Can I make my own ExceptionHandler ?

iPurpl3x

I am trying to send an error to the frontend while it is doing an API call. The error status should be 415.
I digged in flarum/core and I have seen that there are several ExceptionHandlers, managing different kind of Exceptions.
After some time trying different approaches, I didn't find out how I can register my own ExceptionHandler to the main ErrorHandler that is defined in core/src/Api/ApiServiceProvider.php.

clarkwinkelmann

iPurpl3x indeed there's no event or extender for that as I can see. And I can't think of any extension that has its own ExceptionHandler.

Here's something you might be able to do (I have not tested)

// Resolve the ErrorHandler singleton
$handler = app(Tobscure\JsonApi\ErrorHandler::class);
// Add yours
$handler->registerHandler(new YourExceptionHandler);

The trick is where to run that code. It needs to run after the ApiServiceProvider registers, so there should be many option. The most logical might be to register your own service provider, and run the above code in its boot method.

Related but not actually the same, https://github.com/flagrow/html-errors is an extension that registers a middleware to catch specific errors and return an alternate response. But it's for the front-end, not the API.

luceos

clarkwinkelmann check fof/sentry, from mobile.

iPurpl3x

luceos I don't really see how this can be a solution, the sentry extension is reporting the issue to the sentry instance not to the frontend right ?

As matteocontrini mentioned, making my own ExceptionHandler will not work, so should I simply throw a standard Exception and then read the error message in the frontend from the 500 HTTP error that I get ?

matteocontrini

When I tried it didn't really work: flarum/core1781

iPurpl3x

So I finally got it working as I wanted. It's not perfect but works fine.

<?php

namespace MyVendor\MyExtension\Api\Controllers;

use Psr\Http\Message\ResponseInterface;
use Psr\Http\Message\ServerRequestInterface;
use Psr\Http\Server\RequestHandlerInterface;

use MyVendor\MyExtension\Exception\MyCustomException;
use MyVendor\MyExtension\Api\ExceptionHandler\InvalidImageFileExceptionHandler;

use Tobscure\JsonApi\ErrorHandler as JsonApiErrorHandler;
use Flarum\Api\ErrorHandler;

use Throwable;

class MyControler implements RequestHandlerInterface
{
	/**
	 * @var Flarum\Api\ErrorHandler
	 */
	protected $errorHandler;

	public function __construct()
	{
		$exceptHandler = new JsonApiErrorHandler;
		$exceptHandler->registerHandler(new InvalidImageFileExceptionHandler);

		$this->errorHandler = new ErrorHandler($exceptHandler);
	}

	public function handle(ServerRequestInterface $request): ResponseInterface
	{
		try {

			// DO SOMETHING with the $request
			// SET THE $response VARIABLE

			// This code could possibly throw a MyCustomException

		} catch (Throwable $e) {
			if ($e instanceof MyCustomException) {
				return $this->errorHandler->handle($e);
			} else {
				throw $e;
			}
			
		}

		return $response;
	}
}

datitisev

iPurpl3x You can simplify the try/catch block by replacing Throwable $e with MyCustomException $e, that way there is no need to check for the instance, and other errors will still be thrown.

iPurpl3x

datitisev Oh right, I'm sometimes doing things the complicated way without reason. Thank you for noticing !