TYPO3 middleware to offer user login status as JSON for AJAX requests

UncachedContent.php

<?php

namespace My\Ext\Middleware;

use Psr\Http\Message\ResponseInterface;
use Psr\Http\Message\ServerRequestInterface;
use Psr\Http\Server\MiddlewareInterface;
use Psr\Http\Server\RequestHandlerInterface;
use TYPO3\CMS\Core\Context\Context;
use TYPO3\CMS\Core\Http\Response;
use TYPO3\CMS\Core\Http\Stream;
use TYPO3\CMS\Core\Utility\GeneralUtility;

/**
 * Middleware to offer user login status as JSON for AJAX requests
 * Modified version of code example by Thomas Kieslich
 *
 * @author Arne-Kolja Bachstein <[email protected]>
 * @see https://www.thomaskieslich.de/blog/140-typo3-9-psr-15-middleware-am-einfachen-beispiel/
 */
class UncachedContent implements MiddlewareInterface
{

    /**
     * @param \Psr\Http\Message\ServerRequestInterface $request
     * @param \Psr\Http\Server\RequestHandlerInterface $handler
     * @return \Psr\Http\Message\ResponseInterface
     */
    public function process(
        ServerRequestInterface $request,
        RequestHandlerInterface $handler
    ): ResponseInterface {
        $normalizedParams = $request->getAttribute('normalizedParams');
        $uri = $normalizedParams->getRequestUri();

        if (strpos($uri, '/uncached/json') === 0) {
            $pathComponents = explode('/', $uri);
            $path = parse_url($pathComponents[3]);
            $command = (string) $path['path'];
            $result = '';

            if ($command) {
                $result = $this->$command();
            }

            $body = new Stream('php://temp', 'rw');
            $body->write(json_encode($result));
            return (new Response())
                ->withHeader('content-type', 'application/json; charset=utf-8')
                ->withBody($body)
                ->withStatus(200);
        }
        return $handler->handle($request);
    }

    /**
     * @return array
     */
    protected function loginStatus(): array
    {
        $context  = GeneralUtility::makeInstance(Context::class);
        $data = [
            // property isLoggedIn seems to be buggy for me in 9.5.16, so comparing id for a workaround
            'isLoggedIn' => $context->getPropertyFromAspect('frontend.user', 'id', 0) > 0,
            'groupNames' => $context->getPropertyFromAspect('frontend.user', 'groupNames', NULL),
            'id'         => $context->getPropertyFromAspect('frontend.user', 'id', NULL),
            'username'   => $context->getPropertyFromAspect('frontend.user', 'username', NULL)
        ];

        return $data;
    }

}