Options for Router design

router-1.php

<?php

// (1) With support for caching and URL creation:
// - can't retain Route objects; use named routes instead
// - can't use closures; static coupling to class-name only, not to method-name; use method-name convention instead

class ArticleUrl
{
    /** @var Router */
    protected $router;
    
    public function __construct(Router $router)
    {
        // retaining the Router reference
        $this->router = $router;
    }
    
    public function registerRoutes(Router $router)
    {
        $router
            ->route('/articles/<article_id:int>-<title:slug>')
            ->name('article', 'show')
            ->get(ShowArticleController::class);
    }
    
    public function show(Article $article)
    {
        return $this->router->url('article', 'show', ['id' => $article->getId(), 'title' => $article->getTitle()]);
    }
}

class ShowArticleController
{
    public function get($article_id)
    {
        return new PageResult(new ArticlePage(article_api()->getRepo()->getArticle($article_id)));
    }
}

router-2.php

<?php

// (2) NO support for caching:
// - retain references to Route objects; don't need named routes
// - dispatch via closures; static coupling to class-name and method-name

class ArticleUrl
{
    /** @var Route */
    protected $show_route;
    
    public function registerRoutes(Router $router)
    {
        $this->show_route = $router->route('/articles/<article_id:int>-<title:slug>')->get(function ($article_id) {
            return (new ArticleController)->showArticle($article_id);
        });
    }
    
    public function show(Article $article)
    {
        return $this->show_route->url(['id' => $article->getId(), 'title' => $article->getTitle()]);
    }
}

class ArticleController
{
    public function showArticle($article_id)
    {
        return new PageResult(new ArticlePage(article_api()->getRepo()->getArticle($article_id)));
    }
}

router-3.php

<?php

// (3) With support for caching, but NO support for URL creation:
// - can't retain Route objects; don't need named routes for URL creation
// - can't use closures; static coupling to class-name only, not to method-name; use method-name convention instead
// - don't need to retain Router reference: URL creation independent of Router

class ArticleUrl extends UrlHelper
{
    public function registerRoutes(Router $router)
    {
        $router
            ->route('/articles/<article_id:int>-<title:slug>')
            ->get(ShowArticleController::class);
    }
    
    public function show(Article $article)
    {
        return "/articles/{$article->getId()}-{$this->slug($article->getTitle())}";
    }
}

class ShowArticleController
{
    public function get($article_id)
    {
        return new PageResult(new ArticlePage(article_api()->getRepo()->getArticle($article_id)));
    }
}