ms_load_current_site_and_network

The timeline below displays how wordpress function ms_load_current_site_and_network has changed across different WordPress versions. If a version is not listed, refer to the next available version below.

WordPress Version: 6.3

/**
 * Identifies the network and site of a requested domain and path and populates the
 * corresponding network and site global objects as part of the multisite bootstrap process.
 *
 * Prior to 4.6.0, this was a procedural block in `ms-settings.php`. It was wrapped into
 * a function to facilitate unit tests. It should not be used outside of core.
 *
 * Usually, it's easier to query the site first, which then declares its network.
 * In limited situations, we either can or must find the network first.
 *
 * If a network and site are found, a `true` response will be returned so that the
 * request can continue.
 *
 * If neither a network or site is found, `false` or a URL string will be returned
 * so that either an error can be shown or a redirect can occur.
 *
 * @since 4.6.0
 * @access private
 *
 * @global WP_Network $current_site The current network.
 * @global WP_Site    $current_blog The current site.
 *
 * @param string $domain    The requested domain.
 * @param string $path      The requested path.
 * @param bool   $subdomain Optional. Whether a subdomain (true) or subdirectory (false) configuration.
 *                          Default false.
 * @return bool|string True if bootstrap successfully populated `$current_blog` and `$current_site`.
 *                     False if bootstrap could not be properly completed.
 *                     Redirect URL if parts exist, but the request as a whole can not be fulfilled.
 */
function ms_load_current_site_and_network($domain, $path, $subdomain = false)
{
    global $current_site, $current_blog;
    // If the network is defined in wp-config.php, we can simply use that.
    if (defined('DOMAIN_CURRENT_SITE') && defined('PATH_CURRENT_SITE')) {
        $current_site = new stdClass();
        $current_site->id = defined('SITE_ID_CURRENT_SITE') ? SITE_ID_CURRENT_SITE : 1;
        $current_site->domain = DOMAIN_CURRENT_SITE;
        $current_site->path = PATH_CURRENT_SITE;
        if (defined('BLOG_ID_CURRENT_SITE')) {
            $current_site->blog_id = BLOG_ID_CURRENT_SITE;
        } elseif (defined('BLOGID_CURRENT_SITE')) {
            // Deprecated.
            $current_site->blog_id = BLOGID_CURRENT_SITE;
        }
        if (0 === strcasecmp($current_site->domain, $domain) && 0 === strcasecmp($current_site->path, $path)) {
            $current_blog = get_site_by_path($domain, $path);
        } elseif ('/' !== $current_site->path && 0 === strcasecmp($current_site->domain, $domain) && 0 === stripos($path, $current_site->path)) {
            /*
             * If the current network has a path and also matches the domain and path of the request,
             * we need to look for a site using the first path segment following the network's path.
             */
            $current_blog = get_site_by_path($domain, $path, 1 + count(explode('/', trim($current_site->path, '/'))));
        } else {
            // Otherwise, use the first path segment (as usual).
            $current_blog = get_site_by_path($domain, $path, 1);
        }
    } elseif (!$subdomain) {
        /*
         * A "subdomain" installation can be re-interpreted to mean "can support any domain".
         * If we're not dealing with one of these installations, then the important part is determining
         * the network first, because we need the network's path to identify any sites.
         */
        $current_site = wp_cache_get('current_network', 'site-options');
        if (!$current_site) {
            // Are there even two networks installed?
            $networks = get_networks(array('number' => 2));
            if (count($networks) === 1) {
                $current_site = array_shift($networks);
                wp_cache_add('current_network', $current_site, 'site-options');
            } elseif (empty($networks)) {
                // A network not found hook should fire here.
                return false;
            }
        }
        if (empty($current_site)) {
            $current_site = WP_Network::get_by_path($domain, $path, 1);
        }
        if (empty($current_site)) {
            /**
             * Fires when a network cannot be found based on the requested domain and path.
             *
             * At the time of this action, the only recourse is to redirect somewhere
             * and exit. If you want to declare a particular network, do so earlier.
             *
             * @since 4.4.0
             *
             * @param string $domain       The domain used to search for a network.
             * @param string $path         The path used to search for a path.
             */
            do_action('ms_network_not_found', $domain, $path);
            return false;
        } elseif ($path === $current_site->path) {
            $current_blog = get_site_by_path($domain, $path);
        } else {
            // Search the network path + one more path segment (on top of the network path).
            $current_blog = get_site_by_path($domain, $path, substr_count($current_site->path, '/'));
        }
    } else {
        // Find the site by the domain and at most the first path segment.
        $current_blog = get_site_by_path($domain, $path, 1);
        if ($current_blog) {
            $current_site = WP_Network::get_instance($current_blog->site_id ? $current_blog->site_id : 1);
        } else {
            // If you don't have a site with the same domain/path as a network, you're pretty screwed, but:
            $current_site = WP_Network::get_by_path($domain, $path, 1);
        }
    }
    // The network declared by the site trumps any constants.
    if ($current_blog && $current_blog->site_id != $current_site->id) {
        $current_site = WP_Network::get_instance($current_blog->site_id);
    }
    // No network has been found, bail.
    if (empty($current_site)) {
        /** This action is documented in wp-includes/ms-settings.php */
        do_action('ms_network_not_found', $domain, $path);
        return false;
    }
    // During activation of a new subdomain, the requested site does not yet exist.
    if (empty($current_blog) && wp_installing()) {
        $current_blog = new stdClass();
        $current_blog->blog_id = 1;
        $blog_id = 1;
        $current_blog->public = 1;
    }
    // No site has been found, bail.
    if (empty($current_blog)) {
        // We're going to redirect to the network URL, with some possible modifications.
