[TYPO3-mvc] own sorting with extbase

[Philipp]

I managed this by overloading the Typo3DbBackend Class
Can be done via Typoscript

There is extended the method parseOrderings for that purpose.

protected function parseOrderings(array $orderings, \TYPO3\CMS\Extbase\Persistence\Generic\Qom\SourceInterface $source, array &$sql) {
		foreach ($orderings as $propertyName => $order) {
			switch ($order) {
				case \TYPO3\CMS\Extbase\Persistence\Generic\Qom\QueryObjectModelConstantsInterface::JCR_ORDER_ASCENDING:

				case \TYPO3\CMS\Extbase\Persistence\QueryInterface::ORDER_ASCENDING:
					$order = 'ASC';
					break;
				case \TYPO3\CMS\Extbase\Persistence\Generic\Qom\QueryObjectModelConstantsInterface::JCR_ORDER_DESCENDING:

				case \TYPO3\CMS\Extbase\Persistence\QueryInterface::ORDER_DESCENDING:
					$order = 'DESC';
					break;
				default:
					throw new \TYPO3\CMS\Extbase\Persistence\Generic\Exception\UnsupportedOrderException('Unsupported order encountered.', 1242816074);
			}
			$className = '';
			$tableName = '';
			
			/**
			 * MODIFICATION START
			 * This way we enable the use of a function inside ordering
			 * this is mysql specific but its needed for our listMode Priority feature
			 * This way we can get a ordered list but put some specific objects on top of the list
			 */
			if (stripos($propertyName,'FIELD(') !== FALSE) {
				$parts = explode(',',str_replace(')','',$propertyName));
				$property = str_ireplace('FIELD(','',array_shift($parts));
				$values = array_filter(array_filter($parts,function($value){
					return !preg_match_all("/[^\w]/",$value);
				}));
				$className = $source->getNodeTypeName();
				$tableName = $this->dataMapper->convertClassNameToTableName($className);
				$columnName = $this->dataMapper->convertPropertyNameToColumnName($property, $className);
				$fieldString = 'FIELD('.$tableName.'.'.$columnName.','.implode(',',$values).')';
				$sql['orderings'][] = $fieldString. ' ' . $order;
			} else {
				/**
				 * MODIFICATION END
				 */
				if ($source instanceof \TYPO3\CMS\Extbase\Persistence\Generic\Qom\SelectorInterface) {
					$className = $source->getNodeTypeName();
					$tableName = $this->dataMapper->convertClassNameToTableName($className);
					while (strpos($propertyName, '.') !== FALSE) {
						$this->addUnionStatement($className, $tableName, $propertyName, $sql);
					}
				} elseif ($source instanceof \TYPO3\CMS\Extbase\Persistence\Generic\Qom\JoinInterface) {
					$tableName = $source->getLeft()->getSelectorName();
				}
				$columnName = $this->dataMapper->convertPropertyNameToColumnName($propertyName, $className);
				if (strlen($tableName) > 0) {
					$sql['orderings'][] = $tableName . '.' . $columnName . ' ' . $order;
				} else {
					$sql['orderings'][] = $columnName . ' ' . $order;
				}
			}
		}

does the job but of course its not the best way.