingback: ' . get_bloginfo( 'pingback_url', 'display' ) ); 
              } 
 
              // check for paged content that exceeds the max number of pages 
              $next = '<!--nextpage-->'; 
              if ( $p && false !== strpos( $p->post_content, $next ) && ! empty( $this->query_vars['page'] ) ) { 
                  $page = trim( $this->query_vars['page'], '/' ); 
                  $success = (int) $page <= ( substr_count( $p->post_content, $next ) + 1 ); 
              } 
          } 
 
          if ( $success ) { 
              status_header( 200 ); 
              return; 
          } 
      } 
 
      // We will 404 for paged queries, as no posts were found. 
      if ( ! is_paged() ) { 
 
          // Don't 404 for authors without posts as long as they matched an author on this site. 
          $author = get_query_var( 'author' ); 
          if ( is_author() && is_numeric( $author ) && $author > 0 && is_user_member_of_blog( $author ) ) { 
              status_header( 200 ); 
              return; 
          } 
 
          // Don't 404 for these queries if they matched an object. 
          if ( ( is_tag() || is_category() || is_tax() || is_post_type_archive() ) && get_queried_object() ) { 
              status_header( 200 ); 
              return; 
          } 
 
          // Don't 404 for these queries either. 
          if ( is_home() || is_search() || is_feed() ) { 
              status_header( 200 ); 
              return; 
          } 
      } 
 
      // Guess it's time to 404. 
      $wp_query->set_404(); 
      status_header( 404 ); 
      nocache_headers(); 
  } 
 
  /** 
   * Sets up all of the variables required by the WordPress environment. 
   * 
   * The action {@see 'wp'} has one parameter that references the WP object. It 
   * allows for accessing the properties and methods to further manipulate the 
   * object. 
   * 
   * @since 2.0.0 
   * @access public 
   * 
   * @param string|array $query_args Passed to parse_request(). 
   */ 
  public function main($query_args = '') { 
      $this->init(); 
      $this->parse_request($query_args); 
      $this->send_headers(); 
      $this->query_posts(); 
      $this->handle_404(); 
      $this->register_globals(); 
 
      /** 
       * Fires once the WordPress environment has been set up. 
       * 
       * @since 2.1.0 
       * 
       * @param WP &$this Current WordPress environment instance (passed by reference). 
       */ 
      do_action_ref_array( 'wp', array( &$this ) ); 
  } 
}