ds-site/Classes/ViewHelpers/Format/IdViewHelper.php

<?php

declare(strict_types=1);

/*
 * Copyright (C) 2021 Daniel Siepmann <coding@daniel-siepmann.de>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
 * 02110-1301, USA.
 */

namespace DanielSiepmann\DsSite\ViewHelpers\Format;

use TYPO3Fluid\Fluid\Core\Rendering\RenderingContextInterface;
use TYPO3Fluid\Fluid\Core\ViewHelper\AbstractViewHelper;
use TYPO3Fluid\Fluid\Core\ViewHelper\Traits\CompileWithContentArgumentAndRenderStatic;
use TYPO3\CMS\Core\Utility\GeneralUtility;

/**
 * Formats a given string to be a valid HTML id attribute value.
 */
class IdViewHelper extends AbstractViewHelper
{
    use CompileWithContentArgumentAndRenderStatic;

    public function initializeArguments(): void
    {
        $this->registerArgument('value', 'string', 'string to format');
    }

    public static function renderStatic(
        array $arguments,
        \Closure $renderChildrenClosure,
        RenderingContextInterface $renderingContext
    ) {
        $value = $renderChildrenClosure();
        if (!is_string($value) && !(is_object($value) && method_exists($value, '__toString'))) {
            return $value;
        }
        $value = (string)$value;
        $value = str_replace(' ', '_', $value);
        $value = preg_replace('#\W#', '', $value) ?? '';
        $value = GeneralUtility::underscoredToUpperCamelCase($value);
        $value = lcfirst($value);
        return $value;
    }
}