PHP Slices MVC Framework Concept

gistfile1.php

<?php
class UserController extends UserCollection implements Slice\RestController {
	use \Slice\HttpController;
	use \Slice\RESTController;
	use \Slice\Response\ToJson;

	protected function action($request, $user)
	{
		if ($request->GET('/')) 
			return $this->list($request['offset']);
		if ($request->GET('/:id')) 
			return $this->fetch($request['id']);
		if ($request->POST('/') and $user->is('admin')) 
			return [$this->create($request['user']), 'user was sucessfully created')];
		return $this->restRoutes($request, $user);
	}

}

class ViewUserController extends UserController
{
	use \Slice\View;

	function index($request, $user)
	{
		parent::index($request, $user);
		$theme = $user->session('theme');
		return new TwigView('user/index.twig', ['theme' => $theme]);
	}	
}

class CachedUserController extends UserController
{
	use \Slice\Cache

	protected function cache($request, $user)
	{
		if (!$user) $this->setCache('index')->for(86400);		

	}
}