ViewHelper for language menu and news

Template.html

    <f:section name="LanguageMenu">
        <f:if condition="({menu.0.active} && {menu.1.available} && {n:translationAvailable(languageId: 1)}) || ({menu.1.active} && {menu.0.available} && {n:translationAvailable(languageId: 0)})">
            <div class="language-switch">
                <ul>
                  …

TranslationAvailableViewHelper.php

<?php
declare(strict_types=1);

namespace Vendor\Extension\ViewHelpers;

use GeorgRinger\News\Domain\Repository\NewsRepository;
use TYPO3\CMS\Core\Database\Query\QueryBuilder;
use TYPO3\CMS\Core\Context\Context;
use TYPO3\CMS\Core\Context\Exception\AspectNotFoundException;
use TYPO3\CMS\Core\Context\LanguageAspect;
use TYPO3\CMS\Core\Database\ConnectionPool;
use TYPO3\CMS\Core\Utility\GeneralUtility;
use TYPO3\CMS\Extbase\Object\ObjectManager;
use TYPO3\CMS\Frontend\Controller\TypoScriptFrontendController;
use TYPO3Fluid\Fluid\Core\Rendering\RenderingContextInterface;
use TYPO3Fluid\Fluid\Core\ViewHelper\AbstractViewHelper;

class TranslationAvailableViewHelper extends AbstractViewHelper
{
    public function initializeArguments(): void
    {
        $this->registerArgument('languageId', 'int', 'Lanuage ID', true);
    }

    /**
     * Returns true if the current view is a news detail view
     * and there's a translation available for the current news.
     *
     * @param array $arguments
     * @param \Closure $renderChildrenClosure
     * @param RenderingContextInterface $renderingContext
     * @return bool
     */
    public static function renderStatic(
        array $arguments,
        \Closure $renderChildrenClosure,
        RenderingContextInterface $renderingContext
    ): bool {
        if (isset($GLOBALS['_GET']['tx_news_pi1']['news'], $GLOBALS['_GET']['tx_news_pi1']['action']) &&
            $GLOBALS['_GET']['tx_news_pi1']['action'] === 'detail') {

            /** @var QueryBuilder $queryBuilder */
            $queryBuilder = GeneralUtility::makeInstance(ConnectionPool::class)
                ->getQueryBuilderForTable('tx_news_domain_model_news');

            // Default language
            if ((int)$arguments['languageId'] === 0) {
                return (bool)$queryBuilder->count('uid')
                    ->from('tx_news_domain_model_news')
                    ->where(
                        $queryBuilder->expr()->eq('uid', (int)$GLOBALS['_GET']['tx_news_pi1']['news'])
                    )
                    ->execute()
                    ->fetchColumn();
            }

            return (bool)$queryBuilder->count('uid')
                ->from('tx_news_domain_model_news')
                ->where(
                    $queryBuilder->expr()->eq('l10n_parent', (int)$GLOBALS['_GET']['tx_news_pi1']['news'])
                )
                ->execute()
                ->fetchColumn();
        }

        // Something else than a news record, show the language menu
        return true;
    }

    /**
     * @return TypoScriptFrontendController
     */
    protected static function getTypoScriptFrontendController(): TypoScriptFrontendController
    {
        return $GLOBALS['TSFE'];
    }
}