/** * Returns the previous and next published posts' title and id, if they exist. * * @param int $postId * @return array[] */ public function getClosestPosts($postId) { if (!is_int($postId)) { throw new \InvalidArgumentException('Post id must be an integer'); } $result = $this->postMapper->getClosestPosts($postId); return array('preceding_post' => json_decode($result['preceding_post']), 'following_post' => json_decode($result['following_post'])); }