/**
* Not Found Handler
*
* This method defines or invokes the application-wide Not Found handler.
* There are two contexts in which this method may be invoked:
*
* 1. When declaring the handler:
*
* If the $callable parameter is not null and is callable, this
* method will register the callable to be invoked when no
* routes match the current HTTP request. It WILL NOT invoke the callable.
*
* 2. When invoking the handler:
*
* If the $callable parameter is null, Slim assumes you want
* to invoke an already-registered handler. If the handler has been
* registered and is callable, it is invoked and sends a 404 HTTP Response
* whose body is the output of the Not Found handler.
*
* @param mixed $callable Anything that returns true for is_callable()
*/
public function notFound($callable = null)
{
if (!is_null($callable)) {
$this->router->notFound($callable);
} else {
ob_start();
$customNotFoundHandler = $this->router->notFound();
if (is_callable($customNotFoundHandler)) {
call_user_func($customNotFoundHandler);
} else {
call_user_func(array($this, 'defaultNotFound'));
}
$this->halt(404, ob_get_clean());
}
}
