Photo upload with polymorphic relations

You can create 2 routes and pass the model to a PhotoRepository that handles the actual storing and attaching logic and inject that in each controller;

You'll need a way to tell the Photo what kind of model you're attaching it to.

I thought so, but what is repository?

@Mithridates Repository (also known as the Repository Pattern) is a class which is usually a collection of query methods for a specific entity (model or database table or maybe something else). All your queries stay in this class, you write them once and you can call them anywhere in your application where you need to query something from the database. It keeps your code DRY (Don't Repeat Yourself).

Example:

class UserRepository 
{ 
    public function getAllUsers()
    {
        return User::all();
    }
    
    public function getUserByUsername($username)
    {
        return User::where('username', $username)->first();
    }
    public function getUserById($userId)
    {
        return User::find($userId);
    }

    public function createNewUser(array $userDetails)
    {
        return User::create($userDetails);
    }
}

class UsersController extends Controller 
{
    protected $userRepository;

    public function __construct(UserRepository $userRepository)
    {
        $this->userRepository = $userRepository;        
    }

    public function index()
    {
        $users = $this->userRepository->getAllUsers();

        return view('users.index', compact('users'));
    }

    public function create(Request $request)
    {
        $this->userRepository->createNewUser($request->all());
        
        return redirect('users');
    }
}

Not the best code (it can be improved) but I just wrote it to give you an idea of what a repository is. It is simple if you understand how Object Oriented Programming (in PHP) works.