        $scheme = is_ssl() ? 'https' : 'http';
        $destination = "{$scheme}://{$current_site->domain}{$current_site->path}";
        /**
         * Fires when a network can be determined but a site cannot.
         *
         * At the time of this action, the only recourse is to redirect somewhere
         * and exit. If you want to declare a particular site, do so earlier.
         *
         * @since 3.9.0
         *
         * @param WP_Network $current_site The network that had been determined.
         * @param string     $domain       The domain used to search for a site.
         * @param string     $path         The path used to search for a site.
         */
        do_action('ms_site_not_found', $current_site, $domain, $path);
        if ($subdomain && !defined('NOBLOGREDIRECT')) {
            // For a "subdomain" installation, redirect to the signup form specifically.
            $destination .= 'wp-signup.php?new=' . str_replace('.' . $current_site->domain, '', $domain);
        } elseif ($subdomain) {
            /*
             * For a "subdomain" installation, the NOBLOGREDIRECT constant
             * can be used to avoid a redirect to the signup form.
             * Using the ms_site_not_found action is preferred to the constant.
             */
            if ('%siteurl%' !== NOBLOGREDIRECT) {
                $destination = NOBLOGREDIRECT;
            }
        } elseif (0 === strcasecmp($current_site->domain, $domain)) {
            /*
             * If the domain we were searching for matches the network's domain,
             * it's no use redirecting back to ourselves -- it'll cause a loop.
             * As we couldn't find a site, we're simply not installed.
             */
            return false;
        }
        return $destination;
    }
    // Figure out the current network's main site.
    if (empty($current_site->blog_id)) {
        $current_site->blog_id = get_main_site_id($current_site->id);
    }
    return true;
}

WordPress Version: 5.6

/**
 * Identifies the network and site of a requested domain and path and populates the
 * corresponding network and site global objects as part of the multisite bootstrap process.
 *
 * Prior to 4.6.0, this was a procedural block in `ms-settings.php`. It was wrapped into
 * a function to facilitate unit tests. It should not be used outside of core.
 *
 * Usually, it's easier to query the site first, which then declares its network.
 * In limited situations, we either can or must find the network first.
 *
 * If a network and site are found, a `true` response will be returned so that the
 * request can continue.
 *
 * If neither a network or site is found, `false` or a URL string will be returned
 * so that either an error can be shown or a redirect can occur.
 *
 * @since 4.6.0
 * @access private
 *
 * @global WP_Network $current_site The current network.
 * @global WP_Site    $current_blog The current site.
 *
 * @param string $domain    The requested domain.
 * @param string $path      The requested path.
 * @param bool   $subdomain Optional. Whether a subdomain (true) or subdirectory (false) configuration.
 *                          Default false.
 * @return bool|string True if bootstrap successfully populated `$current_blog` and `$current_site`.
 *                     False if bootstrap could not be properly completed.
 *                     Redirect URL if parts exist, but the request as a whole can not be fulfilled.
 */
function ms_load_current_site_and_network($domain, $path, $subdomain = false)
{
    global $current_site, $current_blog;
    // If the network is defined in wp-config.php, we can simply use that.
    if (defined('DOMAIN_CURRENT_SITE') && defined('PATH_CURRENT_SITE')) {
        $current_site = new stdClass();
        $current_site->id = defined('SITE_ID_CURRENT_SITE') ? SITE_ID_CURRENT_SITE : 1;
        $current_site->domain = DOMAIN_CURRENT_SITE;
        $current_site->path = PATH_CURRENT_SITE;
        if (defined('BLOG_ID_CURRENT_SITE')) {
            $current_site->blog_id = BLOG_ID_CURRENT_SITE;
        } elseif (defined('BLOGID_CURRENT_SITE')) {
            // Deprecated.
            $current_site->blog_id = BLOGID_CURRENT_SITE;
        }
        if (0 === strcasecmp($current_site->domain, $domain) && 0 === strcasecmp($current_site->path, $path)) {
            $current_blog = get_site_by_path($domain, $path);
        } elseif ('/' !== $current_site->path && 0 === strcasecmp($current_site->domain, $domain) && 0 === stripos($path, $current_site->path)) {
            // If the current network has a path and also matches the domain and path of the request,
            // we need to look for a site using the first path segment following the network's path.
            $current_blog = get_site_by_path($domain, $path, 1 + count(explode('/', trim($current_site->path, '/'))));
        } else {
            // Otherwise, use the first path segment (as usual).
            $current_blog = get_site_by_path($domain, $path, 1);
        }
    } elseif (!$subdomain) {
        /*
         * A "subdomain" installation can be re-interpreted to mean "can support any domain".
         * If we're not dealing with one of these installations, then the important part is determining
         * the network first, because we need the network's path to identify any sites.
         */
        $current_site = wp_cache_get('current_network', 'site-options');
        if (!$current_site) {
            // Are there even two networks installed?
            $networks = get_networks(array('number' => 2));
            if (count($networks) === 1) {
                $current_site = array_shift($networks);
                wp_cache_add('current_network', $current_site, 'site-options');
            } elseif (empty($networks)) {
                // A network not found hook should fire here.
                return false;
            }
        }
        if (empty($current_site)) {
            $current_site = WP_Network::get_by_path($domain, $path, 1);
        }
        if (empty($current_site)) {
            /**
             * Fires when a network cannot be found based on the requested domain and path.
