Symfony 6.1, routing and PHP 8.1 Enums

2 min readApr 15, 2022

So I was working on a Symfony 6.0 project where I wanted to try out PHP 8.1 Enums as requirements for routing. But it wasn’t possible yet.

A Symfony Controller, with a route using an Enum

Today I saw the Symfony 6.1.0-BETA1 released blog post and quickly scanned for updates regarding Enum support. And yes, a new feature was listed: [HttpKernel] Add a controller argument resolver for backed enums.

I quickly setup a testing project to play around with this. As the feature is still in beta, I used the command down below to create the project:

composer create-project symfony/skeleton symfony-enum-route -s dev

First thing I did was to create a Backed Enum. All examples seem to create a Card, so I’ll do the same.

<?php

namespace App\Enums;

Enum Card: string
{
    case HEARTS = 'hearts';
    case DIAMONDS = 'diamonds';
    case CLUBS = 'clubs';
    case SPADES = 'spades';
}

After that, I added a Controller and a Route.

<?php

namespace App\Controller;

use App\Enums\Card;
use Symfony\Bundle\FrameworkBundle\Controller\AbstractController;
use Symfony\Component\HttpFoundation\Response;
use Symfony\Component\Routing\Annotation\Route;

class DefaultController extends AbstractController
{
    #[Route('/{card}')]
    public function __invoke(Card $card): Response
    {
        return $this->json([
            'card' => $card,
        ]);
    }
}

The Card enum is typed hinted in the controller action (in the __invoke() method in this case).

Now let’s test this!

First by requesting an existing Card, so that means an existing route /hearts

http https://127.0.0.1:8000/hearts
HTTP/1.1 200 OK
Cache-Control: no-cache, private
Content-Length: 17
Content-Type: application/json
Date: Fri, 15 Apr 2022 20:05:10 GMT
X-Powered-By: PHP/8.1.4
X-Robots-Tag: noindex{
    "card": "hearts"
}

That works just fine, we get the 200 OK response as expected.

And the by requesting a non-existing Card, with the route /foobar

http https://127.0.0.1:8000/foobar
HTTP/1.1 404 Not Found
Cache-Control: no-cache, private
Content-Length: 151964
Content-Type: text/html; charset=UTF-8
Date: Fri, 15 Apr 2022 20:05:47 GMT
X-Powered-By: PHP/8.1.4
X-Robots-Tag: noindex<!-- Could not resolve the "App\Enums\Card $card" controller argument: "foobar" is not a valid backing value for enum "App\Enums\Card" (404 Not Found) -->

We get a 404 Not Found error page, as expected.

I’ve only been playing around with this for a few moments, but I think this is a very nice feature which I definitely am going to be using in the near future.

Symfony 6.1, routing and PHP 8.1 Enums

Written by coding010