mrm_be/Classes/Hooks/PageLayoutView/MrmbeCmMaintenancePreviewRenderer.php

<?php
namespace Meramo\mrm_be\Hooks\PageLayoutView;

use \TYPO3\CMS\Core\Utility\GeneralUtility;
use \TYPO3\CMS\Backend\View\PageLayoutViewDrawItemHookInterface;
use \TYPO3\CMS\Backend\View\PageLayoutView;
use \TYPO3\CMS\Core\Service\FlexFormService;
use \TYPO3\CMS\Extbase\Utility\LocalizationUtility;

/**
 * Contains a preview rendering for the page module for CTYPE="mrm_be_cm_maintenance"
 */
class MrmBeCmMaintenancePreviewRenderer implements PageLayoutViewDrawItemHookInterface
{
     /**
    * Preprocesses the preview rendering of a content element of type "My new content element"
    *
    * @param \TYPO3\CMS\Backend\View\PageLayoutView $parentObject Calling parent object
    * @param bool $drawItem Whether to draw the item using the default functionality
    * @param string $headerContent Header content
    * @param string $itemContent Item content
    * @param array $row Record row of tt_content
    * @return void
    */
    public function preProcess(
        PageLayoutView &$parentObject,
        &$drawItem,
        &$headerContent,
        &$itemContent,
        array &$row
    )
    {
        if($row['CType'] === 'mrm_be_cm_maintenance') {
            // Hier wird das aussehen der oben angezeigt Komponent festgelegt
            $headerContent = '<b>' . LocalizationUtility::translate('LLL:EXT:mrm_be/Resources/Private/Language/locallang_ttc.xlf:'.$row['CType'].'.title', '').'</b>';
            $ffs = GeneralUtility::makeInstance(FlexFormService::class);
            $flex = $ffs->convertFlexFormContentToArray($row['pi_flexform']);
            
            $start = $flex['starttime'];
            $start = date('d.m.Y H:i', $start);

            $end = $flex['endtime'];
            $end = date('d.m.Y H:i', $end);

            $infotext = $flex['infotext'];

            $itemContent = '<div style="display: flex; flex-direction: row; justify-content: flex-start"><img src="/typo3conf/ext/mrm_be/Resources/Public/Icons/'.$row['CType'].'.svg" style="width: 32px; height: 32px; margin-right: 6px;"><div style="display: flex; flex-direction: column; min-width: 0;"><strong>'.\TYPO3\CMS\Extbase\Utility\LocalizationUtility::translate('LLL:EXT:mrm_be/Resources/Private/Language/locallang_ttc.xlf:'.$row['CType'].'.title', '').': </strong><b>'.$flex['key'].'</b><br>'.$start.'<br>'.$end.'<br><em style="white-space:nowrap; overflow:hidden;text-overflow: ellipsis;">'.$infotext.'</em></div></div>';

            $drawItem = false;
        }
    }
}