             *
             * At the time of this action, the only recourse is to redirect somewhere
             * and exit. If you want to declare a particular network, do so earlier.
             *
             * @since 4.4.0
             *
             * @param string $domain       The domain used to search for a network.
             * @param string $path         The path used to search for a path.
             */
            do_action('ms_network_not_found', $domain, $path);
            return false;
        } elseif ($path === $current_site->path) {
            $current_blog = get_site_by_path($domain, $path);
        } else {
            // Search the network path + one more path segment (on top of the network path).
            $current_blog = get_site_by_path($domain, $path, substr_count($current_site->path, '/'));
        }
    } else {
        // Find the site by the domain and at most the first path segment.
        $current_blog = get_site_by_path($domain, $path, 1);
        if ($current_blog) {
            $current_site = WP_Network::get_instance($current_blog->site_id ? $current_blog->site_id : 1);
        } else {
            // If you don't have a site with the same domain/path as a network, you're pretty screwed, but:
            $current_site = WP_Network::get_by_path($domain, $path, 1);
        }
    }
    // The network declared by the site trumps any constants.
    if ($current_blog && $current_blog->site_id != $current_site->id) {
        $current_site = WP_Network::get_instance($current_blog->site_id);
    }
    // No network has been found, bail.
    if (empty($current_site)) {
        /** This action is documented in wp-includes/ms-settings.php */
        do_action('ms_network_not_found', $domain, $path);
        return false;
    }
    // During activation of a new subdomain, the requested site does not yet exist.
    if (empty($current_blog) && wp_installing()) {
        $current_blog = new stdClass();
        $current_blog->blog_id = 1;
        $blog_id = 1;
        $current_blog->public = 1;
    }
    // No site has been found, bail.
    if (empty($current_blog)) {
        // We're going to redirect to the network URL, with some possible modifications.
        $scheme = is_ssl() ? 'https' : 'http';
        $destination = "{$scheme}://{$current_site->domain}{$current_site->path}";
        /**
         * Fires when a network can be determined but a site cannot.
         *
         * At the time of this action, the only recourse is to redirect somewhere
         * and exit. If you want to declare a particular site, do so earlier.
         *
         * @since 3.9.0
         *
         * @param WP_Network $current_site The network that had been determined.
         * @param string     $domain       The domain used to search for a site.
         * @param string     $path         The path used to search for a site.
         */
        do_action('ms_site_not_found', $current_site, $domain, $path);
        if ($subdomain && !defined('NOBLOGREDIRECT')) {
            // For a "subdomain" installation, redirect to the signup form specifically.
            $destination .= 'wp-signup.php?new=' . str_replace('.' . $current_site->domain, '', $domain);
        } elseif ($subdomain) {
            /*
             * For a "subdomain" installation, the NOBLOGREDIRECT constant
             * can be used to avoid a redirect to the signup form.
             * Using the ms_site_not_found action is preferred to the constant.
             */
            if ('%siteurl%' !== NOBLOGREDIRECT) {
                $destination = NOBLOGREDIRECT;
            }
        } elseif (0 === strcasecmp($current_site->domain, $domain)) {
            /*
             * If the domain we were searching for matches the network's domain,
             * it's no use redirecting back to ourselves -- it'll cause a loop.
             * As we couldn't find a site, we're simply not installed.
             */
            return false;
        }
        return $destination;
    }
    // Figure out the current network's main site.
    if (empty($current_site->blog_id)) {
        $current_site->blog_id = get_main_site_id($current_site->id);
    }
    return true;
}

WordPress Version: 5.4

/**
 * Identifies the network and site of a requested domain and path and populates the
 * corresponding network and site global objects as part of the multisite bootstrap process.
 *
 * Prior to 4.6.0, this was a procedural block in `ms-settings.php`. It was wrapped into
 * a function to facilitate unit tests. It should not be used outside of core.
 *
 * Usually, it's easier to query the site first, which then declares its network.
 * In limited situations, we either can or must find the network first.
 *
 * If a network and site are found, a `true` response will be returned so that the
 * request can continue.
 *
 * If neither a network or site is found, `false` or a URL string will be returned
 * so that either an error can be shown or a redirect can occur.
 *
 * @since 4.6.0
 * @access private
 *
 * @global WP_Network $current_site The current network.
 * @global WP_Site    $current_blog The current site.
 *
 * @param string $domain    The requested domain.
 * @param string $path      The requested path.
 * @param bool   $subdomain Optional. Whether a subdomain (true) or subdirectory (false) configuration.
 *                          Default false.
 * @return bool|string True if bootstrap successfully populated `$current_blog` and `$current_site`.
 *                     False if bootstrap could not be properly completed.
 *                     Redirect URL if parts exist, but the request as a whole can not be fulfilled.
 */
function ms_load_current_site_and_network($domain, $path, $subdomain = false)
{
    global $current_site, $current_blog;
    // If the network is defined in wp-config.php, we can simply use that.
    if (defined('DOMAIN_CURRENT_SITE') && defined('PATH_CURRENT_SITE')) {
        $current_site = new stdClass();
        $current_site->id = defined('SITE_ID_CURRENT_SITE') ? SITE_ID_CURRENT_SITE : 1;
        $current_site->domain = DOMAIN_CURRENT_SITE;
        $current_site->path = PATH_CURRENT_SITE;
        if (defined('BLOG_ID_CURRENT_SITE')) {
            $current_site->blog_id = BLOG_ID_CURRENT_SITE;
        } elseif (defined('BLOGID_CURRENT_SITE')) {
            // Deprecated.
