SimplePrevNextViewHelper.php

<?php

namespace GeorgRinger\News\ViewHelpers;

    /**
     * This file is part of the TYPO3 CMS project.
     *
     * It is free software; you can redistribute it and/or modify it under
     * the terms of the GNU General Public License, either version 2
     * of the License, or any later version.
     *
     * For the full copyright and license information, please read the
     * LICENSE.txt file that was distributed with this source code.
     *
     * The TYPO3 project - inspiring people to share!
     */

/**
 * ViewHelper for a **simple** prev/next link.
 * Only the pid is taken into account, nothing else!
 *
 * # Example: Basic example
 * <code>
 *
 * <n:simplePrevNext pidList="{newsItem.pid}" news="{newsItem}" as="paginated" sortField="datetime">
 *    <f:if condition="{paginated}">
 *        <ul class="prev-next">
 *            <f:if condition="{paginated.prev}">
 *                <li class="previous">
 *                    <n:link newsItem="{paginated.prev}" settings="{settings}">
 *                        {paginated.prev.title}
 *                    </n:link>
 *                </li>
 *            </f:if>
 *            <f:if condition="{paginated.next}">
 *                <li class="next">
 *                    <n:link newsItem="{paginated.next}" settings="{settings}" class="next">
 *                        {paginated.next.title}
 *                    </n:link>
 *                </li>
 *            </f:if>
 *        </ul>
 *    </f:if>
 * </n:simplePrevNext>
 *
 * </code>
 * <output>
 *  Menu with 2 li items with the link to the previous and next news item.
 * </output>
 *
 */
class SimplePrevNextViewHelper extends \TYPO3\CMS\Fluid\Core\ViewHelper\AbstractViewHelper
{

    /** @var \TYPO3\CMS\Core\Database\DatabaseConnection */
    protected $databaseConnection;

    /* @var $dataMapper \TYPO3\CMS\Extbase\Persistence\Generic\Mapper\DataMapper */
    protected $dataMapper;

    public function __construct()
    {
        $this->databaseConnection = $GLOBALS['TYPO3_DB'];
    }

    /**
     * Inject the DataMapper
     *
     * @param \TYPO3\CMS\Extbase\Persistence\Generic\Mapper\DataMapper $dataMapper
     * @return void
     */
    public function injectDataMapper(\TYPO3\CMS\Extbase\Persistence\Generic\Mapper\DataMapper $dataMapper)
    {
        $this->dataMapper = $dataMapper;
    }

    /**
     * @param \GeorgRinger\News\Domain\Model\News $news
     * @param string $pidList this is something
     * @param string $sortField
     * @param string $as
     * @throws TYPO3\CMS\Fluid\Core\ViewHelper\Exception\InvalidVariableException
     * @return string
     */
    public function render(\GeorgRinger\News\Domain\Model\News $news, $pidList = '', $sortField = 'datetime', $as)
    {
        $neighbours = $this->getNeighbours($news, $pidList, $sortField);

        $mapped = $this->mapResultToObjects($neighbours);

        $this->templateVariableContainer->add($as, $mapped);
        $output = $this->renderChildren();
        $this->templateVariableContainer->remove($as);
        return $output;
    }

    /**
     * Map the array from DB to an understandable output
     *
     * @param array $result
     * @return array
     */
    protected function mapResultToObjects(array $result)
    {
        $out = $tmp = [];
        $count = count($result);

        switch ($count) {
            case 3:
                $tmp['prev'] = $result[0];
                $tmp['next'] = $result[2];
                break;
            case 2:
                $tmp['prev'] = $result[0];
                break;
            case 1:
                $tmp['next'] = $result[0];
                break;
            case 0:
                // no next or prev news, shit happens....
                break;
            default:
                throw new \UnexpectedValueException(sprintf('Unexpected count of "%s" which is not implemented!', $count));
        }

        foreach ($tmp as $_id => $single) {
            $out[$_id] = $this->getObject($single['uid']);
        }

        return $out;
    }

    /**
     * Get the news object from the given id
     *
     * @param int $id
     * @return mixed|null
     */
    protected function getObject($id)
    {
        $record = null;

