1<?php 2 3class Logger { 4 static $instance = null; 5 6 /* protected */ function __construct() { 7 } 8 9 /* public */ function log($message) { 10 error_log($message); 11 } 12 13 /* static */ function get_instance() { 14 if (is_null(Logger::$instance)) { 15 Logger::$instance = new Logger(); 16 }; 17 18 return Logger::$instance; 19 } 20 21 /* static */ function set_instance($instance) { 22 Logger::$instance = $instance; 23 } 24} 25 26?>