[HttpFoundation] No method to check if query param is scalar or not

[hacfi]

Description

We've noticed some exceptions caused by wrong urls where instead of ?query_param=value the user opened ?query_param[]=value. This causes a BadRequestException to be thrown: https://github.com/symfony/symfony/blob/7.4/src/Symfony/Component/HttpFoundation/InputBag.php#L40

We fixed this by using
{{ 'q' in app.request.query.all()|keys and app.request.query.all()['q'] is not iterable ? app.request.query.get('q') : '' }} instead of a simple {{ app.request.query.get('q') }} (which we used before).

I've looked into the class methods of Symfony\Component\HttpFoundation\InputBag (which is used by $request->query) and the inherited Symfony\Component\HttpFoundation\ParameterBag and there doesn't seem to be a simple way to figure out if the value is scalar or non-scalar.

So I would like to open a discussion how we can address this.

Two ideas:

• A) add an additional getValue(string $key, mixed $default = null): array|string|int|float|bool|null method that also returns an array value
• B) add a method isScalar(string $key): bool so you can check in an easier way what the value is

Example

If you use a simple

$request->query->get('q');

or in Twig

{{ app.request.query.get('q') }}

open the page that calls this code adding ?q[]=x to the url.

[webda2l]

query.all has an optional parameter.

So maybe you want: {{ app.request.query.all('q') ?: app.request.query.get('q') }} ?

[hacfi]

@webda2l Your snippet results in an error:

An exception has been thrown during the rendering of a template ("Unexpected value for parameter "q": expecting "array", got "string".").

I know technically you can figure out if it's scalar or not but for convience it would be nice to have a method to fetch a scalar value without having to wrap it with an if (to prevent an exception).

[hacfi]

I will take some time soon to prepare idea A) and create a pull request. Maybe that helps to get the discussion started.