Map query params to controller arguments with Attributes

[mortenscheel]

I just noticed that Symfony has the ability to inject query params as controller arguments by using attributes: https://symfony.com/doc/current/controller.html#mapping-query-parameters-individually

Having no experience whatsoever with how dependency injection works in Laravel, I obviously had to give it a try 😆.
Here's the proof of concept I came up with. I'm not claiming that this is the way to do it, I just wanted to hear if you guys have any thoughts. Wouldn't this be a nice feature to have in Laravel? I haven't looked into it, but I suppose it might be possible to reuse some of the logic from Symfony.

In Illuminate\Routing\ResolvesRouteDependencies

protected function transformDependency(ReflectionParameter $parameter, $parameters, $skippableValue)
{
    $className = Reflector::getParameterClassName($parameter);
    // Hack start
    if (!$className && !empty($parameter->getAttributes(MapQueryParameter::class))) {
        if (($value = request()->query($parameter->getName())) !== null) {
            return match($parameter->getType()?->getName()){
                'int' => (int) $value,
                'float' => (float) $value,
                'bool' => (bool) $value,
                default => $value
            };
        }
    }
    // Hack end

    // If the parameter has a type-hinted class, we will check to see if it is already in
    // the list of parameters. If it is we will just skip it as it is probably a model
    // binding and we do not want to mess with those; otherwise, we resolve it here.
    if ($className && ! $this->alreadyInParameters($className, $parameters)) {
        $isEnum = (new ReflectionClass($className))->isEnum();

        return $parameter->isDefaultValueAvailable()
            ? ($isEnum ? $parameter->getDefaultValue() : null)
            : $this->container->make($className);
    }

    return $skippableValue;
}

And then inject query params in controller actions like this:

public function index(#[MapQueryParameter] int $type)
{
    dd($type);
}

The argument type is optional, and you can give it a default value as usual.

EDIT: I've made a quick prototype package that adds this feature. It uses Symfony's QueryParameterValueResolver to resolve, validate and cast the values. https://github.com/mortenscheel/inject-query-params

[ghost]

Hi. Can you please explain the gains of doing this?

Why

    public function index(Request $request): Response
    {
        dd($request->input('name');
    }

is not enough?

Why add overhead to the framework?

[mortenscheel]

Why

It's certainly not a necessary feature. It's just a convenient alternative. And it's just a simple proof of concept. If you look at the Symfony link you can see that there are lots of other possibilities. Like mapping the query parameters to a DTO.

Regarding overhead, I'm pretty sure it's negligible.

[ghost]

Thank you. If it can be implemented as a package to not be included in the core, it would get my vote.

[mortenscheel]

Challenge accepted.
https://github.com/mortenscheel/inject-query-params

[ghost]

Congrats. Only one thing I see off in the readme of your lib. Validation exception. Query parameters are by definition optional. If you want to make them mandatory, you embed them in the route => you will get them in the controller function without attributes.

[mortenscheel]

Yeah that's one of the (many) things I wasn't sure how should be handled. Symfony throws a 404 which might actually make more sense, since required params sort or become part of the route signature.

I'm still not sure if this is a feature I'd use myself, but it has been a great learning experience. And I could see it being added to the Laravel core at some point.

[mindaugasvcs]

Jealous thieves

[macropay-solutions]

@mindaugasvcs you can "steal" our auto filter for cruFd and implement it using Doctrine in Symfony like we implemented it via Eloquent.

[shaedrich]

Can you achieve this via custom contextual attributes container binding?