README

🧰 PHP Exception Handler built on top of Symfony Messenger component. Provides middlewares that allow you to easily re-raise exceptions, chain them, or handle with a dedicated handler.

Installation 📥

Install via composer

composer require phphd/exception-handler

Enable the bundle in the bundles.php

PhPhD\ExceptionHandler\Bundle\PhdExceptionHandlerBundle::class => ['all' => true],

Configuration ⚒️

To leverage features of this bundle, you should add phd_exception_handler middleware to the list:

framework:
    messenger:
        buses:
            command.bus:
                default_middleware: false
                middleware:
+                   - phd_exception_handler
                    - validation
                    - doctrine_transaction

The core principle of exception handling revolves around the idea that exceptions are dispatched to the corresponding bus to be handled. There must be one exception bus per one origin bus.

The exception bus name convention is straightforward: command.bus exceptions are forwarded into command.exception.bus.

framework:
    messenger:
        buses:
            command.exception.bus:
                default_middleware: false
                middleware:
                    - phd_exception_rethrow_unhandled
                    - phd_exception_chaining
                    - phd_exception_result_filter
                    -   handle_message:
                            - true

Currently, there are few exception handling middlewares provided.

Rethrowing unhandled

Middleware: phd_exception_rethrow_unhandled

In case if dispatched exception had not been handled it is rethrown back. The exception is considered as handled if handler returns a response, or throws another exception.

Exception chaining

Middleware: phd_exception_chaining

Implements automatic exceptions escalation logic with #[RaiseAs] attribute.

Result filter

Middleware: phd_exception_result_filter

Filters out all null results of exception handlers.

Usage 🚀

Re-Raising Exceptions

The simplest use-case is defining #[RaiseAs] attribute on your exception class:

use PhPhD\ExceptionHandler\Middleware\Chain\Escalator\RaiseAs;

#[RaiseAs(AccessDeniedHttpException::class, bus: 'api.exception.bus')]
final class NonWhiteListedUserException extends DomainException
{
}

In this example, any time NonWhiteListedUserException is thrown from an underlying handler, it will be raised as AccessDeniedHttpException.

As you can see, there's required attribute bus option. Since some exceptions could be thrown from multiple different contexts (hence, different buses), it is required to explicitly specify the bus from which the particular exception must be raised, so that in other scenarios another exceptions could be escalated:

use PhPhD\ExceptionHandler\Middleware\Chain\Escalator\RaiseAs;

#[RaiseAs(ImportLockedHttpException::class, bus: 'api.exception.bus')]
#[RaiseAs(RecoverableMessageHandlingException::class, bus: 'consumer.exception.bus')]
final class ImportLockedException extends RuntimeException
{
}

In this example, ImportLockedException could be thrown either in http context (api.bus), or in the mq consumer context (consumer.bus). Therefore, raised exceptions are different.

Manual Handling

The exception is dispatched down to your custom handlers, where you could either return a Response, throw a new exception, or just log it and return null so that exception will be re-thrown again.

#[AsMessageHandler('api.exception.bus')]
final readonly class InventoryExceptionHandler
{
    /** @throws Throwable */
    public function __invoke(InventoryDomainException $exception, InventoryCommand $command): ?Response
    {
        if ($exception instanceof JournalHasUnInventoriedItemException) {
            $data = $this->formatJournalException($exception);

            return new JsonResponse($data, Response::HTTP_BAD_REQUEST);
        }

        if ($exception instanceof StockItemNotVaildatedException) {
            $data = $this->formatItemException($exception, $command->getJournal());

            throw new StockItemNotValidatedHttpException($data, $exception);
        }

        return null;
    }
}

If you would like to use the same exception handler for multiple exception buses, you can do so by adding multiple #[AsMessageHandler] attributes:

#[AsMessageHandler(bus: 'command.exception.bus')]
#[AsMessageHandler(bus: 'query.exception.bus')]
final readonly class InventoryExceptionHandler
{
    // ...
}

phphd / exception-handler-bundle

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