root/trunk/wp-includes/classes.php

<?php
/**
 * Holds Most of the WordPress classes.
 *
 * Some of the other classes are contained in other files. For example, the
 * WordPress cache is in cache.php and the WordPress roles API is in
 * capabilities.php. The third party libraries are contained in their own
 * separate files.
 *
 * @package WordPress
 */

/**
 * 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
     */
    var $public_query_vars = array('m', 'p', 'posts', 'w', 'cat', 'withcomments', 'withoutcomments', 's', 'search', 'exact', 'sentence', 'debug', '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', 'comments_popup', 'attachment', 'attachment_id', 'subpost', 'subpost_id', 'preview', 'robots', 'taxonomy', 'term', 'cpage');

    /**
     * Private query variables.
     *
     * Long list of private query variables.
     *
     * @since 2.0.0
     * @var array
     */
    var $private_query_vars = array('offset', 'posts_per_page', 'posts_per_archive_page', 'what_to_show', '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');

    /**
     * Extra query variables set by the user.
     *
     * @since 2.1.0
     * @var array
     */
    var $extra_query_vars = array();

    /**
     * Query variables for setting up the WordPress Query Loop.
     *
     * @since 2.0.0
     * @var array
     */
    var $query_vars;

    /**
     * String parsed to set the query variables.
     *
     * @since 2.0.0
     * @var string
     */
    var $query_string;

    /**
     * Permalink or requested URI.
     *
     * @since 2.0.0
     * @var string
     */
    var $request;

    /**
     * Rewrite rule the request matched.
     *
     * @since 2.0.0
     * @var string
     */
    var $matched_rule;

    /**
     * Rewrite query the request matched.
     *
     * @since 2.0.0
     * @var string
     */
    var $matched_query;

    /**
     * Whether already did the permalink.
     *
     * @since 2.0.0
     * @var bool
     */
    var $did_permalink = false;

    /**
     * Add name to list of public query variables.
     *
     * @since 2.1.0
     *
     * @param string $qv Query variable name.
     */
    function add_query_var($qv) {
        if ( !in_array($qv, $this->public_query_vars) )
            $this->public_query_vars[] = $qv;
    }

    /**
     * Set the value of a query variable.
     *
     * @since 2.3.0
     *
     * @param string $key Query variable name.
     * @param mixed $value Query variable value.
     */
    function set_query_var($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
     *
     * @param array|string $extra_query_vars Set the extra query variables.
     */
    function parse_request($extra_query_vars = '') {
        global $wp_rewrite;

        $this->query_vars = array();
        $taxonomy_query_vars = array();

        if ( is_array($extra_query_vars) )
            $this->extra_query_vars = & $extra_query_vars;
        else if (! empty($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;

            if ( isset($_SERVER['PATH_INFO']) )
                $pathinfo = $_SERVER['PATH_INFO'];
            else
                $pathinfo = '';
            $pathinfo_array = explode('?', $pathinfo);
            $pathinfo = str_replace("%", "%25", $pathinfo_array[0]);
            $req_uri = $_SERVER['REQUEST_URI'];
            $req_uri_array = explode('?', $req_uri);
            $req_uri = $req_uri_array[0];
            $self = $_SERVER['PHP_SELF'];
            $home_path = parse_url(get_option('home'));
            if ( isset($home_path['path']) )
                $home_path = $home_path['path'];
            else
                $home_path = '';
            $home_path = trim($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, '', rawurldecode($req_uri));
            $req_uri = trim($req_uri, '/');
            $req_uri = preg_replace("|^$home_path|", '', $req_uri);
            $req_uri = trim($req_uri, '/');
            $pathinfo = trim($pathinfo, '/');
            $pathinfo = preg_replace("|^$home_path|", '', $pathinfo);
            $pathinfo = trim($pathinfo, '/');
            $self = trim($self, '/');
            $self = preg_replace("|^$home_path|", '', $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) ) {
                $request = $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 = '';
                $request = $req_uri;
            }

            $this->request = $request;

            // Look for matches.
            $request_match = $request;
            foreach ( (array) $rewrite as $match => $query) {
                // Don't try to match against AtomPub calls
                if ( $req_uri == 'wp-app.php' )
                    break;

