[TASK] Make DataHandlerHook stateless

Fixes #3648

CHANGELOG.md

@@ -12,6 +12,7 @@ This project adheres to [Semantic Versioning](https://semver.org/).
 
 ### Changed
 
+- Make `DataHandlerHook` stateless (#3774)
 - Merge `Csv/AbstractListView` into `Csv/AbstractRegistrationListView` (#3771)
 - Convert the manual to the new PHP-based rendering (#3692, #3696)
 - Use PHP 7.4 language features and native type declarations

Classes/Hooks/DataHandlerHook.php

@@ -38,8 +38,6 @@ class DataHandlerHook implements SingletonInterface
  */
  private const TABLE_PLACES_ASSOCIATION = 'tx_seminars_seminars_place_mm';
 
- private DataHandler $dataHandler;
-
  private SlugGenerator $slugGenerator;
 
  public function __construct(SlugGenerator $slugGenerator)
@@ -54,31 +52,30 @@ public function __construct(SlugGenerator $slugGenerator)
  */
  public function processDatamap_afterAllOperations(DataHandler $dataHandler): void
  {
- $this->dataHandler = $dataHandler;
- $this->processEvents();
+ $this->processEvents($dataHandler);
  }
 
  /**
  * Processes all events.
  */
- private function processEvents(): void
+ private function processEvents(DataHandler $dataHandler): void
  {
- $map = ($this->dataHandler->datamap[self::TABLE_EVENTS] ?? []);
+ $map = $dataHandler->datamap[self::TABLE_EVENTS] ?? [];
 
  foreach ($map as $possibleUid => $data) {
- $uid = $this->createRealUid($possibleUid);
+ $uid = $this->createRealUid($possibleUid, $dataHandler);
  $this->processSingleEvent($uid);
  }
  }
 
  /**
  * @param int|string $possibleUid
  */
- private function createRealUid($possibleUid): int
+ private function createRealUid($possibleUid, DataHandler $dataHandler): int
  {
  return $this->isRealUid($possibleUid)
  ? (int)$possibleUid
- : (int)$this->dataHandler->substNEWwithIDs[$possibleUid];
+ : (int)$dataHandler->substNEWwithIDs[$possibleUid];
  }
 
  /**