do the early exit mechanism within the EventListener

#TODO: remove the Sabre Server-Plugin stuff.

lib/AppInfo/Application.php

@@ -49,7 +49,6 @@ public function __construct() {
 		$eventDispatcher->addListener(LoadAdditionalScriptsEvent::class, function () {
 			Util::addScript(self::APP_ID, 'gdatavaas-files-action');
 		});
-		$eventDispatcher->addServiceListener('beforeCreateFile', FileEventsListener::class);
 	}
 
 	/**
@@ -73,8 +72,8 @@ public function register(IRegistrationContext $context): void {
 			return new TagService($logger, $systemTagManager, $standardTagMapper, $silentTagMapper, $dbFileMapper);
 		}, true);
 
-		AntivirusSabrePluginAddEventListener::register($context);
-		#FileEventsListener::register($context);
+		#AntivirusSabrePluginAddEventListener::register($context);
+		FileEventsListener::register($context);
 		CacheEntryListener::register($context);
 
 		// Util::connection is deprecated, but required ATM by FileSystem::addStorageWrapper

lib/EventListener/FileEventsListener.php

@@ -2,6 +2,7 @@
 
 namespace OCA\GDataVaas\EventListener;
 
+use OC_Template;
 use OCA\Files_Versions\Versions\IVersionManager;
 use OCP\AppFramework\Bootstrap\IRegistrationContext;
 use OCP\EventDispatcher\Event;
@@ -10,9 +11,13 @@
 use OCP\Files\Events\Node\BeforeNodeWrittenEvent;
 use OCP\Files\IMimeTypeLoader;
 use OCP\Files\IRootFolder;
+use OCP\HintException;
+use OCP\IConfig;
+use OCP\IRequest;
 use OCP\IUserSession;
 use Psr\Log\LoggerInterface;
 use Sabre\DAV\Exception;
+use Sabre\DAV\Server;
 
 /** @template-implements IEventListener<BeforeNodeCopiedEvent|BeforeNodeDeletedEvent|BeforeNodeRenamedEvent|BeforeNodeTouchedEvent|BeforeNodeWrittenEvent|NodeCopiedEvent|NodeCreatedEvent|NodeDeletedEvent|NodeRenamedEvent|NodeTouchedEvent|NodeWrittenEvent> */
 class FileEventsListener implements IEventListener {
@@ -22,6 +27,9 @@ public function __construct(
 		private IMimeTypeLoader $mimeTypeLoader,
 		private IUserSession $userSession,
 		private LoggerInterface $logger,
+		private IConfig $config,
+		private Server $server,
+		private IRequest $request,
 	) {
 	}
 
@@ -32,13 +40,50 @@ public static function register(IRegistrationContext $context): void {
 
 	public function handle(Event $event): void {
 		if ($event instanceof BeforeNodeCreatedEvent) {
-			$node = $event->getNode();
-			$event->stopPropagation();
-			$exception = new Exception('virus detected', 415);
-			$trace = $exception->getTraceAsString();
-			throw $exception;
-			$this->logger->debug(BeforeNodeCreatedEvent::class . ':' . $event->getNode()->getPath());
-			return;
+			$this->server->httpResponse->setBody($this->generateBody());
+			$this->server->httpResponse->setStatus(415);
+			$this->server->sapi->sendResponse($this->server->httpResponse);
+			exit;
 		}
 	}
+
+	public function generateBody(): mixed {
+		if ($this->acceptHtml()) {
+			$templateName = 'exception';
+			$renderAs = 'guest';
+			$templateName = '425';
+		} else {
+			$templateName = 'xml_exception';
+			$renderAs = null;
+			$this->server->httpResponse->setHeader('Content-Type', 'application/xml; charset=utf-8');
+		}
+
+		$debug = $this->config->getSystemValueBool('debug', false);
+
+		$ex = new HintException('virus found', 'virus found', 415);
+		$content = new OC_Template('gdatavaas', $templateName, $renderAs);
+		$content->assign('title', 'virus found');
+		$content->assign('message', 'virus found');
+		$content->assign('remoteAddr', $this->request->getRemoteAddress());
+		$content->assign('requestID', $this->request->getId());
+		$content->assign('debugMode', $debug);
+		$content->assign('errorClass', get_class($ex));
+		$content->assign('errorMsg', $ex->getMessage());
+		$content->assign('errorCode', $ex->getCode());
+		$content->assign('file', $ex->getFile());
+		$content->assign('line', $ex->getLine());
+		$content->assign('exception', $ex);
+		$contentString = $content->fetchPage();
+		return $contentString;
+	}
+
+	private function acceptHtml(): bool {
+		foreach (explode(',', $this->request->getHeader('Accept')) as $part) {
+			$subparts = explode(';', $part);
+			if (str_ends_with($subparts[0], '/html')) {
+				return true;
+			}
+		}
+		return false;
+	}
 }