            $current_site->blog_id = BLOGID_CURRENT_SITE;
        }
        if (0 === strcasecmp($current_site->domain, $domain) && 0 === strcasecmp($current_site->path, $path)) {
            $current_blog = get_site_by_path($domain, $path);
        } elseif ('/' !== $current_site->path && 0 === strcasecmp($current_site->domain, $domain) && 0 === stripos($path, $current_site->path)) {
            // If the current network has a path and also matches the domain and path of the request,
            // we need to look for a site using the first path segment following the network's path.
            $current_blog = get_site_by_path($domain, $path, 1 + count(explode('/', trim($current_site->path, '/'))));
        } else {
            // Otherwise, use the first path segment (as usual).
            $current_blog = get_site_by_path($domain, $path, 1);
        }
    } elseif (!$subdomain) {
        /*
         * A "subdomain" installation can be re-interpreted to mean "can support any domain".
         * If we're not dealing with one of these installations, then the important part is determining
         * the network first, because we need the network's path to identify any sites.
         */
        $current_site = wp_cache_get('current_network', 'site-options');
        if (!$current_site) {
            // Are there even two networks installed?
            $networks = get_networks(array('number' => 2));
            if (count($networks) === 1) {
                $current_site = array_shift($networks);
                wp_cache_add('current_network', $current_site, 'site-options');
            } elseif (empty($networks)) {
                // A network not found hook should fire here.
                return false;
            }
        }
        if (empty($current_site)) {
            $current_site = WP_Network::get_by_path($domain, $path, 1);
        }
        if (empty($current_site)) {
            /**
             * Fires when a network cannot be found based on the requested domain and path.
             *
             * At the time of this action, the only recourse is to redirect somewhere
             * and exit. If you want to declare a particular network, do so earlier.
             *
             * @since 4.4.0
             *
             * @param string $domain       The domain used to search for a network.
             * @param string $path         The path used to search for a path.
             */
            do_action('ms_network_not_found', $domain, $path);
            return false;
        } elseif ($path === $current_site->path) {
            $current_blog = get_site_by_path($domain, $path);
        } else {
            // Search the network path + one more path segment (on top of the network path).
            $current_blog = get_site_by_path($domain, $path, substr_count($current_site->path, '/'));
        }
    } else {
        // Find the site by the domain and at most the first path segment.
        $current_blog = get_site_by_path($domain, $path, 1);
        if ($current_blog) {
            $current_site = WP_Network::get_instance($current_blog->site_id ? $current_blog->site_id : 1);
        } else {
            // If you don't have a site with the same domain/path as a network, you're pretty screwed, but:
            $current_site = WP_Network::get_by_path($domain, $path, 1);
        }
    }
    // The network declared by the site trumps any constants.
    if ($current_blog && $current_blog->site_id != $current_site->id) {
        $current_site = WP_Network::get_instance($current_blog->site_id);
    }
    // No network has been found, bail.
    if (empty($current_site)) {
        /** This action is documented in wp-includes/ms-settings.php */
        do_action('ms_network_not_found', $domain, $path);
        return false;
    }
    // During activation of a new subdomain, the requested site does not yet exist.
    if (empty($current_blog) && wp_installing()) {
        $current_blog = new stdClass();
        $current_blog->blog_id = 1;
        $blog_id = 1;
        $current_blog->public = 1;
    }
    // No site has been found, bail.
    if (empty($current_blog)) {
        // We're going to redirect to the network URL, with some possible modifications.
        $scheme = is_ssl() ? 'https' : 'http';
        $destination = "{$scheme}://{$current_site->domain}{$current_site->path}";
        /**
         * Fires when a network can be determined but a site cannot.
         *
         * At the time of this action, the only recourse is to redirect somewhere
         * and exit. If you want to declare a particular site, do so earlier.
         *
         * @since 3.9.0
         *
         * @param object $current_site The network that had been determined.
         * @param string $domain       The domain used to search for a site.
         * @param string $path         The path used to search for a site.
         */
        do_action('ms_site_not_found', $current_site, $domain, $path);
        if ($subdomain && !defined('NOBLOGREDIRECT')) {
            // For a "subdomain" installation, redirect to the signup form specifically.
            $destination .= 'wp-signup.php?new=' . str_replace('.' . $current_site->domain, '', $domain);
        } elseif ($subdomain) {
            /*
             * For a "subdomain" installation, the NOBLOGREDIRECT constant
             * can be used to avoid a redirect to the signup form.
             * Using the ms_site_not_found action is preferred to the constant.
             */
            if ('%siteurl%' !== NOBLOGREDIRECT) {
                $destination = NOBLOGREDIRECT;
            }
        } elseif (0 === strcasecmp($current_site->domain, $domain)) {
            /*
             * If the domain we were searching for matches the network's domain,
             * it's no use redirecting back to ourselves -- it'll cause a loop.
             * As we couldn't find a site, we're simply not installed.
             */
            return false;
        }
        return $destination;
    }
    // Figure out the current network's main site.
    if (empty($current_site->blog_id)) {
        $current_site->blog_id = get_main_site_id($current_site->id);
    }
    return true;
}

WordPress Version: 5.3

/**
 * Identifies the network and site of a requested domain and path and populates the
 * corresponding network and site global objects as part of the multisite bootstrap process.