                // If the requesting file is the anchor of the match, prepend it
                // to the path info.
                if ((! empty($req_uri)) && (strpos($match, $req_uri) === 0) && ($req_uri != $request)) {
                    $request_match = $req_uri . '/' . $request;
                }

                if (preg_match("!^$match!", $request_match, $matches) ||
                    preg_match("!^$match!", urldecode($request_match), $matches)) {
                    // Got a match.
                    $this->matched_rule = $match;

                    // Trim the query of everything up to the '?'.
                    $query = preg_replace("!^.+\?!", '', $query);

                    // Substitute the substring matches into the query.
                    eval("@\$query = \"" . addslashes($query) . "\";");

                    $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 (isset($_GET['error']))
                        unset($_GET['error']);

                    if (isset($error))
                        unset($error);

                    break;
                }
            }

            // If req_uri is empty or if it is a request for ourself, unset error.
            if (empty($request) || $req_uri == $self || strpos($_SERVER['PHP_SELF'], 'wp-admin/') !== false) {
                if (isset($_GET['error']))
                    unset($_GET['error']);

                if (isset($error))
                    unset($error);

                if (isset($perma_query_vars) && strpos($_SERVER['PHP_SELF'], 'wp-admin/') !== false)
                    unset($perma_query_vars);

                $this->did_permalink = false;
            }
        }

        $this->public_query_vars = apply_filters('query_vars', $this->public_query_vars);

        foreach ( $GLOBALS['wp_taxonomies'] as $taxonomy => $t )
            if ( isset($t->query_var) )
                $taxonomy_query_vars[$t->query_var] = $taxonomy;

        for ($i=0; $i<count($this->public_query_vars); $i += 1) {
            $wpvar = $this->public_query_vars[$i];
            if (isset($this->extra_query_vars[$wpvar]))
                $this->query_vars[$wpvar] = $this->extra_query_vars[$wpvar];
            elseif (isset($GLOBALS[$wpvar]))
                $this->query_vars[$wpvar] = $GLOBALS[$wpvar];
            elseif (!empty($_POST[$wpvar]))
                $this->query_vars[$wpvar] = $_POST[$wpvar];
            elseif (!empty($_GET[$wpvar]))
                $this->query_vars[$wpvar] = $_GET[$wpvar];
            elseif (!empty($perma_query_vars[$wpvar]))
                $this->query_vars[$wpvar] = $perma_query_vars[$wpvar];

            if ( !empty( $this->query_vars[$wpvar] ) ) {
                $this->query_vars[$wpvar] = (string) $this->query_vars[$wpvar];
                if ( in_array( $wpvar, $taxonomy_query_vars ) ) {
                    $this->query_vars['taxonomy'] = $taxonomy_query_vars[$wpvar];
                    $this->query_vars['term'] = $this->query_vars[$wpvar];
                }
            }
        }

        foreach ( (array) $this->private_query_vars as $var) {
            if (isset($this->extra_query_vars[$var]))
                $this->query_vars[$var] = $this->extra_query_vars[$var];
            elseif (isset($GLOBALS[$var]) && '' != $GLOBALS[$var])
                $this->query_vars[$var] = $GLOBALS[$var];
        }

        if ( isset($error) )
            $this->query_vars['error'] = $error;

        $this->query_vars = apply_filters('request', $this->query_vars);

        do_action_ref_array('parse_request', array(&$this));
    }

    /**
     * Send additional HTTP headers for caching, content type, etc.
     *
     * Sets the X-Pingback header, 404 status (if 404), Content-type. If showing
     * a feed, it will also send last-modified, etag, and 304 status if needed.
     *
     * @since 2.0.0
     */
    function send_headers() {
        @header('X-Pingback: '. get_bloginfo('pingback_url'));
        if ( is_user_logged_in() )
            nocache_headers();
        if ( !empty($this->query_vars['error']) && '404' == $this->query_vars['error'] ) {
            status_header( 404 );
            if ( !is_user_logged_in() )
                nocache_headers();
            @header('Content-Type: ' . get_option('html_type') . '; charset=' . get_option('blog_charset'));
        } else if ( empty($this->query_vars['feed']) ) {
            @header('Content-Type: ' . get_option('html_type') . '; charset=' . get_option('blog_charset'));
        } else {
            // We're showing a feed, so WP is indeed the only thing that last changed
            if ( !empty($this->query_vars['withcomments'])
                || ( empty($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'), 0).' GMT';
            else
                $wp_last_modified = mysql2date('D, d M Y H:i:s', get_lastpostmodified('GMT'), 0).' GMT';
            $wp_etag = '"' . md5($wp_last_modified) . '"';
            @header("Last-Modified: $wp_last_modified");
            @header("ETag: $wp_etag");

