Silex: error handlers for specific types of exceptions

Question

Is it possible in Silex to use an error handler based on which exception is thrown?

I know that this is possible with a single exception handler and a switch statement in the class name for the generated exception, but for me it seems that the "Silex" method is cleaner but does not work.

Here is how I could expect it to work

<?php // Handle access denied errors $app->error(function (\App\Rest\Exception\AccessDenied $e) { $message = $e->getMessage() ?: 'Access denied!'; return new Response($message, 403); }); // Handle Resource not found errors $app->error(function (\App\Rest\Exception\ResourceNotFound $e) { $message = $e->getMessage() ?: 'Resource not found!'; return new Response($message, 404); }); // Handle other exception as 500 errors $app->error(function (\Exception $e, $code) { return new Response($e->getMessage(), $code); }); 

The problem is that when I throw a ResourceNotFound exception in my controller, the error handler associated with AccessDenied is executed

Fatal error allowed: argument 1 passed to {clos} () must be an instance of App \ Rest \ Exception \ AccessDenied, an instance of App \ Rest \ Exception \ ResourceNotFound specified

Is this achievable differently, or should I just populate everything in a handler that works with general exceptions and include the type of exception thrown?

PS: I know the $app->abort() method, but I prefer to work with exceptions

Answer 1

EDIT: This feature has now become the core of Silex!

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This is currently not possible. Right now you will have to either have one handler with the switch statement, or many handlers with if ($e instanceof MyException) each.

I like the idea, but it can be implemented using reflection. It would be great if you could create a new ticket for the tracker or even work with the patch if you are interested.

Hurrah!

Answer 2

Another solution that I use in my projects:

 class ProcessCallbackException extends Exception { public function __construct(\Closure $callback, $message = "", Exception $previous = null) { parent::__construct($message, 0, $previous); $this->callback = $callback; } public $callback; } class AccessDeniedException extends ProcessCallbackException { public function __construct($message = null) { $f = function() { return app()->redirect('/login'); }; parent::__construct($f, $message); } } # Handle your special errors $app->error(function (\Exception $e, $code) { if ($e instanceof ProcessCallbackException) { /** @var ProcessCallbackException $callbackException */ $callbackException = $e; return call_user_func($callbackException->callback); } else return null; });