Globáílní filtr a flashMessage po redirectu

Ahoj,

mám router a používám globální filtr (načítám slug z DB). Vše funguje, dokud nepotřebuji zavolat redirect po flashMessage. _fid se nepřenese a zpráva nevyskočí.

$this->flashMessage("Zpráva.");
$this->redirect("Article:show", $id);

Zjedodušený Router:

public function createRouter()
{
	$router = new RouteList;
	$router[] = new Route('<article_slug .+>', [
		null => [
			Route::FILTER_IN => function($params) { return $this->getArticleBySlug($params); },
			Route::FILTER_OUT => function($params) { return $this->getSlugByArticle($params); }
		]
	]);
	return $router;
}

private function getArticleBySlug($params)
{
	$article = $this->entityManager->getRepository(Article::class)->findOneBy(["slug" => $params["article_slug"]]);

	if ($article !== null) {
		return [
			"presenter" => "Article",
			"action" => "show",
			"id" => $article->getId()
		];
	}

	return null;
}

private function getSlugByArticle($params)
{
	if ($params["action"] == "show") {
		$article = $this->entityManager->find(Article::class, $params["id"]);

		if ($article !== null) {
			return [
				"article_slug" => $article->getSlug()
			];
		}
	}

	return null;
}