How can I use a dynamic custom 404 template in Laravel?

Question

I have made a blogging application in Laravel 8.

The application supports themes. The active theme sis set in the settings table and the parent controller reads it from there:

class FrontendController extends Controller
{
 protected $data;
 protected $site_settings;
 protected $theme_directory;
 protected $site_name;
 protected $tagline;
 protected $owner_name;
 protected $owner_email;
 protected $twitter;
 protected $facebook;
 protected $instagram;
 protected $is_cookieconsent;
 protected $is_infinitescroll;
 protected $pages;
 protected $articles;
 protected $article_categories;
 protected $article_tags;
 protected $authors;
 public function __construct()
 {
 $this->site_settings = Settings::first();
 $this->theme_directory = $this->site_settings['theme_directory'] ?? null;
 $this->site_name = $this->site_settings['site_name'] ?? null;
 $this->tagline = $this->site_settings['tagline'] ?? null;
 $this->owner_name = $this->site_settings['owner_name'] ?? null;
 $this->owner_email = $this->site_settings['owner_email'] ?? null;
 $this->twitter = $this->site_settings['twitter'] ?? null;
 $this->facebook = $this->site_settings['facebook'] ?? null;
 $this->instagram = $this->site_settings['instagram'] ?? null;
 $this->is_cookieconsent = $this->site_settings['is_cookieconsent'] ?? null;
 $this->is_infinitescroll = $this->site_settings['is_infinitescroll'] ?? null;
 // Most recent articles
 $this->articles = Article::visible()->limit(5)->get();
 // Article categories. Get only categories with articles 
 $this->article_categories = ArticleCategory::has('articles')->get();
 // Pages
 $this->pages = Page::all();
 // Article tags
 $this->article_tags = Tag::all();
 // Authors
 $this->authors = User::withCount('articles')
 ->having('articles_count', '>', 0)
 ->orderByDesc('articles_count')
 ->get();
 $this->data = [
 'theme_directory' => $this->theme_directory,
 'site_name' => $this->site_name,
 'tagline' => $this->tagline,
 'owner_name' => $this->owner_name,
 'owner_email' => $this->owner_email,
 'twitter' => $this->twitter,
 'facebook' => $this->facebook,
 'instagram' => $this->instagram,
 'is_cookieconsent' => $this->is_cookieconsent,
 'is_infinitescroll' => $this->is_infinitescroll,
 'pages' => $this->pages,
 'articles' => $this->articles,
 'categories' => $this->article_categories,
 'tags' => $this->article_tags,
 'authors' => $this->authors,
 ];
 }
}

The ArticlesController, PagesController, etc, extend the above controller.

I have a custom 404 template for every theme. The path to it would be `resources\views\themes' .$theme_directory . '\templates404円.blade.php'.

For example, I show the custom 404 template fot a missing tag like this:

public function tag($tag_id)
{
 $tag = Tag::firstWhere('id', $tag_id);
 if ($tag) {
 $articles = Article::visible()
 ->whereHas('tags', function (Builder $query) use ($tag) {
 $query->where('id', $tag->id);
 })
 ->paginate($this->per_page);
 return view(
 'themes/' . $this->theme_directory . '/templates/index',
 array_merge($this->data, [
 'tag' => $tag,
 'articles' => $articles
 ])
 );
 }
 return redirect('/404');
}

But if I want to show it for a missig aricle in a similar way, I fail because I use

$article = Article::visible()->where('slug', $slug)->firstOrFail();
if(!$article) {
 return redirect('/404');
};
I fond a hack to solve this problem: 
$article = Article::visible()->where('slug', $slug)->first();
if(!$article) {
 return redirect('/404');
};

But using firstOrFail() is a standard for good reason, so I would rather keep it.

Questions:

1. How can I keep $article = Article::visible()->where('slug', $slug)->firstOrFail() and use the custom 404 template?
2. Is there a "global" solution for showing every theme's 404.blade.php, for all cases that apply?

• Peppermintology: You can customise how Laravel handles and renders exceptions