How to properly exit from a custom blackhole handler? - cakephp

Question

My problem is fairly basic: whenever an action in CakePHP is blackholed, I want to display a custom error page; the default behaviour of Cake to display a "File not found" message confuses the hell out of users (not to mention developers). So I came up with this, by searching the docs and StackOverflow:
class TestsController extends AppController
{
public $components = array ('Security');
public function beforeFilter ()
{
parent::beforeFilter ();
$this->Security->blackHoleCallback = 'blackhole';
$this->Security->csrfExpires = '+5 seconds'; // for testing
}
public function index ()
{
}
public function doit ()
{
$this->log ('Performing request; entry = ' . $this->data['foo'], 'tests');
$this->set ('foo', $this->data['foo']);
}
public function blackhole ($type)
{
$this->log ('Request has been blackholed: ' . $type, 'tests');
$this->render ('/Errors/blackhole');
$this->response->send ();
exit ();
}
}
In index.ctp there is a simple form with a single textbox, that commits to doit (excluded for brevity). This works, but I have one major issue: the exit() in the blackhole() function. The problem is, if I do not exit here doit() is still called, even if the request is blackholed, as evidenced by the log:
2013-01-30 15:37:21 Tests: Request has been blackholed: csrf
2013-01-30 15:37:21 Tests: Performing request; entry = kfkfkfkf
This is clearly not what you expect. The Cake documentation hints at using (custom) exceptions to stop processing in blackhole(), but that:
completely beats the purpose of using a custom handler;
adds another layer of complexity to something that should be simple.
My question is: is there a proper way to do an "exit" from blackhole() so that Cake does all the rendering/cleanup/etc. that it usually does; I already had to add $this->response->send() to force output to the browser. Or, althernatively, a way to tell Cake to skip calling doit() after blackhole().

Answer 1

My suggestion would be to redirect in your blackhole.
This is done e.g. here in the cookbook http://book.cakephp.org/2.0/en/core-libraries/components/security-component.html#usage
$this->redirect(array('controller' => 'test', 'action' => 'index'));
A redirect will issue an exit (http://book.cakephp.org/2.0/en/controllers.html#flow-control).
You can also send something nice to the user if you want, before the redirect:
$this->Session->setFlash('What are you doing!?');

Answer 2

In your blackhole callback you could just throw an exception with required message. That would render the proper error page and get logged too (assuming you have turned on logging for errors in core.php).