Ticket #15467: blog-user-tables.php

<?php
/*
Plugin name: Separate Blog User Tables
Plugin URI: http://core.trac.wordpress.org/ticket/15467
Description: Configure and implements separate User Tables for each blog in the same Multisite Network.
Author: lightningspirit
Author URI: http://vcarvalho.com/
Version: 0.1
*/

/**
 * This file actually do all do work on creating user tables for the
 * current blog if they are not already created.
 * 
 * 
 * 
 * NOTE: Don't use this file in a production environment.
 * Not stable. Use only for test purposes.
 * 
 * 
 * 
 * Instalation Procedure: 
 * ----------------------
 * 1. Put inside wp-contents/mu-plugins/
 * 
 * 
 * @package WordPress
 * @since 3.4
 */



/**
 * Fire on Must use plugins loading process
 */
add_action( 'muplugins_loaded', '_separate_blog_user_tables_create' );


/**
 * _separate_blog_user_tables_create
 * 
 * This code will create new user tables if they are not present in
 * the DB for the current blog request.
 * TODO: replicate the administrator of the blog in those custom tables
 * or at least hook the authentication process to load the users 
 * from the global users table too
 * 
 * @since 0.1
 * @uses dbDelta
 */
function _separate_blog_user_tables_create() {
        global $wpdb, $blog_id;
        
        /** Lets set the name of the custom Users tables */
        $users_table     = $wpdb->prefix . 'users';
        $user_meta_table = $wpdb->prefix . 'usermeta';
        
        
        /** Check if the tables were already created, if so return and have fun! :) */
        if ( $wpdb->get_var( "SHOW TABLES LIKE '$users_table'" ) == $users_table )
                return;
                
        
        /** 
         * Hum... it seems that it is the first time that you are running
         * this code in the current blog...
         * We have to create the custom tables, lets do it!
         * 
         * Require the dbDelta() function
         */     
        require_once( ABSPATH . 'wp-admin/includes/upgrade.php' );
        
        /** Create user meta table */
        dbDelta( "CREATE TABLE IF NOT EXISTS `$user_meta_table` (
          `umeta_id` bigint(20) unsigned NOT NULL AUTO_INCREMENT,
          `user_id` bigint(20) unsigned NOT NULL DEFAULT '0',
          `meta_key` varchar(255) DEFAULT NULL,
          `meta_value` longtext,
          PRIMARY KEY (`umeta_id`),
          KEY `user_id` (`user_id`),
          KEY `meta_key` (`meta_key`)
        );" );
        
        /** Create users table **/
        dbDelta( "CREATE TABLE IF NOT EXISTS `$users_table` (
          `ID` bigint(20) unsigned NOT NULL AUTO_INCREMENT,
          `user_login` varchar(60) NOT NULL DEFAULT '',
          `user_pass` varchar(64) NOT NULL DEFAULT '',
          `user_nicename` varchar(50) NOT NULL DEFAULT '',
          `user_email` varchar(100) NOT NULL DEFAULT '',
          `user_url` varchar(100) NOT NULL DEFAULT '',
          `user_registered` datetime NOT NULL DEFAULT '0000-00-00 00:00:00',
          `user_activation_key` varchar(60) NOT NULL DEFAULT '',
          `user_status` int(11) NOT NULL DEFAULT '0',
          `display_name` varchar(250) NOT NULL DEFAULT '',
          `spam` tinyint(2) NOT NULL DEFAULT '0',
          `deleted` tinyint(2) NOT NULL DEFAULT '0',
          PRIMARY KEY (`ID`),
          KEY `user_login_key` (`user_login`),
          KEY `user_nicename` (`user_nicename`)
        );" );
        
        /** TODO: Replicate current user on those tables */
        
}