PHP: Use Case architecture example

ShowBlogPostsController.php

<?php

class ShowBlogPostsController
{
    /**
     * @param ShowBlogPostUseCase
     **/
    private $useCase;
    
    /**
     * @param TemplateEngine
     **/
    private $templateEngine;
    
    public function __construct(ShowBlogPostUseCase $useCase, TemplateEngine $templateEngine)
    {
        $this->useCase = $useCase;
        $this->templateEngine = $templateEngine;
    }
    
    public function showBlogPostsAction(HttpRequest $httpRequest)
    {
        $useCaseRequest = new ShowBlogPostsRequest();
        $useCaseRequest->page = $httpRequest->query->get('page');
        $useCaseRequest->categoryName = $httpRequest->query->get('category');
        
        $useCaseResponse = $this->useCase->handle($useCaseRequest);
    
        $content = $this->templateEngine->render('blog/posts', [
            'posts' => $useCaseResponse->posts,
            'all_posts_count' => $useCaseResponse->allPostsCount,
            'categories' => $useCaseResponse->categories,
        ]);
        
        return new HttpResponse($content);
    }
}

ShowBlogPostsRequest.php

<?php

class ShowBlogPostsRequest
{
    /**
     * @param int
     */
    public $page;
    
    /**
     * @param string
     **/
    public $categoryName;
}

ShowBlogPostsResponse.php

<?php

// simple DTO, but one could create getters instead of public properties ofc
class ShowBlogPostsResponse
{
    /**
     * @param Post[]
     **/
    public $posts;
    
    /**
     * @param int
     **/
    public $allPostsCount;
    
    /**
     * @param PostCategory[]
     **/
    public $categories;
}

ShowBlogPostsUseCase.php

<?php

class ShowBlogPostsUseCase
{
    /**
     * @param PostRepository
     **/
    private $postRepository;
    
    /**
     * @param CategoryRepository
     **/
    private $categoryRepository;
    
    /**
     * @param int
     **/
    private $postsLimit;
    
    public function __construct(
        PostRepository $postRepository, 
        CategoryRepository $categoryRepository, 
        $postsLimit
    ) {
        $this->postRepository = $postRepository;
        $this->categoryRepository = $categoryRepository;
        $this->postsLimit = $postsLimit;
    }
    
    public function handle(ShowBlogPostsRequest $request)
    {
        $category = $this->categoryRepository->findOneByName($request->categoryName);
        
        $posts = $this->postRepository->findByCategoryAndPage(
            $category, 
            $request->page, 
            $this->limit
        );
        
        $response = new ShowBlogPostsResponse();
        $response->posts = $posts;
        $response->allPostsCount = $this->postRepository->count();
        $response->categories = $this->categoriesRepository->findAll();
        
        return $response;
    }
}