 *
 * Prior to 4.6.0, this was a procedural block in `ms-settings.php`. It was wrapped into
 * a function to facilitate unit tests. It should not be used outside of core.
 *
 * Usually, it's easier to query the site first, which then declares its network.
 * In limited situations, we either can or must find the network first.
 *
 * If a network and site are found, a `true` response will be returned so that the
 * request can continue.
 *
 * If neither a network or site is found, `false` or a URL string will be returned
 * so that either an error can be shown or a redirect can occur.
 *
 * @since 4.6.0
 * @access private
 *
 * @global WP_Network $current_site The current network.
 * @global WP_Site    $current_blog The current site.
 *
 * @param string $domain    The requested domain.
 * @param string $path      The requested path.
 * @param bool   $subdomain Optional. Whether a subdomain (true) or subdirectory (false) configuration.
 *                          Default false.
 * @return bool|string True if bootstrap successfully populated `$current_blog` and `$current_site`.
 *                     False if bootstrap could not be properly completed.
 *                     Redirect URL if parts exist, but the request as a whole can not be fulfilled.
 */
function ms_load_current_site_and_network($domain, $path, $subdomain = false)
{
    global $current_site, $current_blog;
    // If the network is defined in wp-config.php, we can simply use that.
    if (defined('DOMAIN_CURRENT_SITE') && defined('PATH_CURRENT_SITE')) {
        $current_site = new stdClass();
        $current_site->id = defined('SITE_ID_CURRENT_SITE') ? SITE_ID_CURRENT_SITE : 1;
        $current_site->domain = DOMAIN_CURRENT_SITE;
        $current_site->path = PATH_CURRENT_SITE;
        if (defined('BLOG_ID_CURRENT_SITE')) {
            $current_site->blog_id = BLOG_ID_CURRENT_SITE;
        } elseif (defined('BLOGID_CURRENT_SITE')) {
            // deprecated.
            $current_site->blog_id = BLOGID_CURRENT_SITE;
        }
        if (0 === strcasecmp($current_site->domain, $domain) && 0 === strcasecmp($current_site->path, $path)) {
            $current_blog = get_site_by_path($domain, $path);
        } elseif ('/' !== $current_site->path && 0 === strcasecmp($current_site->domain, $domain) && 0 === stripos($path, $current_site->path)) {
            // If the current network has a path and also matches the domain and path of the request,
            // we need to look for a site using the first path segment following the network's path.
            $current_blog = get_site_by_path($domain, $path, 1 + count(explode('/', trim($current_site->path, '/'))));
        } else {
            // Otherwise, use the first path segment (as usual).
            $current_blog = get_site_by_path($domain, $path, 1);
        }
    } elseif (!$subdomain) {
        /*
         * A "subdomain" installation can be re-interpreted to mean "can support any domain".
         * If we're not dealing with one of these installations, then the important part is determining
         * the network first, because we need the network's path to identify any sites.
         */
        $current_site = wp_cache_get('current_network', 'site-options');
        if (!$current_site) {
            // Are there even two networks installed?
            $networks = get_networks(array('number' => 2));
            if (count($networks) === 1) {
                $current_site = array_shift($networks);
                wp_cache_add('current_network', $current_site, 'site-options');
            } elseif (empty($networks)) {
                // A network not found hook should fire here.
                return false;
            }
        }
        if (empty($current_site)) {
            $current_site = WP_Network::get_by_path($domain, $path, 1);
        }
        if (empty($current_site)) {
            /**
             * Fires when a network cannot be found based on the requested domain and path.
             *
             * At the time of this action, the only recourse is to redirect somewhere
             * and exit. If you want to declare a particular network, do so earlier.
             *
             * @since 4.4.0
             *
             * @param string $domain       The domain used to search for a network.
             * @param string $path         The path used to search for a path.
             */
            do_action('ms_network_not_found', $domain, $path);
            return false;
        } elseif ($path === $current_site->path) {
            $current_blog = get_site_by_path($domain, $path);
        } else {
            // Search the network path + one more path segment (on top of the network path).
            $current_blog = get_site_by_path($domain, $path, substr_count($current_site->path, '/'));
        }
    } else {
        // Find the site by the domain and at most the first path segment.
        $current_blog = get_site_by_path($domain, $path, 1);
        if ($current_blog) {
            $current_site = WP_Network::get_instance($current_blog->site_id ? $current_blog->site_id : 1);
        } else {
            // If you don't have a site with the same domain/path as a network, you're pretty screwed, but:
            $current_site = WP_Network::get_by_path($domain, $path, 1);
        }
    }
    // The network declared by the site trumps any constants.
    if ($current_blog && $current_blog->site_id != $current_site->id) {
        $current_site = WP_Network::get_instance($current_blog->site_id);
    }
    // No network has been found, bail.
    if (empty($current_site)) {
        /** This action is documented in wp-includes/ms-settings.php */
        do_action('ms_network_not_found', $domain, $path);
        return false;
    }
    // During activation of a new subdomain, the requested site does not yet exist.
    if (empty($current_blog) && wp_installing()) {
        $current_blog = new stdClass();
        $current_blog->blog_id = 1;
        $blog_id = 1;
        $current_blog->public = 1;
    }
    // No site has been found, bail.
    if (empty($current_blog)) {
        // We're going to redirect to the network URL, with some possible modifications.
        $scheme = is_ssl() ? 'https' : 'http';
        $destination = "{$scheme}://{$current_site->domain}{$current_site->path}";
        /**
         * Fires when a network can be determined but a site cannot.
