feat: emit ApprovalStateChangedEvent on approval state changes

lib/Events/ApprovalStateChangedEvent.php

@@ -0,0 +1,67 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * SPDX-FileCopyrightText: 2026 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+namespace OCA\Approval\Events;
+
+use OCP\EventDispatcher\Event;
+
+/**
+ * Emitted when the approval state of a file changes:
+ * requested, approved or rejected.
+ *
+ * It is dispatched right before the corresponding system tag is
+ * (un)assigned, so listeners that react to tag assignment events
+ * (e.g. workflow engines) already have the context available.
+ *
+ * Next to the user who performed the action, it carries the ID of the
+ * user who requested the approval, so listeners can act on behalf of
+ * the requester and not only of the user who performed the latest action.
+ */
+class ApprovalStateChangedEvent extends Event {
+
+	public function __construct(
+		private int $fileId,
+		private int $ruleId,
+		private int $newState,
+		private ?string $actorUserId,
+		private ?string $requesterUserId,
+	) {
+		parent::__construct();
+	}
+
+	public function getFileId(): int {
+		return $this->fileId;
+	}
+
+	public function getRuleId(): int {
+		return $this->ruleId;
+	}
+
+	/**
+	 * One of Application::STATE_PENDING, Application::STATE_APPROVED or Application::STATE_REJECTED
+	 */
+	public function getNewState(): int {
+		return $this->newState;
+	}
+
+	/**
+	 * User who performed the action:
+	 * the requester on request, the approver on approve/reject
+	 */
+	public function getActorUserId(): ?string {
+		return $this->actorUserId;
+	}
+
+	/**
+	 * User who requested the approval, if known
+	 */
+	public function getRequesterUserId(): ?string {
+		return $this->requesterUserId;
+	}
+}

lib/Service/ApprovalService.php

@@ -10,8 +10,10 @@
 use DateTime;
 use OCA\Approval\Activity\ActivityManager;
 use OCA\Approval\AppInfo\Application;
+use OCA\Approval\Events\ApprovalStateChangedEvent;
 use OCA\Approval\Exceptions\OutdatedEtagException;
 use OCP\App\IAppManager;
+use OCP\EventDispatcher\IEventDispatcher;
 use OCP\Files\Config\ICachedMountFileInfo;
 use OCP\Files\Config\IUserMountCache;
 use OCP\Files\FileInfo;
@@ -50,6 +52,7 @@ public function __construct(
 		private LoggerInterface $logger,
 		private ?string $userId,
 		private IUserMountCache $userMountCache,
+		private IEventDispatcher $eventDispatcher,
 	) {
 	}
 
@@ -381,8 +384,17 @@ public function approve(int $fileId, ?string $userId, string $etag, string $mess
 				try {
 					if ($this->tagObjectMapper->haveTag((string)$fileId, 'files', $rule['tagPending'])
 						&& $this->userIsAuthorizedByRule($userId, $rule, 'approvers')) {
+						// get the requester before storeAction() replaces the pending activity row
+						$pendingAction = $this->ruleService->getLastAction($fileId, $ruleId, Application::STATE_PENDING);
+
 						// store activity in our tables
 						$this->ruleService->storeAction($fileId, $ruleId, $userId, Application::STATE_APPROVED, $message);
+
+						// dispatch before the tags change so listeners reacting to the tag events have the context
+						$this->eventDispatcher->dispatchTyped(
+							new ApprovalStateChangedEvent($fileId, $ruleId, Application::STATE_APPROVED, $userId, $pendingAction['userId'] ?? null)
+						);
+
 						// Change tags
 						$this->tagObjectMapper->assignTags((string)$fileId, 'files', $rule['tagApproved']);
 						$this->tagObjectMapper->unassignTags((string)$fileId, 'files', $rule['tagPending']);
@@ -424,9 +436,17 @@ public function reject(int $fileId, ?string $userId, string $etag, string $messa
 				try {
 					if ($this->tagObjectMapper->haveTag((string)$fileId, 'files', $rule['tagPending'])
 						&& $this->userIsAuthorizedByRule($userId, $rule, 'approvers')) {
+						// get the requester before storeAction() replaces the pending activity row
+						$pendingAction = $this->ruleService->getLastAction($fileId, $ruleId, Application::STATE_PENDING);
+
 						// store activity in our tables
 						$this->ruleService->storeAction($fileId, $ruleId, $userId, Application::STATE_REJECTED, $message);
 
