[TASK] Add documentation and use DOK_TYPE_NEWS constant instead of number

Classes/Backend/CategoryWarningDrawer.php

@@ -26,6 +26,7 @@
 namespace SGalinski\SgNews\Backend;
 
 use SGalinski\SgNews\Domain\Model\Category;
+use SGalinski\SgNews\Domain\Model\News;
 use TYPO3\CMS\Backend\Controller\PageLayoutController;
 use TYPO3\CMS\Core\Database\Connection;
 use TYPO3\CMS\Core\Database\ConnectionPool;
@@ -36,17 +37,20 @@ use TYPO3\CMS\Core\Messaging\FlashMessageRendererResolver;
 use TYPO3\CMS\Core\Utility\GeneralUtility;
 
 /**
- *
+ * This class handles a warning message if the news is not located in a news category. It is implmeneted as a hook for
+ * $GLOBALS['TYPO3_CONF_VARS']['SC_OPTIONS']['cms/layout/db_layout.php']['drawHeaderHook'] in ext_localconf.php
  */
 class CategoryWarningDrawer {
 	/**
+	 * Renders the error message, if the given $parentObj is a news page and has no category as parent page
+	 *
 	 * @param array|NULL $params
 	 * @param PageLayoutController|NULL $parentObj
 	 * @return string
 	 * @throws \Doctrine\DBAL\Driver\Exception|\Doctrine\DBAL\DBALException
 	 */
 	public function render(array $params = NULL, PageLayoutController $parentObj = NULL): string {
-		if (!$parentObj || $parentObj->pageinfo['doktype'] !== 116) {
+		if (!$parentObj || $parentObj->pageinfo['doktype'] !== News::DOK_TYPE_NEWS) {
 			return '';
 		}