【CodeIgniter3.0】作成したデータベース用ドライバを読み込む

MY_Loader.php

<?php

defined('BASEPATH') OR exit('No direct script access allowed');

class MY_Loader extends CI_Loader {

    /**
     * Database Loader
     *
     * @param	mixed	$params		Database configuration options
     * @param	bool	$return 	Whether to return the database object
     * @param	bool	$query_builder	Whether to enable Query Builder
     * 					(overrides the configuration setting)
     *
     * @return	object|bool	Database object if $return is set to TRUE,
     * 					FALSE on failure, CI_Loader instance in any other case
     */
    public function database($params = '', $return = FALSE, $query_builder = NULL)
    {
        // Grab the super object
        $CI = & get_instance();

        // Do we even need to load the database class?
        if ($return === FALSE && $query_builder === NULL && isset($CI->db) && is_object($CI->db) && !empty($CI->db->conn_id)) {
            return FALSE;
        }

        require_once(BASEPATH . 'database/DB.php');

        $DB = & DB($params, $query_builder);

        // ユーザードライバ読み込み
        $driver = config_item('subclass_prefix') . 'DB_' . $DB->dbdriver . '_driver';
        $driver_file = APPPATH . 'libraries/database/drivers/' . $DB->dbdriver . '/' . $driver . '.php';

        if (file_exists($driver_file)) {
            require_once($driver_file);
            $DB = new $driver(get_object_vars($DB));

            if (!empty($DB->subdriver)) {
                // ユーザーサブドライバ読み込み
                $driver = config_item('subclass_prefix') . 'DB_' . $DB->dbdriver . '_' . $DB->subdriver . '_driver';
                $driver_file = APPPATH . 'libraries/database/drivers/' . $DB->dbdriver . '/subdrivers/' . $driver . '.php';

                if (file_exists($driver_file)) {
                    require_once($driver_file);
                    $DB = new $driver(get_object_vars($DB));
                }
            }

            $DB->initialize();
        }

        if ($return === TRUE) {
            return $DB;
        }

        // Initialize the db variable. Needed to prevent
        // reference errors with some configurations
        $CI->db = '';

        // Load the DB class
        $CI->db = $DB;
        return $this;
    }

}