         *
         * At the time of this action, the only recourse is to redirect somewhere
         * and exit. If you want to declare a particular site, do so earlier.
         *
         * @since 3.9.0
         *
         * @param object $current_site The network that had been determined.
         * @param string $domain       The domain used to search for a site.
         * @param string $path         The path used to search for a site.
         */
        do_action('ms_site_not_found', $current_site, $domain, $path);
        if ($subdomain && !defined('NOBLOGREDIRECT')) {
            // For a "subdomain" installation, redirect to the signup form specifically.
            $destination .= 'wp-signup.php?new=' . str_replace('.' . $current_site->domain, '', $domain);
        } elseif ($subdomain) {
            // For a "subdomain" installation, the NOBLOGREDIRECT constant
            // can be used to avoid a redirect to the signup form.
            // Using the ms_site_not_found action is preferred to the constant.
            if ('%siteurl%' !== NOBLOGREDIRECT) {
                $destination = NOBLOGREDIRECT;
            }
        } elseif (0 === strcasecmp($current_site->domain, $domain)) {
            /*
             * If the domain we were searching for matches the network's domain,
             * it's no use redirecting back to ourselves -- it'll cause a loop.
             * As we couldn't find a site, we're simply not installed.
             */
            return false;
        }
        return $destination;
    }
    // Figure out the current network's main site.
    if (empty($current_site->blog_id)) {
        $current_site->blog_id = get_main_site_id($current_site->id);
    }
    return true;
}

WordPress Version: 4.9

/**
 * Identifies the network and site of a requested domain and path and populates the
 * corresponding network and site global objects as part of the multisite bootstrap process.
 *
 * Prior to 4.6.0, this was a procedural block in `ms-settings.php`. It was wrapped into
 * a function to facilitate unit tests. It should not be used outside of core.
 *
 * Usually, it's easier to query the site first, which then declares its network.
 * In limited situations, we either can or must find the network first.
 *
 * If a network and site are found, a `true` response will be returned so that the
 * request can continue.
 *
 * If neither a network or site is found, `false` or a URL string will be returned
 * so that either an error can be shown or a redirect can occur.
 *
 * @since 4.6.0
 * @access private
 *
 * @global WP_Network $current_site The current network.
 * @global WP_Site    $current_blog The current site.
 *
 * @param string $domain    The requested domain.
 * @param string $path      The requested path.
 * @param bool   $subdomain Optional. Whether a subdomain (true) or subdirectory (false) configuration.
 *                          Default false.
 * @return bool|string True if bootstrap successfully populated `$current_blog` and `$current_site`.
 *                     False if bootstrap could not be properly completed.
 *                     Redirect URL if parts exist, but the request as a whole can not be fulfilled.
 */
function ms_load_current_site_and_network($domain, $path, $subdomain = false)
{
    global $current_site, $current_blog;
    // If the network is defined in wp-config.php, we can simply use that.
    if (defined('DOMAIN_CURRENT_SITE') && defined('PATH_CURRENT_SITE')) {
        $current_site = new stdClass();
        $current_site->id = defined('SITE_ID_CURRENT_SITE') ? SITE_ID_CURRENT_SITE : 1;
        $current_site->domain = DOMAIN_CURRENT_SITE;
        $current_site->path = PATH_CURRENT_SITE;
        if (defined('BLOG_ID_CURRENT_SITE')) {
            $current_site->blog_id = BLOG_ID_CURRENT_SITE;
        } elseif (defined('BLOGID_CURRENT_SITE')) {
            // deprecated.
            $current_site->blog_id = BLOGID_CURRENT_SITE;
        }
        if (0 === strcasecmp($current_site->domain, $domain) && 0 === strcasecmp($current_site->path, $path)) {
            $current_blog = get_site_by_path($domain, $path);
        } elseif ('/' !== $current_site->path && 0 === strcasecmp($current_site->domain, $domain) && 0 === stripos($path, $current_site->path)) {
            // If the current network has a path and also matches the domain and path of the request,
            // we need to look for a site using the first path segment following the network's path.
            $current_blog = get_site_by_path($domain, $path, 1 + count(explode('/', trim($current_site->path, '/'))));
        } else {
            // Otherwise, use the first path segment (as usual).
            $current_blog = get_site_by_path($domain, $path, 1);
        }
    } elseif (!$subdomain) {
        /*
         * A "subdomain" installation can be re-interpreted to mean "can support any domain".
         * If we're not dealing with one of these installations, then the important part is determining
         * the network first, because we need the network's path to identify any sites.
         */
        if (!$current_site = wp_cache_get('current_network', 'site-options')) {
            // Are there even two networks installed?
            $networks = get_networks(array('number' => 2));
            if (count($networks) === 1) {
                $current_site = array_shift($networks);
                wp_cache_add('current_network', $current_site, 'site-options');
            } elseif (empty($networks)) {
                // A network not found hook should fire here.
                return false;
            }
        }
        if (empty($current_site)) {
            $current_site = WP_Network::get_by_path($domain, $path, 1);
        }
        if (empty($current_site)) {
            /**
             * Fires when a network cannot be found based on the requested domain and path.
             *
             * At the time of this action, the only recourse is to redirect somewhere
             * and exit. If you want to declare a particular network, do so earlier.
             *
             * @since 4.4.0
             *
             * @param string $domain       The domain used to search for a network.
             * @param string $path         The path used to search for a path.
