Ticket #5733: bp-multi-network.php

<?php

/**
 * Plugin Name: BP Multi Network
 * Plugin URI:  https://wordpress.org/plugins/bp-multi-network/
 * Description: Unique BuddyPress networks in your WordPress multi-network installation
 * Version:     0.2.0
 * Author:      The BuddyPress Community
 * Author URI:  http://buddypress.org
*/

/**
 * The main BuddyPress multi-network class
 *
 * This class adds filters to three places in BuddyPress to intercept and modify
 * database table prefixes based on the current network.
 */
class BP_Multi_Network {

        /**
         * Array of BuddyPress user-meta keys
         *
         * @var array
         */
        private $user_meta_keys = array(
                'last_activity'                             => false,
                'bp_new_mention_count'                      => false,
                'bp_favorite_activities'                    => false,
                'bp_latest_update'                          => false,
                'total_friend_count'                        => false,
                'total_group_count'                         => false,
                'notification_activity_new_mention'         => false,
                'notification_activity_new_reply'           => false,
                'notification_groups_group_updated'         => false,
                'notification_groups_membership_request'    => false,
                'notification_membership_request_completed' => false,
                'notification_groups_admin_promotion'       => false,
                'notification_groups_invite'                => false,
                'notification_messages_new_message'         => false,
                'notification_messages_new_notice'          => false,
                'closed_notices'                            => false,
                'profile_last_updated'                      => false
        );

        /** Filters ***************************************************************/

        /**
         * Attach filters to what are usually considered "global" values, and modify
         * them based on the currently loaded WordPress network of sites.
         *
         * - Global cache key
         * - Table prefix
         * - User meta key
         */
        public function __construct() {
                add_filter( 'bp_core_get_global_cache_key', array( $this, 'filter_global_cache_key' ) );
                add_filter( 'bp_core_get_table_prefix',     array( $this, 'filter_table_prefix'     ) );
                add_filter( 'bp_get_user_meta_key',         array( $this, 'filter_user_meta_key'    ) );
        }

        /**
         * Filter the "global" cache key and maybe add a network ID
         *
         * @param string $key
         * @return string
         */
        public function filter_global_cache_key( $key = 'bp' ) {

                // Override prefix if not main network and there is a prefix match
                if ( ! $this->is_main_network() && ( true === $this->is_base_cache_key( $key ) ) ) {
                        $key = $this->get_network_cache_key() . $key;
                }

                // Use this network's prefix
                return $key;
        }

        /**
         * Filter the DB table prefix and maybe add a network ID
         *
         * @param string $prefix
         * @return string
         */
        public function filter_table_prefix( $prefix = '' ) {

                // Override prefix if not main network and there is a prefix match
                if ( ! $this->is_main_network() && ( true === $this->is_base_db_prefix( $prefix ) ) ) {
                        $prefix = $this->get_network_db_prefix();
                }

                // Use this network's prefix
                return $prefix;
        }

        /**
         * Filter the appropriate BuddyPress user-meta keys and prefix them with the
         * ID of the network they belong to.
         *
         * @param string $key
         * @return string
         */
        public function filter_user_meta_key( $key = '' ) {

                // Bail if key is not BuddyPress user meta
                if ( ! isset( $this->user_meta_keys[ $key ] ) ) {
                        return $key;
                }

                // Bail if on the main network
                if ( $this->is_main_network() ) {
                        return $key;
                }

                // Set the user meta key to the new prefix
                if ( false === $this->user_meta_keys[ $key ] ) {
                        $this->user_meta_keys[ $key ] = $this->get_network_db_prefix() . $key;
                }

                // Return the modified user meta key
                return $this->user_meta_keys[ $key ];
        }

        /** Helpers ***************************************************************/

        /**
         * Whether or not the current DB query is from the main network.
         *
         * The main network is typically ID 1 (and does not have a modified prefix)
         * but we also need to check for the PRIMARY_NETWORK_ID constant introduced
         * in WordPress 3.7 for more sophisticated installations.
         *
         * @global object $wpdb
         * @return boolean
         */
        private function is_main_network() {
                global $wpdb;

                // Use primary network ID if defined
                $primary_network_id = defined( 'PRIMARY_NETWORK_ID' )
                        ? (int) PRIMARY_NETWORK_ID
                        : 1;

                return (bool) ( $wpdb->siteid === $primary_network_id );
        }

        /** Cache Keys ************************************************************/

        /**
         * Compare a given cache-key with BuddyPress's "global" cache-key.
         *
         * @param string $key
         * @return string
         */
        private function is_base_cache_key( $key = '' ) {
                return (bool) ( 'bp' === $key );
        }

        /**
         * Return the cache-key for the current network
         *
         * Note that we're using the prefix for the root-blog, and not the network
         * ID itself. This is because BuddyPress stores much of its data in the
         * root-blog options table VS the sitemeta table.
         *
         * @global object $wpdb
         * @return string
         */
        private function get_network_cache_key() {
                global $wpdb;
                return $wpdb->get_blog_prefix( get_current_site()->blog_id );
        }

        /** DB ********************************************************************/

        /**
         * Compare a given DB table prefix with the base DB prefix.
         *
         * @global object $wpdb
         * @param string $prefix
         * @return string
         */
        private function is_base_db_prefix( $prefix = '' ) {
                global $wpdb;
                return (bool) ( $prefix === $wpdb->base_prefix );
        }

        /**
         * Return the DB table prefix for the current network
         *
         * Note that we're using the prefix for the root-blog, and not the network
         * ID itself. This is because BuddyPress stores much of its data in the
         * root-blog options table VS the sitemeta table.
         *
         * @global object $wpdb
         * @return string
         */
        private function get_network_db_prefix() {
                global $wpdb;
                return $wpdb->get_blog_prefix( get_current_site()->blog_id );
        }
}
new BP_Multi_Network();