+						// dispatch before the tags change so listeners reacting to the tag events have the context
+						$this->eventDispatcher->dispatchTyped(
+							new ApprovalStateChangedEvent($fileId, $ruleId, Application::STATE_REJECTED, $userId, $pendingAction['userId'] ?? null)
+						);
+
 						// Change tags
 						$this->tagObjectMapper->assignTags((string)$fileId, 'files', $rule['tagRejected']);
 						$this->tagObjectMapper->unassignTags((string)$fileId, 'files', $rule['tagPending']);
@@ -485,6 +505,11 @@ public function request(int $fileId, int $ruleId, ?string $requesterUserId, bool
 				// store activity in our tables
 				$this->ruleService->storeAction($fileId, $ruleId, $requesterUserId, Application::STATE_PENDING);
 
+				// dispatch before the tag is assigned so listeners reacting to the tag event have the context
+				$this->eventDispatcher->dispatchTyped(
+					new ApprovalStateChangedEvent($fileId, $ruleId, Application::STATE_PENDING, $requesterUserId, $requesterUserId)
+				);
+
 				$this->tagObjectMapper->assignTags((string)$fileId, 'files', $rule['tagPending']);
 
 				// still produce an activity entry for the user who requests
@@ -530,6 +555,10 @@ public function requestViaTagAssignment(int $fileId, int $ruleId, string $reques
 		// store activity in our tables
 		$this->ruleService->storeAction($fileId, $ruleId, $requesterUserId, Application::STATE_PENDING);
 
+		$this->eventDispatcher->dispatchTyped(
+			new ApprovalStateChangedEvent($fileId, $ruleId, Application::STATE_PENDING, $requesterUserId, $requesterUserId)
+		);
+
 		// still produce an activity entry for the user who requests
 		$this->activityManager->triggerEvent(
 			ActivityManager::APPROVAL_OBJECT_NODE, $fileId,

tests/unit/Service/ApprovalServiceTest.php

@@ -10,7 +10,9 @@
 use ChristophWurst\Nextcloud\Testing\TestCase;
 use OCA\Approval\Activity\ActivityManager;
 use OCA\Approval\AppInfo\Application;
+use OCA\Approval\Events\ApprovalStateChangedEvent;
 use OCP\App\IAppManager;
+use OCP\EventDispatcher\IEventDispatcher;
 use OCP\Files\Config\IUserMountCache;
 use OCP\Files\IRootFolder;
 use OCP\ICacheFactory;
@@ -97,7 +99,8 @@ protected function setUp(): void {
 			$c->get(IL10N::class),
 			$c->get(LoggerInterface::class),
 			'user1',
-			$c->get(IUserMountCache::class)
+			$c->get(IUserMountCache::class),
+			$c->get(IEventDispatcher::class)
 		);
 
 		// add some tags
@@ -427,4 +430,38 @@ public function testRequestWithCreateSharesWhenUserCannotShareReturnsError(): vo
 
 		$this->ruleService->deleteRule($ruleId);
 	}
+
+	public function testApprovalStateChangedEventIsEmitted(): void {
+		$app = new Application();
+		$eventDispatcher = $app->getContainer()->get(IEventDispatcher::class);
+
+		$emittedEvents = [];
+		$eventDispatcher->addListener(ApprovalStateChangedEvent::class, function (ApprovalStateChangedEvent $event) use (&$emittedEvents) {
+			$emittedEvents[] = $event;
+		});
+
+		// create a file
+		$uf1 = $this->root->getUserFolder('user1');
+		$file = $uf1->newFile('eventFile.txt', 'content');
+
+		// requesting approval emits an event carrying the requester
+		$this->approvalService->request($file->getId(), $this->idRule1, 'user1', false);
+		$this->assertCount(1, $emittedEvents);
+		$event = $emittedEvents[0];
+		$this->assertSame($file->getId(), $event->getFileId());
+		$this->assertEquals($this->idRule1, $event->getRuleId());
+		$this->assertSame(Application::STATE_PENDING, $event->getNewState());
+		$this->assertSame('user1', $event->getActorUserId());
+		$this->assertSame('user1', $event->getRequesterUserId());
+
+		// approving emits an event still carrying the requester
+		$this->approvalService->approve($file->getId(), 'user1', $file->getEtag());
+		$this->assertCount(2, $emittedEvents);
+		$event = $emittedEvents[1];
+		$this->assertSame($file->getId(), $event->getFileId());
+		$this->assertEquals($this->idRule1, $event->getRuleId());
+		$this->assertSame(Application::STATE_APPROVED, $event->getNewState());
+		$this->assertSame('user1', $event->getActorUserId());
+		$this->assertSame('user1', $event->getRequesterUserId());
+	}
 }