How can I use custom exception pages with ZF2? - error-handling

Question

I need to redirect a user to an error page (view/error/403.phtml) from within the Module.php of a module called Admin when a user is not allowed to access the specific resource. I have been searching for a solution to this, but so far had no success. The best I found was this question, the accepted answer to which doesn't work for me (and I currently cannot add comments to the linked question because I don't have the required reputation level) - the page is displayed as if there is no redirect at all and the user is allowed to access it. I have tried to replace the redirecting code with a simple die; to test if the isAllowed() is working properly, and it correctly shows a blank page, so the problem lies in the redirection itself.
Relevant code in Module.php is:
public function onBootstrap(MvcEvent $e)
{
$this->initAcl($e);
$eventManager = $e->getApplication()->getEventManager();
$eventManager->attach('route', array($this, 'checkAcl'));
$moduleRouteListener = new ModuleRouteListener();
$moduleRouteListener->attach($eventManager);
}
public function checkAcl(MvcEvent $e)
{
// ...
if (!$this->acl->isAllowed($userRole, $controller, $privilege))
{
$response = $e->getResponse();
$response->setHeaders($response->getHeaders()->addHeaderLine('Location', $e->getRequest()->getBaseurl() . '/error/403'));
$response->setStatusCode(403);
$response->sendHeaders();
}
// ...
}
module.config.php
'view_manager' => array(
'display_exceptions' => true,
'exception_template' => 'error/403',
'template_map' => array(
'layout/layout' => __DIR__ . '/../view/layout/admin_layout.phtml',
'error/403' => __DIR__ . '/../view/error/403.phtml',
'error/404' => __DIR__ . '/../view/error/404.phtml',
'error/index' => __DIR__ . '/../view/error/index.phtml',
),
'template_path_stack' => array(
'Admin' => __DIR__ . '/../view',
),
'strategies' => array(
'ViewJsonStrategy',
),
),
If I add the line
throw new \Exception($translator->translate('Access denied'));
after the code for redirection, I do get redirected to URL http://[servername]/error/403, but the contents of the page is, instead of my custom 403.phtml, a styled (with layout) 404 error page, stating that "The requested URL could not be matched by routing."

Answer 1

A better way to achieve what you want is to trigger a dispatch.error event in your checkAcl function rather than trying to do a redirect. You can then handle this event and display the 403 page.
To trigger the event:
if (!$this->acl->isAllowed($userRole, $controller, $privilege))
{
$app = $e->getTarget();
$route = $e->getRouteMatch();
$e->setError('ACL_ACCESS_DENIED') // Pick your own value, would be better to use a const
->setParam('route', $route->getMatchedRouteName());
$app->getEventManager()->trigger('dispatch.error', $e);
}
Then in your onBootstrap add a listener for the dispatch.error event:
use Zend\Mvc\MvcEvent;
...
$eventManager->attach(MvcEvent::EVENT_DISPATCH_ERROR, <any callable>, -999);
In your callback for dispatch.error event you just attached to:
$error = $event->getError();
if (empty($error) || $error != "ACL_ACCESS_DENIED") {
return;
}
$result = $event->getResult();
if ($result instanceof StdResponse) {
return;
}
$baseModel = new ViewModel();
$baseModel->setTemplate('layout/layout');
$model = new ViewModel();
$model->setTemplate('error/403');
$baseModel->addChild($model);
$baseModel->setTerminal(true);
$event->setViewModel($baseModel);
$response = $event->getResponse();
$response->setStatusCode(403);
$event->setResponse($response);
$event->setResult($baseModel);
return false;