How to gracefully disable a PHP logging class

So i've got this logger (actually a wrapper), which is accessed all over the app with Log::getInstance()->log_this or ->log_that, etc. There is a config param in an ini which turns logging off, but the implementation to disable LogWrapper isn't quite right:

private function __construct() {
    if(config::get('logging_enabled')) {
            $this->logger = new Log();
        } 
        //else?
}

public static function getInstance() {
    if(self::$_instance == NULL)开发者_开发问答 {
        self::$_instance = new LogWrapper();
    }
    return self::$_instance;
}

Calls to getInstance()->any_method delegate to the $logger instance, but will fail because $logger isn't anything.

Where can i stop this flow within this class? It's not an option to modify the Log class, nor can i go through each call in the app to LogWrapper. I can't seem to get my head around this, and I know one smartly-placed line would fix it...

thanks for any help!

Why not implement a dummy logger-class, that wouldn't log anything ?

And, then, instanciate either Log or that dummy-useless class, depending on the configuration :

if(config::get('logging_enabled')) {
    $this->logger = new Log();
} 
else {
    $this->logger = new DummyLogThatDoesntLog();
}