Merge pull request #4031 from nextcloud/enh/reference-link

implement reference provider

Author: dartcafe

CHANGELOG.md

@@ -24,6 +24,7 @@ All notable changes to this project will be documented in this file.
  - Delete polls without the need to archive them first
  - Collapsible poll description
  - Transfer polls to another owner by the current poll owner or the administration
+ - Added reference provider for link previews
 
 ## [7.4.1] - 2024-03-07
 ### New

img/polls.svg

@@ -56,6 +56,7 @@
 use OCA\Polls\Model\Settings\SystemSettings;
 use OCA\Polls\Notification\Notifier;
 use OCA\Polls\Provider\SearchProvider;
+use OCA\Polls\Reference\PollReferenceProvider;
 use OCA\Polls\UserSession;
 use OCP\AppFramework\App;
 use OCP\AppFramework\Bootstrap\IBootContext;
@@ -127,6 +128,7 @@ public function register(IRegistrationContext $context): void {
 
 		$context->registerSearchProvider(SearchProvider::class);
 		$context->registerDashboardWidget(PollWidget::class);
+		$context->registerReferenceProvider(PollReferenceProvider::class);
 	}
 
 	/**

lib/AppInfo/Application.php

@@ -0,0 +1,132 @@
+<?php
+
+declare(strict_types=1);
+/**
+ * SPDX-FileCopyrightText: 2025 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+namespace OCA\Polls\Reference;
+
+use Exception;
+use OCA\Polls\AppInfo\Application;
+use OCA\Polls\Exceptions\ForbiddenException;
+use OCA\Polls\Exceptions\NotFoundException;
+use OCA\Polls\Service\PollService;
+use OCP\Collaboration\Reference\IReference;
+use OCP\Collaboration\Reference\IReferenceProvider;
+use OCP\Collaboration\Reference\Reference;
+use OCP\IL10N;
+use OCP\IURLGenerator;
+
+class PollReferenceProvider implements IReferenceProvider {
+
+	/** @psalm-suppress PossiblyUnusedMethod */
+	public function __construct(
+		private PollService $pollService,
+		private IURLGenerator $urlGenerator,
+		private IL10N $l10n,
+		private ?string $userId,
+	) {
+	}
+
+	/**
+	 * @inheritDoc
+	 */
+	public function matchReference(string $referenceText): bool {
+		// validate url by checking if it contains a poll id; This is valid for internal polls
+		return ($this->extractPollId($referenceText) !== 0);
+	}
+
+	private function extractPollId($referenceText): int {
+		$matchingUrls = [
+			$this->urlGenerator->getAbsoluteURL('/apps/' . Application::APP_ID . '/vote'), // poll url base without index.php
+			$this->urlGenerator->getAbsoluteURL('/index.php/apps/' . Application::APP_ID . '/vote'), // poll url base with index.php
+		];
+
+		foreach ($matchingUrls as $url) {
+			preg_match('/^' . preg_quote($url, '/') . '?\/([0-9]+)$/', $referenceText, $matches);
+			if ($matches && count($matches) > 1) {
+				return (int)$matches[1];
+			}
+		}
+		return 0;
+	}
+
+
+	/**
+	 * @inheritDoc
+	 */
+	public function resolveReference(string $referenceText): ?IReference {
+		if ($this->matchReference($referenceText)) {
+			$pollId = $this->extractPollId($referenceText);
+
+			if ($pollId) {
+				try {
+					$poll = $this->pollService->get($pollId);
+					$title = $this->l10n->t('Poll') . ': ' . $poll->getTitle();
+					$description = $poll->getDescription();
+					$ownerId = $poll->getUser()->getId();
+					$ownerDisplayName = $poll->getUser()->getDisplayName();
+					$url = $poll->getVoteUrl();
+
+				} catch (NotFoundException $e) {
+					$pollId = 0;
+					$title = $this->l10n->t('404 - Poll not found');
+					$description = $this->l10n->t('This poll does not exist (anymore).');
+					$ownerId = null;
+					$ownerDisplayName = $this->l10n->t('No one.');
+					$url = null;
+
+				} catch (ForbiddenException $e) {
+					$owner = $this->pollService->getPollOwnerFromDB($pollId);
+					$title = $this->l10n->t('Access denied');
+					$ownerDisplayName = $owner->getDisplayName();
+					$description = $this->l10n->t('You have no access to this poll. Contact %s if you think this is a mistake.', $ownerDisplayName);
+					$ownerId = $owner->getId();
+					$url = $referenceText;
+
+				} catch (Exception $e) {
+					// skip the reference silently
+					return null;
+				}
+
+				$imageUrl = $this->urlGenerator->getAbsoluteURL(
+					$this->urlGenerator->imagePath(Application::APP_ID, 'polls.svg')
+				);
+
+				$reference = new Reference($referenceText);
+				$reference->setTitle($title);
+				$reference->setDescription($description ? $description : $this->l10n->t('No description available.'));
+				$reference->setImageUrl($imageUrl);
+				$reference->setRichObject(Application::APP_ID . '_poll_widget', [
+					'id' => $pollId,
+					'poll' => [
+						'id' => $pollId,
+						'title' => $title,
+						'description' => $description ? $description : $this->l10n->t('No description available.'),
+						'ownerDisplayName' => $ownerDisplayName,
+						'ownerId' => $ownerId,
+						'url' => $url,
+					],
+				]);
+				return $reference;
+			}
+		}
+
+		return null;
+	}
+
+	public function getCachePrefix(string $referenceId): string {
+		$pollId = $this->extractPollId($referenceId);
+		if ($pollId !== 0) {
+			return (string)$pollId;
+		}
+
+		return $referenceId;
+	}
+
+	public function getCacheKey(string $referenceId): ?string {
+		return $this->userId ?? '';
+	}
+}

lib/Reference/PollReferenceProvider.php

@@ -178,6 +178,14 @@ public function get(int $pollId) {
 		}
 	}
 
+	public function getPollOwnerFromDB(int $pollId): UserBase {
+		try {
+			$poll = $this->pollMapper->find($pollId);
+			return $poll->getUser();
+		} catch (DoesNotExistException $e) {
+			throw new NotFoundException('Poll not found');
+		}
+	}
 	/**
 	 * Add poll
 	 */