        $rawRecord = $this->databaseConnection->exec_SELECTgetSingleRow('*', 'tx_news_domain_model_news',
            'uid=' . (int)$id);

        if (is_object($GLOBALS['TSFE']) && $GLOBALS['TSFE']->sys_language_content > 0) {
            $overlay = $GLOBALS['TSFE']->sys_page->getRecordOverlay(
                'tx_news_domain_model_news',
                $rawRecord,
                $GLOBALS['TSFE']->sys_language_content,
                $GLOBALS['TSFE']->sys_language_contentOL
            );
            if (!is_null($overlay)) {
                $rawRecord = $overlay;
            }
        }

        if (is_array($rawRecord)) {
            $className = 'GeorgRinger\\News\\Domain\\Model\\News';

            $records = $this->dataMapper->map($className, [$rawRecord]);
            $record = array_shift($records);
        }

        return $record;
    }

    /**
     * Returns where clause for the news table
     *
     * @return string
     */
    protected function getEnableFieldsWhereClauseForTable()
    {
        $table = 'tx_news_domain_model_news';
        if (is_object($GLOBALS['TSFE']) && is_object($GLOBALS['TSFE']->sys_page)) {
            return $GLOBALS['TSFE']->sys_page->enableFields($table);
        } elseif (is_object($GLOBALS['BE_USER'])) {
            return \TYPO3\CMS\Backend\Utility\BackendUtility::deleteClause($table) .
            \TYPO3\CMS\Backend\Utility\BackendUtility::BEenableFields($table) .
            \TYPO3\CMS\Core\Resource\Utility\BackendUtility::getWorkspaceWhereClause($table);
        } elseif (TYPO3_MODE === 'BE' && TYPO3_cliMode === true) {
            return '';
        } elseif(TYPO3_REQUESTTYPE & TYPO3_REQUESTTYPE_CLI) {
            return '';
        }

        throw new \UnexpectedValueException('No TSFE for frontend and no BE_USER for Backend defined, please report the issue!');
    }

    /**
     * @param \GeorgRinger\News\Domain\Model\News $news
     * @param $pidList
     * @param $sortField
     * @return array
     */
    protected function getNeighbours(\GeorgRinger\News\Domain\Model\News $news, $pidList, $sortField)
    {
        $pidList = empty($pidList) ? $news->getPid() : $pidList;

        $select = 'SELECT tx_news_domain_model_news.uid,tx_news_domain_model_news.title ';
        $from = 'FROM tx_news_domain_model_news';
        $whereClause = 'tx_news_domain_model_news.pid IN(' . $this->databaseConnection->cleanIntList($pidList) . ') '
            . $this->getEnableFieldsWhereClauseForTable();

        $query = $select . $from . '
					WHERE ' . $whereClause . ' && ' . $sortField . ' >= (SELECT MAX(' . $sortField . ')
						' . $from . '
					WHERE ' . $whereClause . ' AND ' . $sortField . ' < (SELECT ' . $sortField . '
						FROM tx_news_domain_model_news
						WHERE tx_news_domain_model_news.uid = ' . $news->getUid() . '))
					ORDER BY ' . $sortField . ' ASC
					LIMIT 3';

        $query2 = $select . $from . '
			WHERE ' . $whereClause . ' AND ' . $sortField . '= (SELECT MIN(' . $sortField . ')
				FROM tx_news_domain_model_news
				WHERE ' . $whereClause . ' AND ' . $sortField . ' >
					(SELECT ' . $sortField . '
					FROM tx_news_domain_model_news
					WHERE tx_news_domain_model_news.uid = ' . $news->getUid() . '))
			';

        $res = $this->databaseConnection->sql_query($query);
        $out = [];
        while ($row = $this->databaseConnection->sql_fetch_assoc($res)) {
            $out[] = $row;
        }
        $this->databaseConnection->sql_free_result($res);

        if (count($out) === 0) {
            $res = $this->databaseConnection->sql_query($query2);
            while ($row = $this->databaseConnection->sql_fetch_assoc($res)) {
                $out[] = $row;
            }
            $this->databaseConnection->sql_free_result($res);
            return $out;
        }
        return $out;
    }
}