             */
            do_action('ms_network_not_found', $domain, $path);
            return false;
        } elseif ($path === $current_site->path) {
            $current_blog = get_site_by_path($domain, $path);
        } else {
            // Search the network path + one more path segment (on top of the network path).
            $current_blog = get_site_by_path($domain, $path, substr_count($current_site->path, '/'));
        }
    } else {
        // Find the site by the domain and at most the first path segment.
        $current_blog = get_site_by_path($domain, $path, 1);
        if ($current_blog) {
            $current_site = WP_Network::get_instance($current_blog->site_id ? $current_blog->site_id : 1);
        } else {
            // If you don't have a site with the same domain/path as a network, you're pretty screwed, but:
            $current_site = WP_Network::get_by_path($domain, $path, 1);
        }
    }
    // The network declared by the site trumps any constants.
    if ($current_blog && $current_blog->site_id != $current_site->id) {
        $current_site = WP_Network::get_instance($current_blog->site_id);
    }
    // No network has been found, bail.
    if (empty($current_site)) {
        /** This action is documented in wp-includes/ms-settings.php */
        do_action('ms_network_not_found', $domain, $path);
        return false;
    }
    // During activation of a new subdomain, the requested site does not yet exist.
    if (empty($current_blog) && wp_installing()) {
        $current_blog = new stdClass();
        $current_blog->blog_id = $blog_id = 1;
        $current_blog->public = 1;
    }
    // No site has been found, bail.
    if (empty($current_blog)) {
        // We're going to redirect to the network URL, with some possible modifications.
        $scheme = is_ssl() ? 'https' : 'http';
        $destination = "{$scheme}://{$current_site->domain}{$current_site->path}";
        /**
         * Fires when a network can be determined but a site cannot.
         *
         * At the time of this action, the only recourse is to redirect somewhere
         * and exit. If you want to declare a particular site, do so earlier.
         *
         * @since 3.9.0
         *
         * @param object $current_site The network that had been determined.
         * @param string $domain       The domain used to search for a site.
         * @param string $path         The path used to search for a site.
         */
        do_action('ms_site_not_found', $current_site, $domain, $path);
        if ($subdomain && !defined('NOBLOGREDIRECT')) {
            // For a "subdomain" installation, redirect to the signup form specifically.
            $destination .= 'wp-signup.php?new=' . str_replace('.' . $current_site->domain, '', $domain);
        } elseif ($subdomain) {
            // For a "subdomain" installation, the NOBLOGREDIRECT constant
            // can be used to avoid a redirect to the signup form.
            // Using the ms_site_not_found action is preferred to the constant.
            if ('%siteurl%' !== NOBLOGREDIRECT) {
                $destination = NOBLOGREDIRECT;
            }
        } elseif (0 === strcasecmp($current_site->domain, $domain)) {
            /*
             * If the domain we were searching for matches the network's domain,
             * it's no use redirecting back to ourselves -- it'll cause a loop.
             * As we couldn't find a site, we're simply not installed.
             */
            return false;
        }
        return $destination;
    }
    // Figure out the current network's main site.
    if (empty($current_site->blog_id)) {
        $current_site->blog_id = get_main_site_id($current_site->id);
    }
    return true;
}

WordPress Version: 4.6

/**
 * Identifies the network and site of a requested domain and path and populates the
 * corresponding network and site global objects as part of the multisite bootstrap process.
 *
 * Prior to 4.6.0, this was a procedural block in `ms-settings.php`. It was wrapped into
 * a function to facilitate unit tests. It should not be used outside of core.
 *
 * Usually, it's easier to query the site first, which then declares its network.
 * In limited situations, we either can or must find the network first.
 *
 * If a network and site are found, a `true` response will be returned so that the
 * request can continue.
 *
 * If neither a network or site is found, `false` or a URL string will be returned
 * so that either an error can be shown or a redirect can occur.
 *
 * @since 4.6.0
 * @access private
 *
 * @global wpdb       $wpdb         WordPress database abstraction object.
 * @global WP_Network $current_site The current network.
 * @global WP_Site    $current_blog The current site.
 *
 * @param string $domain    The requested domain.
 * @param string $path      The requested path.
 * @param bool   $subdomain Optional. Whether a subdomain (true) or subdirectory (false) configuration.
 *                          Default false.
 * @return bool|string True if bootstrap successfully populated `$current_blog` and `$current_site`.
 *                     False if bootstrap could not be properly completed.
 *                     Redirect URL if parts exist, but the request as a whole can not be fulfilled.
 */
function ms_load_current_site_and_network($domain, $path, $subdomain = false)
{
    global $wpdb, $current_site, $current_blog;
    // If the network is defined in wp-config.php, we can simply use that.
    if (defined('DOMAIN_CURRENT_SITE') && defined('PATH_CURRENT_SITE')) {
        $current_site = new stdClass();
        $current_site->id = defined('SITE_ID_CURRENT_SITE') ? SITE_ID_CURRENT_SITE : 1;
        $current_site->domain = DOMAIN_CURRENT_SITE;
        $current_site->path = PATH_CURRENT_SITE;
        if (defined('BLOG_ID_CURRENT_SITE')) {
            $current_site->blog_id = BLOG_ID_CURRENT_SITE;
        } elseif (defined('BLOGID_CURRENT_SITE')) {
            // deprecated.
