public function publishedPostsAction()
    {
        $this->routeParam()->mapPageTo($this->queryService);

        if ($tag = $this->params()->fromRoute('tag')) {
            $collection = $this->queryService->findPublishedPostsByTag($tag);
        } else {
            $collection = $this->queryService->findPublishedPosts();
        }

        return $this->viewModelFactory()->createFor($collection);
    }