# Exceptions response code

**URL:** <https://discourse.slimframework.com/t/exceptions-response-code/3751>\
**Category:** Questions\
**Created:** [December 23, 2019, 12:42pm UTC](https://discourse.slimframework.com/t/exceptions-response-code/3751 "2019-12-23T12:42:09Z")\
**Posts on this page:** 5\
**Page:** 1

<div class="post-metadata">

**Author:** ![killua](https://avatars.discourse-cdn.com/v4/letter/k/ce7236/32.png) [@killua](https://discourse.slimframework.com/u/killua)\
**Post date:** [December 23, 2019, 12:42pm UTC](https://discourse.slimframework.com/t/exceptions-response-code/3751/1 "2019-12-23T12:42:09Z")

</div>

Hi,

I noticed that when throwing exceptions other then slim’s http\*Exception, the response code is always 500. For example, `throw new ErrorException('Custom exception', 402);` will render the error page with correct details:

**Type:** ErrorException  
**Code:** 402  
**Message:** Custom exception  
…

But the headers respond with 500 nonetheless. I’m adding my error middleware as

```
$errorMiddleware = new ErrorMiddleware(
    $app->getCallableResolver(),
    $app->getResponseFactory(),
    $settings['displayErrorDetails'],
    $settings['logErrors'],
    $settings['logErrorDetails']
);

if ($settings['displayErrorDetails'] === false) {
    $errorHandler = $errorMiddleware->getDefaultErrorHandler();
    $errorHandler->registerErrorRenderer('text/html', HtmlErrorRenderer::class);
}

$app->add($errorMiddleware);

```

I can’t see what am I doing wrong. Any tips/help please?  
Thanks lots & Merry Christmas

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**Author:** ![odan](https://avatars.discourse-cdn.com/v4/letter/o/9de053/32.png) [@odan](https://discourse.slimframework.com/u/odan)\
**Post date:** [December 23, 2019, 8:39pm UTC](https://discourse.slimframework.com/t/exceptions-response-code/3751/2 "2019-12-23T20:39:52Z")

</div>

Slim can only map HTTP specific exceptions into a correct HTTP response and status code.

To implement a custom HTTP specific exception class try this:

```php
<?php

namespace App\Exception;

use Slim\Exception\HttpSpecializedException;

final class HttpPaymentRequiredException extends HttpSpecializedException
{
    protected $code = 402;
    protected $message = 'Payment Required.';
    protected $title = '402 Payment Required';
    protected $description = 'The requested resource requires a payment.';
}

```

**Usage** :

```php
throw new \App\Exception\HttpPaymentRequiredException($request);

```

The default Slim error handler will map the exception code into the HTTP response code.

If you want to throw non HTTP specific exceptions, you have to define a custom error handler and map the exception to the correct HTTP code.

**Example** :

```php
$errorMiddleware = $app->addErrorMiddleware($displayErrorDetails, $logErrors, $logErrorDetails);

$errorMiddleware->setErrorHandler(\App\Exception\MyCustomException::class, /* your handler */);

```

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<div class="post-metadata">

**Author:** ![killua](https://avatars.discourse-cdn.com/v4/letter/k/ce7236/32.png) [@killua](https://discourse.slimframework.com/u/killua)\
**Post date:** [December 24, 2019, 1:00am UTC](https://discourse.slimframework.com/t/exceptions-response-code/3751/3 "2019-12-24T01:00:45Z")

</div>

@odan, for explaining! I played a bit with re-throwing exceptions manually such as

```
<?php
public function read(Request $request, Response $response, array $args = []): Response
{
    $auth = new Auth($this->db);
    try {
        $users = $auth->user_read($args['uid']);
    } catch (Throwable $e) {
        if ($e->getCode() == 450) { throw new HttpNotFoundException($request, 'User not found.'); }
        if ($e->getCode() == 550) { throw new HttpBadRequestException($request, 'Wrong user id.'); }
        else { throw new HttpBadRequestException($request, 'Something went wrong, sorry.'); }
    }

```

which basically replaces a generic exception (i.e. a validation exception in user\_read() function) with a friendlier and more relevant explanation which may change depending on where user\_read() is used. I.e.:

- when loading information about an authenticated user on each page load, i’d return a 401/unauthenticated if validation fails in user\_read()
- when showing a user’s profile, the user\_read() would return a 404/not found on invalid input.

I suppose that writing my own exception handler is the only way to go here, which is what I totally wanted to avoid (not sure my skill set is up to par to do this correctly / optimally).

Since I didn’t find any prior art that would ease me into writing my own exception handler, it seems that hardly anyone has a need for it. This could mean, that I’m missing out important bits on how to make things simple and I’m over-engineering. Am I? Or does my use case have its validity?

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<div class="post-metadata">

**Author:** ![odan](https://avatars.discourse-cdn.com/v4/letter/o/9de053/32.png) [@odan](https://discourse.slimframework.com/u/odan)\
**Post date:** [December 24, 2019, 2:26pm UTC](https://discourse.slimframework.com/t/exceptions-response-code/3751/4 "2019-12-24T14:26:55Z")

</div>

You should distinguish between **infrastructure** specific exceptions (e.g. HttpNotFoundException, HttpBadRequestException) and **domain** specific exceptions (e.g. DomainException, ValidationException, etc…).

To map your domain specific exceptions into HTTP specific exceptions you could implement a middleware that catches your domain exceptions and re-throws them as a HTTP exception. Then you don’t have to create the mapping for each route.

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<div class="post-metadata">

**Author:** ![killua](https://avatars.discourse-cdn.com/v4/letter/k/ce7236/32.png) [@killua](https://discourse.slimframework.com/u/killua)\
**Post date:** [December 25, 2019, 8:06pm UTC](https://discourse.slimframework.com/t/exceptions-response-code/3751/5 "2019-12-25T20:06:47Z")

</div>

Thanks lots! I’ll look into handling this in a middleware.