            $current_site->blog_id = BLOGID_CURRENT_SITE;
        }
        if (0 === strcasecmp($current_site->domain, $domain) && 0 === strcasecmp($current_site->path, $path)) {
            $current_blog = get_site_by_path($domain, $path);
        } elseif ('/' !== $current_site->path && 0 === strcasecmp($current_site->domain, $domain) && 0 === stripos($path, $current_site->path)) {
            // If the current network has a path and also matches the domain and path of the request,
            // we need to look for a site using the first path segment following the network's path.
            $current_blog = get_site_by_path($domain, $path, 1 + count(explode('/', trim($current_site->path, '/'))));
        } else {
            // Otherwise, use the first path segment (as usual).
            $current_blog = get_site_by_path($domain, $path, 1);
        }
    } elseif (!$subdomain) {
        /*
         * A "subdomain" install can be re-interpreted to mean "can support any domain".
         * If we're not dealing with one of these installs, then the important part is determining
         * the network first, because we need the network's path to identify any sites.
         */
        if (!$current_site = wp_cache_get('current_network', 'site-options')) {
            // Are there even two networks installed?
            $one_network = $wpdb->get_row("SELECT * FROM {$wpdb->site} LIMIT 2");
            // [sic]
            if (1 === $wpdb->num_rows) {
                $current_site = new WP_Network($one_network);
                wp_cache_add('current_network', $current_site, 'site-options');
            } elseif (0 === $wpdb->num_rows) {
                // A network not found hook should fire here.
                return false;
            }
        }
        if (empty($current_site)) {
            $current_site = WP_Network::get_by_path($domain, $path, 1);
        }
        if (empty($current_site)) {
            /**
             * Fires when a network cannot be found based on the requested domain and path.
             *
             * At the time of this action, the only recourse is to redirect somewhere
             * and exit. If you want to declare a particular network, do so earlier.
             *
             * @since 4.4.0
             *
             * @param string $domain       The domain used to search for a network.
             * @param string $path         The path used to search for a path.
             */
            do_action('ms_network_not_found', $domain, $path);
            return false;
        } elseif ($path === $current_site->path) {
            $current_blog = get_site_by_path($domain, $path);
        } else {
            // Search the network path + one more path segment (on top of the network path).
            $current_blog = get_site_by_path($domain, $path, substr_count($current_site->path, '/'));
        }
    } else {
        // Find the site by the domain and at most the first path segment.
        $current_blog = get_site_by_path($domain, $path, 1);
        if ($current_blog) {
            $current_site = WP_Network::get_instance($current_blog->site_id ? $current_blog->site_id : 1);
        } else {
            // If you don't have a site with the same domain/path as a network, you're pretty screwed, but:
            $current_site = WP_Network::get_by_path($domain, $path, 1);
        }
    }
    // The network declared by the site trumps any constants.
    if ($current_blog && $current_blog->site_id != $current_site->id) {
        $current_site = WP_Network::get_instance($current_blog->site_id);
    }
    // No network has been found, bail.
    if (empty($current_site)) {
        /** This action is documented in wp-includes/ms-settings.php */
        do_action('ms_network_not_found', $domain, $path);
        return false;
    }
    // During activation of a new subdomain, the requested site does not yet exist.
    if (empty($current_blog) && wp_installing()) {
        $current_blog = new stdClass();
        $current_blog->blog_id = $blog_id = 1;
        $current_blog->public = 1;
    }
    // No site has been found, bail.
    if (empty($current_blog)) {
        // We're going to redirect to the network URL, with some possible modifications.
        $scheme = is_ssl() ? 'https' : 'http';
        $destination = "{$scheme}://{$current_site->domain}{$current_site->path}";
        /**
         * Fires when a network can be determined but a site cannot.
         *
         * At the time of this action, the only recourse is to redirect somewhere
         * and exit. If you want to declare a particular site, do so earlier.
         *
         * @since 3.9.0
         *
         * @param object $current_site The network that had been determined.
         * @param string $domain       The domain used to search for a site.
         * @param string $path         The path used to search for a site.
         */
        do_action('ms_site_not_found', $current_site, $domain, $path);
        if ($subdomain && !defined('NOBLOGREDIRECT')) {
            // For a "subdomain" install, redirect to the signup form specifically.
            $destination .= 'wp-signup.php?new=' . str_replace('.' . $current_site->domain, '', $domain);
        } elseif ($subdomain) {
            // For a "subdomain" install, the NOBLOGREDIRECT constant
            // can be used to avoid a redirect to the signup form.
            // Using the ms_site_not_found action is preferred to the constant.
            if ('%siteurl%' !== NOBLOGREDIRECT) {
                $destination = NOBLOGREDIRECT;
            }
        } elseif (0 === strcasecmp($current_site->domain, $domain)) {
            /*
             * If the domain we were searching for matches the network's domain,
             * it's no use redirecting back to ourselves -- it'll cause a loop.
             * As we couldn't find a site, we're simply not installed.
             */
            return false;
        }
        return $destination;
    }
    // Figure out the current network's main site.
    if (empty($current_site->blog_id)) {
        if ($current_blog->domain === $current_site->domain && $current_blog->path === $current_site->path) {
            $current_site->blog_id = $current_blog->blog_id;
        } elseif (!$current_site->blog_id = wp_cache_get('network:' . $current_site->id . ':main_site', 'site-options')) {
            $current_site->blog_id = $wpdb->get_var($wpdb->prepare("SELECT blog_id FROM {$wpdb->blogs} WHERE domain = %s AND path = %s", $current_site->domain, $current_site->path));
            wp_cache_add('network:' . $current_site->id . ':main_site', $current_site->blog_id, 'site-options');
        }
    }
    return true;
}