How to catch a Policy response exception?

Before calling the render callbacks you registered, Laravel calls its internal ->prepareException(...) method:

https://github.com/laravel/framework/blob/35470afd598df6d8060ae106f2e4a82c6ace9272/src/Illuminate/Foundation/Exceptions/Handler.php#L314

And this method converts the AuthorizationException to a AccessDeniedHttpException:

https://github.com/laravel/framework/blob/35470afd598df6d8060ae106f2e4a82c6ace9272/src/Illuminate/Foundation/Exceptions/Handler.php#L362-L375

So your render callbacks for a AuthorizationException will never get called.

On the bright side you can get the previous exception from that one, check if it is an AuthorizationException and check the code for it:

$this->renderable(function (AccessDeniedHttpException $e, $request) {
    $previous = $e->getPrevious();

    if ($previous instanceof AuthorizationException) {
        // assuming ->respondWithError(...) is a private method
        // on your handler
        return $this->respondWithError($e->getCode() ?: 1010);
    }
    
    // let handler follow its course, AccessDeniedHttpException
    // is thrown from other places in the framework
    // unrelated to the Policies flow
    return null; 
});

Thanks for the answer, Rodrigo!

I'm just curious why can't I work with native Laravel exceptions and not deal with Symfony's? I don't clearly understand the logic behind the decision for prepareException. I'm throwing a native Laravel exception with payload with Response::deny() and can't catch it without tricky checkings and involving Symfony classes. I feel it should be some recommended beautiful way to do it :)

Well, they changed how the exception handler works a bit on Laravel 8.

I guess they convert to a symfony exception as it might have some helpers in place to set correct headers and response related stuff. The Symfony HTTP component is used many places by Laravel to handle HTTP requests and responses.

If you want to use the old-scholl (pre Laravel 8) approach, you can override the handler's render method on your app's exception handler instance, and catch the exception before calling the parent method:

<?php

namespace App\Exceptions;

// ...other imports
use Illuminate\Foundation\Exceptions\Handler as ExceptionHandler;

class Handler extends ExceptionHandler
{
    // ... other code

    public function render($request, Throwable $e)
    {
        if ($e instanceof AuthorizationException) {
            return $this->respondWithError($e->getCode() ?: 1010);
        }

        return parent::render($request, $e);
    }
}

If you do that you can skip registering the callbacks on the register method for those exceptions.

Thanks! Apparently, it's the best way to have full control over exceptions rendering. Reversed back my Laravel 7 code :)

You're welcome! Sometimes old is gold. Have a nice day =)