            // Support for Conditional GET
            if (isset($_SERVER['HTTP_IF_NONE_MATCH']))
                $client_etag = stripslashes(stripslashes($_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_header( 304 );
                exit;
            }
        }

        do_action_ref_array('send_headers', array(&$this));
    }

    /**
     * Sets the query string property based off of the query variable property.
     *
     * The 'query_string' filter is deprecated, but still works. Plugins should
     * use the 'request' filter instead.
     *
     * @since 2.0.0
     */
    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]);
            }
        }

        // query_string filter deprecated.  Use request filter instead.
        if ( has_filter('query_string') ) {  // Don't bother filtering and parsing if no plugins are hooked in.
            $this->query_string = apply_filters('query_string', $this->query_string);
            parse_str($this->query_string, $this->query_vars);
        }
    }

    /**
     * Setup 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.
     *
     * @global string $query_string Query string for the loop.
     * @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.
     *
     * @since 2.0.0
     */
    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'] = & $wp_query->post;
        $GLOBALS['request'] = & $wp_query->request;

        if ( is_single() || is_page() ) {
            $GLOBALS['more'] = 1;
            $GLOBALS['single'] = 1;
        }
    }

    /**
     * Setup the current user.
     *
     * @since 2.0.0
     */
    function init() {
        wp_get_current_user();
    }

    /**
     * Setup the Loop based on the query variables.
     *
     * @uses WP::$query_vars
     * @since 2.0.0
     */
    function query_posts() {
        global $wp_the_query;
        $this->build_query_string();
        $wp_the_query->query($this->query_vars);
     }

     /**
      * Set the Headers for 404, if permalink is not found.
     *
     * Issue a 404 if a permalink request doesn't match any posts.  Don't issue
     * a 404 if one was already issued, if the request was a search, or if the
     * request was a regular query string request rather than a permalink
     * request. Issues a 200, if not 404.
     *
     * @since 2.0.0
      */
    function handle_404() {
        global $wp_query;

        if ( (0 == count($wp_query->posts)) && !is_404() && !is_search() && ( $this->did_permalink || (!empty($_SERVER['QUERY_STRING']) && (false === strpos($_SERVER['REQUEST_URI'], '?'))) ) ) {
            // Don't 404 for these queries if they matched an object.
            if ( ( is_tag() || is_category() || is_author() ) && $wp_query->get_queried_object() ) {
                if ( !is_404() )
                    status_header( 200 );
                return;
            }
            $wp_query->set_404();
            status_header( 404 );
            nocache_headers();
        } elseif ( !is_404() ) {
            status_header( 200 );
        }
    }

    /**
     * Sets up all of the variables required by the WordPress environment.
     *
     * The action '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
     *
     * @param string|array $query_args Passed to {@link parse_request()}
     */
    function main($query_args = '') {
        $this->init();
        $this->parse_request($query_args);
        $this->send_headers();
        $this->query_posts();
        $this->handle_404();
        $this->register_globals();
        do_action_ref_array('wp', array(&$this));
    }

    /**
     * PHP4 Constructor - Does nothing.
     *
     * Call main() method when ready to run setup.
     *
     * @since 2.0.0
     *
     * @return WP
     */
    function WP() {
        // Empty.
    }
}

/**
 * WordPress Error class.
 *
 * Container for checking for WordPress errors and error messages. Return
 * WP_Error and use {@link is_wp_error()} to check if this class is returned.
 * Many core WordPress functions pass this class in the event of an error and
 * if not handled properly will result in code errors.
 *
 * @package WordPress
 * @since 2.1.0
 */
class WP_Error {
    /**
     * Stores the list of errors.
     *<