What does the PhpStorm message "'file' shortcut can be used" refer to?

I have a controller that outputs an image. It's rather simple, ending in:

    /** @var SplFileObject $attachment */
    return new BinaryFileResponse($attachment, 200, [
        'Content-Type' => $attachment->getType(),
        'Content-Length' => $attachment->getSize(),
    ]);

PhpStorm in version 2024.3.2.1 shows the following warning in a tooltip:

Symfony: 'file' shortcut can be used

What is this shortcut, and how could it be used here?

Solution

While you do not show it, your controller is very likely extending the base Symfony\Bundle\FrameworkBundle\Controller\AbstractController.

This base class has a bunch of convenience/shortcut methods to reproduce common patterns.

That allows you to do things like:

return $this->json(['foo' => 'bar']);

instead of the slightly more verbose, but functionally almost equivalent:

$payload = json_encode(['foo' => 'bar']);
$response = new JsonResponse($payload);
return $response;

Similarly, the file() method would allow you to do:

$response =  $this->file($attachment);

Note that this method doesn't accept passing the response headers (although it does set up the Content-Disposition header). So if you want to set the other two headers you are setting, you'd have to do it before returning the response:

$response->headers->set('Content-Type', $attachment->getType());
$response->headers->set('Content-Length', $attachment->getSize());

return $response;

Can't at the moment say if the changes in code would be good, convenient or necessary for you; but now you know that the file() shortcut is.

I'd imagine that that warning doesn't come from stock PhpStorm, but from the very good Symfony Support plugin, that you likely have installed.