DropzoneModifier.php

<?php
declare(strict_types=1);

namespace Pixelant\PxaMedaT3kit\Hooks;

use TYPO3\CMS\Core\Utility\GeneralUtility;
use TYPO3\CMS\FrontendEditing\EditingPanel\FrontendEditingDropzoneModifier;
use Pixelant\PxaMedaT3kit\Xclass\FrontendEditing\Service\ContentEditableWrapperService;

/**
 * Class DropzoneModifier
 * @package Pixelant\PxaMedaT3kit\Hooks
 */
class DropzoneModifier implements FrontendEditingDropzoneModifier
{
    /**
     * Keep list of grid container that has first dropzone
     *
     * @var string
     */
    protected static $containersWithContent = '';

    /**
     * @param string $table
     * @param int $editUid
     * @param array $dataArr
     * @param string $content
     * @return bool
     */
    public function wrapWithDropzone(
        string $table,
        int $editUid,
        array $dataArr,
        string &$content
    ): bool {
        if ($dataArr['tx_gridelements_container']) {
            /** @var ContentEditableWrapperService $wrapperService */
            $wrapperService = GeneralUtility::makeInstance(ContentEditableWrapperService::class);
            $params = [
                'tx_gridelements_container' => $dataArr['tx_gridelements_container'],
                'tx_gridelements_columns' => $dataArr['tx_gridelements_columns']
            ];

            $content = $wrapperService->wrapContentWithDropzone(
                $table,
                (int)$editUid,
                $content,
                -1
            );

            $containerIdentifier = $dataArr['tx_gridelements_container'] . $dataArr['tx_gridelements_columns'];

            if (!GeneralUtility::inList(self::$containersWithContent, $containerIdentifier)) {
                $content = $wrapperService->wrapContentWithDropzone(
                    $table,
                    0,
                    $content,
                    -1,
                    $params,
                    true
                );

                self::$containersWithContent .= ',' . $containerIdentifier;
            }

            $content = str_replace(
                [
                    'ondragstart="window.parent.F.dragCeStart(event)"',
                    '###GRID_DATA###'
                ],
                [
                    'ondragstart="window.parent.F.dragCeInsideGridStart(event)"',
                    sprintf('data-params="%s"', GeneralUtility::implodeArrayForUrl('', $params))
                ],
                $content
            );

            return true;
        }

        return false;
    }
}