/**
* 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']));
}
